JP2003152681A - Mobile communication system and method using multi-carrier CDMA system using scramble code - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a mobile communication system of the MC-CDMA system, a plurality of candidates are provided as optimum base stations on the mobile station side, and the correlation of each is determined to obtain the FF of the optimum cell.
The T timing is detected, and the scramble code is detected. A signal receiving method in a multicarrier CDMA mobile communication system includes a multicarrier including a plurality of subcarriers having a synchronization signal multiplied by only a synchronization signal spreading code on one or more subcarriers. Receiving a signal, obtaining a correlation value between the received multicarrier signal and the synchronization signal replica, and performing FF according to the correlation value obtained in the step.
Detecting the T timing and the reception timing of the long-period spreading code, and detecting the reception FFT timing and the scramble code of the optimal cell and the timing thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-carrier CDM using a long period spread code (scramble code).
The present invention relates to a transmission technique and a reception technique in a mobile communication system for performing spread code synchronization on the receiving side in the A system.

[0002]

2. Description of the Related Art In the following description, a "scramble code" is a "long period spreading code" in the claims.

Multi-carrier CDMA (Multi Carrier)
Code Division Multiple Access: MC-CDMA or OFDM (Orthogonal Frequency Division Multip)
lexing) modulation systems and other multi-carrier transmission systems,
The transmitting side modulates the information signal with a plurality of subcarriers, and inserts a guard interval in the transmitting signal for the purpose of reducing the waveform distortion due to the multipath delay wave.

FIG. 1 shows the configuration of a conventional MC-CDMA transmission apparatus 1000. This transmitting device 100
0 has a suitable number of data channel generation circuits 100. In each of the data channel generation circuits 100, the transmission data sequence input from the transmission data generation unit 101 is encoded in the transmission line encoder 102, and the data modulation unit 10
Data modulation is performed at 3. The multiplexing unit 104 multiplexes the pilot symbols with the modulated data sequence, and the serial-parallel conversion unit 105 performs serial-parallel conversion to obtain N / SF information symbol sequences on the frequency axis. The serial / parallel-converted N / SF number of information symbol sequences on the frequency axis are copied by the copying section 106 for each information symbol by SF number of symbols equal to the sequence length of the short cycle spreading code, and arranged on the frequency axis. . A multiplier 108 multiplies the arranged N information symbol sequences on the frequency axis by the short period spreading code generated by the short period spreading code generator 107.

In the synthesizing section 109, the symbol sequences on the frequency axis of the sequence length N multiplied by the respective short cycle spreading codes (short codes) output from the respective data channel generation circuits 100 are multiplexed. Each of the N multipliers 111 multiplies the scramble code output from the scramble code generator 110 with respect to the multiplexed symbol sequence having a sequence length N, and the inverse Fourier transform circuit (IFF)
T) 113.

The inverse Fourier transform circuit 113 converts into an orthogonal multicarrier signal of N subcarriers. Then, the GI is inserted into this multicarrier signal by the guard interval inserter 114. And the transmitter 10
00 converts the multi-carrier signal output from the guard interval inserter 114 into a radio signal and sends it to space.

In the mobile station on the receiving side, the transmitting device 100
The wireless multicarrier signal transmitted from 0 is received, and the guard interval inserted on the transmission side is removed from the received multicarrier signal. The receiving side further performs FFT (Fast Fourier Transform) on the multicarrier signal from which the guard interval has been removed to separate it into N subcarrier components, and demodulates. Therefore, the receiving side needs to detect the reception timing of the guard interval portion, that is, the FFT timing before the FFT.

As a detection method of FFT timing in a multicarrier transmission method using an OFDM modulation method,
There is known a method for detecting FFT timing by taking a correlation of guard interval portions inserted for each symbol (“Simultaneous estimation method of symbol synchronization and frequency offset of multicarrier modulation signal”, Mori, Okada, Hara). , Komaki, Morinaga, IEICE Technical Report RCS95-
70, pp. 9-16, 1995-09). Further, as the timing detection signal, the same signal is repeatedly transmitted twice, and the reception side obtains the correlation between the two symbols so that F
A method for detecting the FT timing is known ("Study on the synchronous system of the OFDM modulation method for high-speed wireless LAN", Onizawa, Mizoguchi, Kumagai, Takanashi, Morikura, IEICE technical report RCS97-210, pp.137. -142, 19
98-01).

In the MC-CDMA system, the communication party is identified by a short-cycle spreading code assigned to each communication party.
Therefore, a plurality of communicators can simultaneously communicate using the same frequency band.

[0010]

The above-mentioned MC-CDM
When the A method is used for mobile communication, it is necessary to use a scramble code to identify the base station. Therefore, the receiver for the MC-CDMA system must be able to detect the FFT timing and identify the scramble code. To enable this, the mobile station needs to detect the correlation for all scrambling codes prepared in the system and detect the scrambling code multiplied by the signal of the base station to be connected. is there.
Considering flexible scramble code allocation, the number of scramble codes prepared in the system is about several hundreds. To cope with this, it takes a long time to detect the scramble code when the mobile station starts communication. However, so far, M
C-CDMA research is mainly related to link level evaluation, and nothing related to scramble code identification is found.

The present invention has been made to solve the above problems, and an object thereof is to provide an MC-CDMA system using a scramble code for identifying each of a plurality of base stations. It is an object of the present invention to provide a transmission technique and a reception technique in a mobile communication system capable of detecting a spread code at a receiving station side with high speed and high accuracy.

The present invention also provides a signal reception technique capable of detecting the FFT timing of the optimum cell by providing a plurality of candidates as the optimum base station on the receiving side in the MC-CDMA mobile communication system. The purpose is to do.

[0013]

A first feature of the present invention for achieving the above object is to provide a short-cycle spreading code product for multiplying each of a plurality of transmission data sequences by a plurality of short-cycle spreading codes. Section, and a long-cycle spreading code multiplication section that multiplies a long-cycle spreading code common to each of the plurality of transmission data sequences multiplied by the short-cycle spreading code output from the short-cycle spreading code multiplication section. A synchronization signal generation unit for multiplying the synchronization signal data by the synchronization signal spreading code and outputting the same, and a short period spreading code and a long period spreading code output from the long period spreading code multiplication unit. Each of the transmission data sequences multiplied by is transmitted by using a plurality of subcarriers, the synchronization signal generated by the synchronization signal generator is multiplied by only the synchronization signal spread code synchronization signal One or more Subcarrier is a transmission apparatus in a mobile communication system of MC-CDMA system comprising a transmitting unit for transmitting with.

A second feature of the present invention is that a data sequence obtained by multiplying a short-period spreading code and a long-period spreading code by double is transmitted using a plurality of subcarriers, and only a synchronization signal spreading code is used. Is a transmission method in a mobile communication system, wherein the synchronization signal multiplied by is transmitted using one or more subcarriers.

A third feature of the present invention is that a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in the long-cycle spreading code group by double is used as a plurality of subcarriers. A receiving device in an MC-CDMA mobile communication system, which transmits by using a signal reception for receiving a multi-carrier signal including a synchronization signal in which only one or a plurality of sub-carriers are spread by a synchronization signal spreading code. Section, a correlator for obtaining a correlation value between the multi-carrier signal received by the signal receiving section, and a synchronization signal replica, and FFT timing and the long-cycle spreading code according to the correlation value obtained by the correlator. And a timing detection unit that detects the reception timing of the.

A fourth feature of the present invention is that a data sequence obtained by multiplying a short period spreading code and any one long period spreading code included in a long period spreading code group by a double is used as a plurality of subcarriers. A receiving device in an MC-CDMA mobile communication system, which transmits by using a signal reception for receiving a multi-carrier signal including a synchronization signal in which only one or a plurality of sub-carriers are spread by a synchronization signal spreading code. Section, a first correlator for obtaining a correlation value between the multi-carrier signal received by the signal receiving section, and a synchronization signal replica, and F according to the correlation value obtained by the first correlator.
A timing detection unit that detects an FT timing and a reception timing of the long-period spreading code, and performs an FFT according to the FFT timing detected by the timing detection unit to separate the multicarrier signal into a plurality of subcarrier components. An FFT circuit, the plurality of subcarrier components separated by the FFT circuit according to the reception timing of the long-cycle spreading code detected by the timing detection unit, and each long-cycle included in the long-cycle spreading code group. A second correlator that obtains a correlation value between a spreading code and a code sequence obtained by multiplying the short-cycle spreading code by double, and the multicarrier according to the correlation value obtained by the second correlator. A code detection unit for detecting a long-cycle spreading code for spreading a signal; a reception timing of the long-cycle spreading code detected by the timing detection unit; Using said long period spreading code No. detecting section detects, in which a demodulator circuit for demodulating the data sequence from the multicarrier signal by the signal receiving unit receives.

A fifth feature of the present invention is that a data sequence obtained by multiplying a short-period spreading code and any one long-period spreading code included in a long-period spreading code by double multiplication is used for a plurality of subcarriers. A receiving device in an MC-CDMA mobile communication system, which transmits by using a signal reception for receiving a multi-carrier signal including a synchronization signal in which only one or a plurality of sub-carriers are spread by a synchronization signal spreading code. Unit, the subcarrier separation unit for separating the multicarrier signal received by the signal receiving unit into a plurality of subcarrier components, and the synchronization signal among the plurality of subcarrier components separated by the subcarrier separation unit And a correlator for obtaining a correlation value between the subcarrier component including the sync signal replica and the correlation value obtained by the correlator. Is obtained and a timing detector for detecting the timing.

A sixth feature of the present invention is that a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in the long-cycle spreading code group by double is used as a plurality of subcarriers. A receiving device in an MC-CDMA mobile communication system, which transmits by using a signal reception for receiving a multi-carrier signal including a synchronization signal in which only one or a plurality of sub-carriers are spread by a synchronization signal spreading code. Section, a subcarrier separating section that performs FFT on the multicarrier signal received by the signal receiving section according to a plurality of FFT timings, and separates into a plurality of subcarrier components, and the subcarrier separating section separated from each other. Among a plurality of subcarrier components, a correlator that obtains a correlation value between the subcarrier component included in the synchronization signal and a synchronization signal replica, and the correlator obtains According to the correlation value, it is obtained and a timing detector for detecting the reception timing and FFT timing of the long period spreading code.

A seventh feature of the present invention is that a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in the long-cycle spreading code by double multiplication is used for a plurality of subcarriers. A receiving device in an MC-CDMA mobile communication system, which transmits by using a signal reception for receiving a multi-carrier signal including a synchronization signal in which only one or a plurality of sub-carriers are spread by a synchronization signal spreading code. Unit, the subcarrier separation unit for separating the multicarrier signal received by the signal receiving unit into a plurality of subcarrier components, and the synchronization signal among the plurality of subcarrier components separated by the subcarrier separation unit A first correlator that obtains a correlation value between a subcarrier component including a sync signal replica, and Detection unit for detecting the reception timing of the signal, the plurality of subcarrier components separated by the subcarrier separation unit according to the reception timing of the long-cycle spreading code detected by the timing detection unit, and the long cycle A second correlator that obtains a correlation value between a code sequence obtained by multiplying each long-cycle spreading code included in a spreading code group and the short-cycle spreading code by double, and the second correlator A code detection unit that detects a long-cycle spreading code that spreads the multi-carrier signal according to a correlation value, a reception timing of the long-cycle spreading code detected by the timing detection unit, and the length detected by the code detection unit. And a demodulation circuit that demodulates the data sequence from the multicarrier signal received by the signal receiving unit using a period spreading code.

An eighth feature of the present invention is that a data sequence obtained by multiplying a short-period spreading code and any one long-period spreading code included in the long-period spreading code by double multiplication is used for a plurality of subcarriers. A receiving device in a mobile communication system of MC-CDMA system which is transmitted by using a signal receiving device for receiving a multi-carrier signal including a synchronization signal in which only one or a plurality of sub-carriers are spread by a synchronization signal spreading code. Section, a subcarrier separating section that performs FFT on the multicarrier signal received by the signal receiving section according to a plurality of FFT timings, and separates into a plurality of subcarrier components, and the subcarrier separating section separated from each other. A first correlator that obtains a correlation value between a subcarrier component included in the synchronization signal and a synchronization signal replica among a plurality of subcarrier components; Seki device in response to the correlation value obtained,
A timing detection unit that detects a reception timing and an FFT timing of the long-cycle spreading code, and performs an FFT according to the FFT timing detected by the timing detection unit to separate the multicarrier signal into a plurality of subcarrier components. Depending on the reception timing of the FFT circuit and the long-cycle spreading code detected by the timing detection unit,
A plurality of subcarrier components separated by the FFT circuit,
A second correlator that obtains a correlation value between each long-cycle spreading code included in the long-cycle spreading code group and a code sequence obtained by multiplying the short-cycle spreading code by double, and the second correlator Depending on the correlation value obtained, a code detection unit for detecting a long-cycle spreading code that spreads the multi-carrier signal, a reception timing of the long-cycle spreading code detected by the timing detection unit, and the code detection unit. A demodulation circuit that demodulates the data sequence from the multicarrier signal received by the signal receiving unit using the detected long-cycle spreading code.

A ninth feature of the present invention is that a data sequence obtained by multiplying a short-period spreading code and any one long-period spreading code included in a long-period spreading code by double multiplication is used for a plurality of subcarriers. A receiving device in a mobile communication system of MC-CDMA system, which is transmitted by using a receiving device for receiving a multi-carrier signal including a synchronization signal in which only one or a plurality of sub-carriers are spread by a synchronization signal spreading code. Section, a subcarrier separating section that performs FFT on the multicarrier signal received by the signal receiving section according to each of a plurality of FFT timings, and separates into a plurality of sets of a plurality of subcarrier components, and the subcarrier separating section. A first correlator that obtains a correlation value between a subcarrier component including the synchronization signal and a synchronization signal replica among the plurality of subcarrier components separated by According to the correlation value obtained by the correlator, a timing detection unit that detects a plurality of reception timing candidates of the long-cycle spreading code, and a reception timing of the plurality of long-cycle spreading codes detected by the timing detection unit. According to each, a plurality of sub-carrier components of each of the plurality of sets, a code sequence obtained by multiplying each of the long-cycle spreading code and the short-cycle spreading code included in the long-cycle spreading code group doubly. A second correlator for obtaining a correlation value, and a code candidate for detecting each of a plurality of long-cycle spreading code candidates for spreading the multi-carrier signal according to each of the plurality of correlation values obtained by the second correlator From the detection unit, the plurality of reception timing candidates detected by the timing detection unit, and the plurality of long period spreading code candidates detected by the code candidate detection unit, the long period spreading code is selected. Of the reception timing and the long-cycle spreading code, a code detecting section, the reception timing of the long-cycle spreading code detected by the timing and code detecting section, and the long-cycle spreading code And a demodulation circuit for demodulating the data sequence from the multi-carrier signal received by the receiving unit.

A tenth feature of the present invention is that a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by double is used as a plurality of subcarriers. A receiving device in a mobile communication system of MC-CDMA system, which is transmitted by using a receiving device for receiving a multi-carrier signal including a synchronization signal in which only one or a plurality of sub-carriers are multiplied by a synchronization signal spreading code. Section, an FFT timing detection section that detects a FFT timing by detecting a correlation between a guard interval portion of the multicarrier signal received by the signal receiving section, and the FF
Of the subcarrier separation unit that performs FFT at the FFT timing detected by the T timing detection unit and separates into a plurality of subcarrier components, and the plurality of subcarrier components separated by the subcarrier separation unit, the synchronization signal is A correlator that obtains a correlation value between the subcarrier component including the sync signal replica and a timing detector that detects the reception timing of the long-cycle spreading code according to the correlation value obtained by the correlator. is there.

An eleventh feature of the present invention is that a data sequence obtained by multiplying a short-period spreading code and any one long-period spreading code included in the long-period spreading code by a double multiplication is used for a plurality of subcarriers. A receiving device in a mobile communication system of MC-CDMA system, which is transmitted by using a receiving device for receiving a multi-carrier signal including a synchronization signal in which only one or a plurality of sub-carriers are spread by a synchronization signal spreading code. Section, an FFT timing detection section for detecting FFT timing from the multicarrier signal received by the signal receiving section based on a correlation characteristic of a guard interval included therein, and the FF detected by the FFT timing detection section.
A subcarrier separation unit that performs FFT at T timing and separates into a plurality of subcarrier components, and among the plurality of subcarrier components separated by the subcarrier separation unit, a subcarrier component including the synchronization signal and a synchronization signal replica A first correlator that obtains a correlation value with, a timing detector that detects the reception timing of the long-cycle spreading code, and a timing detector that detects the reception timing of the long-period spreading code according to the correlation value obtained by the first correlator. According to the reception timing of the long-cycle spreading code, the sub-carrier component separated by the sub-carrier separating unit, each long-cycle spreading code included in the long-cycle spreading code group, and the short-cycle spreading code are divided into two. A second correlator that obtains a correlation value with a multiply multiplied code sequence;
A code detection unit that detects a long-cycle spreading code that spreads the multicarrier signal according to the correlation value obtained by the second correlator, and a reception timing of the long-cycle spreading code that is detected by the timing detection unit. And a demodulation circuit that demodulates the data sequence from the multicarrier signal received by the signal receiving unit using the long-cycle spreading code detected by the code detecting unit.

A twelfth feature of the present invention is that a data sequence obtained by multiplying a short-period spreading code and any one long-period spreading code included in a long-period spreading code by double multiplication is used for a plurality of subcarriers. In a receiving method in a mobile communication system for transmitting using, a receiving step of receiving a received signal including a plurality of subcarriers having a synchronizing signal obtained by multiplying one or a plurality of subcarriers by only a spreading code for a synchronizing signal. , The received signal received in the receiving step,
A correlation output step of outputting a correlation value with a synchronization signal replica, and a timing detection step of detecting an FFT timing and a reception timing of the long-cycle spreading code according to the correlation value output in the correlation output step. Is.

In the receiving method in the mobile communication system described above, FFT is further performed according to the FFT timing detected in the timing detecting step,
According to the separation step of separating the received signal into a plurality of subcarrier components, and the reception timing of the long period spreading code detected in the timing detection step, the subcarrier component and the long period spreading code group are included. Correlation detection step of outputting the correlation detection value of the code sequence obtained by multiplying each of the long-cycle spreading code and the short-cycle spreading code that are double multiplied, according to the correlation detection value output from the correlation detection step. , A code detecting step of detecting a long-period spreading code for spreading the received signal.

A thirteenth feature of the present invention is that a data sequence obtained by multiplying a short-period spreading code and any one long-period spreading code included in a long-period spreading code by double multiplication is used for a plurality of subcarriers. In a receiving method in a mobile communication system for transmitting using, a receiving step of receiving a received signal including a plurality of subcarriers having a synchronizing signal obtained by multiplying one or a plurality of subcarriers by only a spreading code for a synchronizing signal. , The received signal received in the receiving step,
A separation step of separating into a plurality of subcarrier components, and a correlation output that outputs a correlation value between a subcarrier component included in the synchronization signal and a synchronization signal replica among the plurality of subcarrier components separated in the separation step Step and the correlation value output in the correlation output step,
And a timing detection step of detecting the reception timing of the long-period spreading code.

In the above receiving method in the mobile communication system, the separation step performs FFT according to a plurality of FFT timings, and the timing detection step outputs the correlation output step for all the FFT timings. The target F according to the correlation value
A separation step of detecting an FT timing and a reception timing of the long-period spreading code, further performing an FFT according to the FFT timing detected in the timing detection step, and separating the reception signal into a plurality of subcarrier components; , In accordance with the reception timing of the long-cycle spreading code detected in the timing detection step, the sub-carrier component, each long-cycle spreading code included in the long-cycle spreading code group and the short-cycle spreading code. A correlation detection step of outputting a correlation detection value with a code sequence that has been double multiplied, and a code for detecting a long-cycle spreading code for spreading the received signal according to the correlation detection value output from the correlation detection step. And a detection step.

A fourteenth feature of the present invention is that a data sequence in which a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code are double-multiplied and a plurality of subcarriers are used. In a receiving method in a mobile communication system for transmitting using, a receiving step of receiving a received signal including a plurality of subcarriers having a synchronizing signal obtained by multiplying one or a plurality of subcarriers by only a spreading code for a synchronizing signal. , A separation step of performing FFT on the reception signal received in the reception step in accordance with a plurality of FFT timings and separating the reception signal into a plurality of subcarrier components, and the plurality of subcarrier components separated in the separation step. Of these, a correlation output step of outputting a correlation value between the subcarrier component included in the synchronization signal and the synchronization signal replica, and the correlation output step. In accordance with the output correlation value,
According to the timing detection step of detecting the reception timing of the long cycle spreading code, and the reception timing of the long cycle spreading code detected in the timing detection step,
A correlation detection step of outputting a correlation detection value of a code sequence in which the subcarrier component, each long-cycle spreading code included in the long-cycle spreading code group, and the short-cycle spreading code are double-multiplied, For all the FFT timings,
A code detection step of detecting the FFT timing, the reception timing of the long-cycle spreading code, and the long-cycle spreading code for spreading the received signal according to the correlation detection value output from the correlation detection step. It is a thing.

A fifteenth feature of the present invention is that a data sequence obtained by multiplying a short-period spreading code and any one long-period spreading code included in a long-period spreading code by double multiplication is used for a plurality of subcarriers. In a receiving method in a mobile communication system for transmitting using the FFT timing detecting step of detecting a correlation of a guard interval part of a received signal and detecting an FFT timing, and an FFT timing obtained in the FFT timing detecting step, an FFT is detected. Done,
A separation step of separating into a plurality of subcarrier components, and a correlation output that outputs a correlation value between a subcarrier component included in the synchronization signal and a synchronization signal replica among the plurality of subcarrier components separated in the separation step Step and the correlation value output in the correlation output step,
And a timing detection step of detecting the reception timing of the long-period spreading code.

In the above receiving method in the mobile communication system, the subcarrier component and the long period spreading code group are further included according to the reception timing of the long period spreading code detected in the timing detecting step. Correlation detection step of outputting the correlation detection value of each long-cycle spreading code and the code sequence obtained by multiplying the short-cycle spreading code with double, according to the correlation detection value output from the correlation detection step, And a code detecting step of detecting a long-period spreading code that spreads the received signal.

A sixteenth feature of the present invention is that a data sequence obtained by multiplying a short-period spreading code and any one long-period spreading code included in a long-period spreading code by a double multiplication is used for a plurality of subcarriers. A receiving device in a mobile communication system of MC-CDMA system, which is transmitted by using a receiving device for receiving a multi-carrier signal including a synchronization signal in which only one or more sub-carriers are spread by a synchronization signal spreading code. And a FFT timing detection unit that detects a plurality of FFT timing candidates based on the correlation characteristic of the guard interval included therein from the multicarrier signal received by the signal reception unit, and the FFT timing detection unit, A multiplication unit for multiplying the multicarrier signal by a signal obtained by delaying the multicarrier signal by one symbol length;
An integrator that obtains a correlation value by integrating the multiplication value multiplied by the multiplication unit over one guard interval length, and a first memory that stores the correlation value obtained by the integrator and the timing thereof are sequentially given. A second memory that stores a plurality of FFT timing candidates, and a search for each of the plurality of FFT timing candidates based on the plurality of FFT timing candidates stored in the second memory and the stored value of the first memory A search range setting unit for setting a range, first, a maximum correlation value and timing are selected from the stored values of the first memory, stored in the second memory as the FFT timing candidate # 1, and then, The search range setting unit is configured to set the search range based on the FFT timing candidates stored in the second memory and the stored value of the first memory. Select the maximum correlation value and timing from the stored value of the first memory within the search range, F
A timing detection circuit that stores the FT timing candidate # 2 in the second memory and repeats the detection until a predetermined number of FFT timing candidates set in advance is detected by the same procedure.

In the receiving device in the MC-CDMA mobile communication system, the FFT is further provided.
A plurality of subcarrier separation units that perform FFT on the multicarrier signal in each of the predetermined number of FFT timing candidates detected by the timing detection unit and separate into a plurality of subcarrier components, and each of the plurality of subcarrier separation units. A plurality of first correlators for obtaining a correlation value between a subcarrier component including the synchronization signal and a synchronization signal replica among the plurality of subcarrier components separated by According to the correlation value, a plurality of timing detection units for detecting the reception timing candidates of the long-cycle spreading code, and the reception timing candidates of the plurality of long-cycle spreading codes detected by the plurality of timing detection units, respectively. , The plurality of subcarrier components, and each long-cycle spreading code included in the long-cycle spreading code group. A plurality of second correlator for obtaining a correlation value between the short period spreading code and a code sequence multiplied doubly
A plurality of code candidate detecting units for detecting a plurality of long-cycle spreading code candidates for spreading the multi-carrier signal according to the plurality of correlation values obtained by the plurality of second correlators, respectively; From the plurality of reception timing candidates detected by the timing detection unit and the plurality of long-cycle spreading code candidates detected by the plurality of code-candidate detection units, the reception timing of the long-cycle spreading code and the long-cycle spreading code And a multi-carrier signal received by the signal receiving unit by using a timing and code detection unit for detecting the reception timing of the long-cycle spreading code and the reception timing of the long-cycle spreading code detected by the timing and code detection unit. To a demodulation circuit for demodulating the data sequence.

In the receiving device in the MC-CDMA mobile communication system, the FFT is further provided.
A plurality of first FFT circuits that perform FFT on the multi-carrier signal in each of the predetermined number of FFT timing candidates detected by the timing detection unit to separate into a plurality of sub-carrier components, and the plurality of first FFT circuits.
Of the plurality of subcarrier components separated by each circuit, a plurality of first correlators for obtaining a correlation value between a subcarrier component including the synchronization signal and a synchronization signal replica, and the plurality of first correlators, respectively. According to the correlation value obtained by FF, a timing detection unit that detects the reception timing and the FFT timing of the long-cycle spreading code, and an FF according to the FFT timing detected by the timing detection unit.
A second FFT circuit that performs T and separates the multicarrier signal into a plurality of subcarrier components, and the second FFT circuit according to the reception timing of the long-cycle spreading code detected by the timing detection unit. Second correlation for obtaining a correlation value between a plurality of separated subcarrier components, a code sequence obtained by multiplying each of the long-cycle spreading codes included in the long-cycle spreading code group and the short-cycle spreading code , A code detector for detecting a long-cycle spreading code for spreading the multi-carrier signal according to the correlation value obtained by the second correlator, and the long-cycle spreading code detected by the timing detector. And a demodulation circuit that demodulates the data sequence from the multicarrier signal received by the signal receiving unit, using the reception timing and the long-cycle spreading code detected by the code detecting unit. It can also be that there was example.

A seventeenth feature of the present invention is to detect a plurality of FFT timing candidates from a correlation characteristic of a guard interval in a signal receiving method in a mobile communication system for transmitting a code sequence by using a plurality of subcarriers. It has a step.

The eighteenth feature of the present invention is to provide a received signal and a signal obtained by delaying the received signal by one symbol length in a signal receiving method in a mobile communication system for transmitting a code sequence by using a plurality of subcarriers. A step of performing a moving average of the obtained multiplication value using the average interval as a guard interval length, and a step of adding in-phase a correlation series of a plurality of correlation values obtained by the moving average in each guard interval insertion period. And a step of detecting a plurality of FFT timing candidates from the correlation series having the same length as the guard interval insertion period obtained by the in-phase addition.

In the step of detecting a plurality of FFT timing candidates, the timing having the maximum correlation value in the correlation sequence having the same length as the guard interval insertion period obtained by the in-phase addition is determined as the first FFT. The step of setting the timing candidate and the second and subsequent FFT timing candidates each have a timing having the maximum correlation value among the remaining correlation sequences that exclude the peripheral W samples of each of the already detected FFT timing candidates as an exclusion window. By repeating the method of setting the next FFT timing candidate, a step of detecting a predetermined number of FFT timing candidates can be included.

The nineteenth feature of the present invention is to detect a plurality of FFT timing candidates from a correlation characteristic of a guard interval in a signal receiving method in a mobile communication system for transmitting a code sequence using a plurality of subcarriers. Step and FF in multiple FFT timing candidates
Performing T to separate into a plurality of subcarrier components; outputting a correlation value between the subcarrier component including the sync signal and the sync signal replica among the plurality of separated subcarrier components; A step of detecting one or a plurality of long-cycle spreading code reception timing candidates according to the correlation value; and a subcarrier component according to the detected one or a plurality of long-cycle spreading code reception timing candidates. Outputting a correlation detection value of a code sequence in which each long-cycle spreading code and a short-cycle spreading code included in the long-cycle spreading code group are multiply multiplied, and outputting for all detected FFT timing candidates Detecting the FFT timing, the reception timing of the long-cycle spreading code, and the long-cycle spreading code for spreading the received signal according to the detected correlation detection value. It is intended to.

A twentieth feature of the present invention is that a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in the long-cycle spreading code group by double is used as a plurality of subcarriers. In a method of receiving a signal in a mobile communication system for transmitting by using, a signal obtained by separating a received signal into subcarrier components by a process such as FFT, each long cycle spreading code included in the long cycle spreading code group, and the short cycle When outputting the correlation detection value with the code sequence obtained by multiplying the spread code by double, the correlation value of each symbol is added in-phase in Navg symbols (Navg is an integer of 1 or more) in the time direction, The in-phase addition value for each sub-carrier is added in-phase over Ncs sub-carriers (Ncs is an integer 1 ≦ Ncs ≦ N, where N is the number of sub-carriers) adjacent in the frequency direction, and Ncs
The in-phase addition value for each subcarrier is Nps in the frequency direction (Nps
Is an integer that satisfies 1 ≦ Nps ≦ N / Ncs) and the average correlation value is detected by adding power.

In the signal receiving method in the above mobile communication system, when Nps <(N / Ncs), (N / Nc
s) / Nps long-period spreading codes can be alternately detected in the frequency direction for each Ncs subcarrier.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 2 shows a frame structure of a transmission signal used in the MC-CDMA mobile communication system. The scramble code, which is a long-period spreading code, has a different pattern for each base station in both the frequency direction and the time direction.

FIG. 3 shows the configuration of the MC-CDMA transmission apparatus 10.1 used in the mobile communication system according to the first embodiment of the present invention. This transmitter 10.1
Is provided for each base station that transmits a radio signal. The transmitter 10.1 includes a plurality of data channel generation circuits 100.1-100. x. In each of the data channel generation circuits 100, the transmission data generation unit 101
The transmission data sequence input from the transmission line encoder 102
And the data is modulated in the data modulator 103. Then, the multiplexing unit 10 is added to the modulated data sequence.
4, the pilot symbols are multiplexed, and serial / parallel conversion is performed by serial / parallel conversion section 105 into N / SF information symbol sequences on the frequency axis. The serial / parallel converted N / SF information symbol sequences on the frequency axis are copied by the copy unit 106.
The number of symbols SF, which is equal to the sequence length of the short-cycle spreading code, is copied for each information symbol and arranged on the frequency axis. A multiplier 108 multiplies the arranged N information symbol sequences on the frequency axis by the short period spreading code generated by the short period spreading code generator 107.

In the first synthesizing section 109, the symbol sequences on the frequency axis of the sequence length N multiplied by the respective short cycle spreading codes output from the respective data channel generation circuits 100 are multiplexed. Each of the N multipliers 111 multiplies the scramble code output from the scramble code generator 110 with respect to the multiplexed symbol sequence having a sequence length N, and outputs the result to the second combining unit 112.1. The second synthesizing unit 112.1 adds the synchronization signal generating unit 12 to the symbol sequence having the sequence length N multiplied by the scramble code.
The sync signals created in 0.1 are combined.

Inverse Fourier transform device (IFFT) 113
Transforms N symbols into orthogonal multicarrier signals. The guard interval inserter 114 inserts a guard interval GI into this multicarrier signal. Then, the transmitter 10.1 uses the guard interval inserter 11
The multi-carrier signal output by 4 is converted into a radio signal and output to space.

The synchronizing signal generator 120.1 generates a synchronizing signal as follows. Data generator 121
Generates synchronization signal data (usually data common to all base stations, all of which may be 1). Data modulator 12
1 modulates the sync signal data. The synchronization signal spreading code generator 123 generates a synchronization signal spreading code. The multiplier 124 multiplies the data signal modulated by the data modulator 121 by the synchronization signal spreading code output from the synchronization signal spreading code generator 123, generates a synchronization signal, and outputs the second synchronization unit 112. Output to 1.

Next, the MC-transmitter 10.1 shown in FIG.
A method of transmitting a multi-carrier signal according to will be described. Figure 4
(A) is an example of a case where the synchronization signal generation unit 120.1 continuously transmits the synchronization signal in a plurality of specific subcarriers in the time direction. FIG. 4B shows the synchronization signal generator 1
20.1 is an example of a case where the synchronization signal is continuously transmitted in the time direction on one specific subcarrier. These synchronization signals S1 correspond to the synchronization signal spread code generator 123 with respect to the data signal D1 output from the data generator 121.
Is a signal obtained by multiplying by the spreading code C1 for synchronization signal given by.

Second combiner 1 in transmitter 10.1
12.1 continuously multiplexes the synchronization signal S1 generated by the synchronization signal generation unit 120.1 on the corresponding specific subcarrier of N subcarriers on the time axis. Then, the IFFT circuit 113 performs an inverse Fourier transform, and the guard interval inserter 114 inserts a symbol guard interval GI of a fixed length for each Fourier target time and outputs it as a multicarrier signal.

FIG. 5 (a) also shows an example in which the synchronization signal is continuously transmitted in the time direction on one specific subcarrier. However, FIG. 5A shows an example in which the sync signal generator 120.1 generates the sync signal S2 in which the repetition time τ of one scramble code pattern is equal to the pattern length of the sync signal. Sync signal S
Reference numeral 2 indicates a data series having a specific pattern in the time direction. The specific pattern can be realized by a scramble code pattern for the synchronization signal. Therefore, in the receiving mobile station that receives the multicarrier signal transmitted by this transmission method, the reception timing of the multiplication start timing of the scramble code, which is a long-period spreading code, is detected by detecting the reception timing of the synchronization signal S2 from the reception signal. Can be detected.

In FIG. 5B, the length of the synchronizing signal S3 is 1
An example in which the repetition time τ of the scramble code pattern is ½ is shown. Also in this case, the synchronization signal S3 is a sequence having a specific pattern in the time direction. Therefore, the mobile station side can limit the reception timing of the scramble code multiplication start timing by detecting the transmission timing of the synchronization signal S3 from the reception signal.

The synchronization signal generated by the synchronization signal generator 120.1 is used for the specific one or a plurality of subcarriers in the second synthesizer 112.1 by the method shown in FIGS. It is also possible to perform burst-like multiplexing on the time axis. FIG. 6A shows an example in which the synchronization signal S4 is combined with a plurality of specific subcarriers and is transmitted in burst at the same timing. FIG. 6B is an example of a case where the synchronization signal S4 is combined with one specific subcarrier and is transmitted in a burst. FIG. 6C is an example of a case where the synchronization signal S4 is combined with all subcarriers and transmitted in burst at the same timing.

FIGS. 7A and 7B are diagrams showing another method of transmitting the synchronization signal S5 used in the MC-CDMA transmission system. FIG. 7A shows the second combining unit 1.
In 12.1, the synchronization signal S5 having a constant pattern generated by the synchronization signal generation unit 120.1 is multiplexed into each of a plurality of specific subcarriers at different timings for each cycle of the scramble code, and the synchronization signal S5 is multiplexed in a burst manner. This is an example of transmission. On the mobile station side that receives such a multi-carrier signal, as shown in FIG. 7B, a plurality of subcarriers in which the synchronization signal S5 is transmitted from the reception signal and the reception timing of each synchronization signal S5 are detected. By detecting, the reception timing of the multiplication start timing of the scramble code can be detected.

Next, MC- of the second embodiment of the present invention
A CDMA transmission apparatus and transmission method will be described. In the transmitting device 10.2 shown in FIG. 8, elements common to the transmitting device shown in FIG. 3 are designated by the same reference numerals. The feature of this embodiment is that the synchronization signal generator 120.1
The point is that the serial-parallel converter 125 is provided. In the synchronization signal generation unit 120.2, the data generation unit 121 uses the synchronization signal data sequence D1 (usually data common to all base stations,
All 1 is acceptable. ) Occurs. The data D1 for synchronization signal is data-modulated by the data modulator 122, and further serial-parallel converted by the serial-parallel converter 125 to form N symbol series P1 on the frequency axis. Symbol series P
For each signal of 1, the synchronization signal spread code generator 123
The spreading code C1 for the synchronization signal generated in
26 are multiplied in the frequency direction to obtain N parallel synchronization signals S.
6 is generated and output to the second synthesis unit 112.2.

The second synthesizing unit 112.2 multiplexes the sync signal generated by the sync signal generating unit 120.2 at a specific timing. This multiplexing method is shown in FIG.
It is shown in (a) and (b).

The transmission method shown in FIGS. 9 (a) and 9 (b) is a method of transmitting the synchronization signal S6 in bursts on all subcarriers. FIG. 9A shows a case where the start time of one scramble code pattern and the transmission timing of the synchronization signal S6 are simultaneously set. Therefore, the mobile station can detect the reception timing of the scramble code multiplication start timing by detecting the reception timing of the synchronization signal S6 from the reception signal. Figure 9 (b)
In this case, the synchronization signal S6 is transmitted twice within the repetition time τ of one scramble code pattern. In this case, the transmission timing interval of the synchronization signal S6 is 1/2 of the scrambling code pattern repetition time τ. Therefore, the mobile station side can limit the reception timing of the scramble code multiplication start timing by detecting the reception timing of the synchronization signal S6 from the reception signal.

Next, the configuration of the receiving apparatus 20.1 in the mobile communication system of the MC-CDMA system of the third embodiment will be described using FIG. 10, FIG. 11 and FIG.
The scramble code reception timing detection circuit 200.1 in the receiver 20.1 has the internal configuration shown in FIG.
Detects and outputs T timing. The guard interval removal circuit 208 removes the guard interval based on the FFT timing. The FFT 209 is a fast Fourier transform circuit, and decomposes the signal output from the GI removal circuit 208 into N subcarrier frequencies and outputs the N subcarrier frequencies. The scramble identification circuit 210.1 has an internal configuration shown in FIG. 11, and identifies a scramble code from the received multicarrier signal. The demodulation circuit 300 has the internal configuration shown in FIG. 12, demodulates the received multicarrier signal using the scrambling code reception timing and the scrambling code, and obtains the original transmission data.

The detailed structure of the transmitter 20 will be described with reference to FIG. The scramble code reception timing detection circuit 200.1 inputs the multicarrier signal received by the antenna 199 to the correlator 201. On the other hand, the sync signal replica generator 202 generates preset sync signal replicas and sequentially inputs them to the correlator 201. The correlator 201 detects the correlation between the received multi-carrier signal and the synchronization signal replica, and stores the correlation value indicating each peak obtained as a result and its timing in the memory 203 of the correlation value and timing. The timing detection circuit 204 uses a correlation value and timing memory 230.
From the stored values in, select the maximum correlation value and timing,
The memory 205 is used as a scramble code reception timing.
Remember. The timing detection circuit 204 further calculates the FFT timing from the scramble code reception timing and stores it in the memory 205 as the FFT timing. The FFT timing is output from the memory 205 to the GI removal circuit 208, and the scramble code reception timing is output to the scramble code identification circuit 210.1 and the demodulation circuit 300.

After detecting the scramble code reception timing by the scramble code reception timing detection circuit 200.1, the GI removal circuit 208 removes the GI using the FFT timing output from the memory 205.
The multicarrier signal from which the GI is removed is the FFT circuit 20.
9 and is separated into the original N subcarrier components, and then input to the scramble code identification circuit 210.1.

In the scramble code identifying circuit 210. 1, the scramble code replica generator 211 synchronizes a plurality of types of preset phases, for example, 512 types of phases, by a predetermined calculation, from the scramble code receiving timing detecting circuit. Set to phase. Correlators 212 corresponding to the number of subcarriers detect the correlation between the scramble code replica generated by scramble code replica generator 211 and the output of FFT circuit 209 for each subcarrier, and input the correlation detection value to adder 213. . The adder 213 adds the correlation values for each subcarrier and stores the correlation value and its scramble code number in the memory 214 for the correlation value and code number.

The scramble code detection circuit 215 selects the maximum correlation value and the code number from the stored values of the correlation value and the code number in the memory 214, and outputs the identified scramble code number to the demodulation circuit 300.

Further, the detailed structure of the demodulation circuit 300 will be described with reference to FIG. The received multi-carrier signal is input to the circuit shown in FIG. The reception timing and number of the scramble code output from the circuit of FIG.
It is input to the scramble code generator 301 for the demodulation circuit 300.

On the other hand, the received multi-carrier signal is
It is also input to the FFT timing detection unit 302 of the demodulation circuit 300. Then, the FFT timing detection unit 302 detects the FFT timing of the multi-carrier signal, and the guard interval remover (-GI) 303 removes the GI from the multi-carrier signal. The FFT circuit 304 separates the multicarrier signal from which the guard interval has been removed into each subcarrier component. Channel estimation unit 305
After estimating the channel fluctuation value of each subcarrier, the channel fluctuation is compensated by the multiplier 306. In the multiplier 307, the scramble code generated by the scramble code generator 301 is multiplied in the subcarrier direction by the symbol of each subcarrier whose channel fluctuation has been compensated. Further, the multiplier 308 multiplies the symbol multiplied by the scramble code by the corresponding short code in the subcarrier direction. The short code is provided by the short code generator 309. The combiner 310 combines the SF symbols and despreads them. The despread symbol is converted into a parallel-serial converter (P / S) 311.
Then, the data is subjected to parallel-serial conversion, and then restored in the demodulator 312 and the decoder 313 to take out the original data.

A method of receiving a multi-carrier signal by the receiver 20.1 in the MC-CDMA mobile communication system having the above configuration will be described below. FIG.
11 is a flowchart showing a signal reception process by the reception device 20.1 of FIG. 10. First, the correlation between the received signal including all subcarrier components before performing FFT and the synchronization signal replica is detected (S101). The FFT timing, that is, the symbol timing and the reception timing of the scramble code are obtained at the same time according to the timing of obtaining the maximum correlation value (S102).

Subsequently, FFT is performed at the detected FFT timing to separate the received signal into subcarrier components (S103). In addition, at the reception timing of the detected scramble code, the correlation between the received signal separated into each subcarrier component after FFT and each scramble code is detected (S104), and the scramble code having the maximum correlation value is received. The signal is detected as a scramble code for spreading (S105).

Demodulation circuit 300 in receiver 20.1.
Descrambles the multicarrier signal using the scramble code thus detected, and further demodulates and decodes the data signal to extract the original data sequence.

Next, MC- of the fourth embodiment of the present invention
A receiving device in a CDMA mobile communication system will be described with reference to FIG. The receiving device 20.2 of the fourth embodiment has the same functional block configuration as the receiving device 20.1 shown in FIG. 10, but has a configuration of a scramble code reception timing detection circuit and a scramble code identification circuit. Is different. This will be described.

The scramble code reception timing detection circuit 200.2 receives the multi-carrier signal and outputs a plurality of synchronization signal correlation detection circuits 2010.1 to 2010. Input to m. On the other hand, in the FFT timing setting circuit 2014, each sync signal correlation detection circuit 2010. x (x = 1,
2, ..., M), the FFT timing is set.
Each sync signal correlation detection circuit 2010. At x, the guard interval removal circuit 2015 removes GI from the multicarrier signal using the FFT timing. The multicarrier signal from which the GI has been removed is input to the FFT circuit 2016, and separated into a plurality of subcarrier components by the FFT circuit 2016. Of the separated subcarrier components, only the subcarrier component in which the synchronization channel is multiplexed is input to the correlator 2012. On the other hand, the synchronization signal replica generator 2013 generates a synchronization signal replica,
Input to the correlator 2012. Correlator 2012 uses FFT
The correlation between the output and the synchronization signal replica is detected, and the correlation value of each subcarrier is input to the adder 207. The adder 207 adds the correlation values in each subcarrier,
The correlation value and its timing are stored in the memory 203.

The timing detection circuit 204 selects the maximum correlation value and timing from the m correlation values and the stored value of the timing in the memory 203, and stores them in the memory 205 as the scramble code reception timing. The timing detection circuit 204 further calculates the FFT timing from the scramble code reception timing and stores it in the memory 205 as the FFT timing. The FFT timing is output from the memory 205 to the GI removal circuit 208, and the scramble code reception timing is output to the scramble code identification circuit 210.1 and the demodulation circuit 300.

After the scramble code reception timing detection circuit 200.2 detects the scramble code reception timing, the GI removal circuit 208 removes the GI, and FF
The T circuit 209 performs FFT, the scramble code identification circuit 210.1 specifies the scramble code number, and outputs it to the demodulation circuit 300 by the same circuit as in FIG. Further, the data demodulation processing by the demodulation circuit 300 is performed by the same circuit as in FIG.

A method of receiving a multi-carrier signal by the receiving device 20.2 having the above configuration will be described below. FIG. 15 is a flowchart showing a receiving process of a multicarrier signal by the receiving apparatus 20.2 shown in FIGS. 10 and 14. FFT is performed at a certain FFT timing (S2011.1), and F at a certain FFT timing is performed.
For the signal after FT, the correlation between the subcarrier component transmitting the synchronization signal and the synchronization signal replica is detected (S
2012.1). This is performed at a plurality of FFT timings (S201.1 to S201.m). All FF
With respect to the correlation value detected at the T timing, the scramble code reception timing is obtained at the timing at which the maximum correlation value is obtained. Further, the FFT timing is detected from the FFT timing at which the maximum correlation value is detected (S202).

Next, FFT is performed at the detected FFT timing (S203), and the received signal is separated into each subcarrier component. At the reception timing of the detected scramble code, the correlation between the received signal separated into each subcarrier component after FFT and each scramble code is detected (S204), and the scramble code having the maximum correlation value is received. It is detected as a scramble code to be spread (S205).

Subsequently, the demodulation circuit 300 in the receiving apparatus 20.2 descrambles the multicarrier signal using the scramble code thus detected, and further demodulates and decodes the data signal to take out the original data sequence. is there.

Next, a receiving apparatus according to the fifth embodiment of the present invention will be described with reference to FIGS. 16 and 12. Fourth
The receiving device 20.3 according to the embodiment is composed of a scramble code reception timing detection circuit 200.3, a scramble code identification circuit 210.1, and a demodulation circuit 300.

The scramble code reception timing detection circuit 200.3 receives the multi-carrier signal and outputs the DFT.
A circuit or the like 2011 is used to separate each subcarrier component. Of the separated subcarrier components, only the subcarrier component in which the synchronization channel is multiplexed is correlated 20
Enter in 12. On the other hand, the synchronization signal replica generator 201
3 generates a synchronization signal replica and inputs it to the correlator 2012. The correlator 2012 detects the correlation between each subcarrier component from the DFT circuit 2011 and the synchronization signal replica, and adds the correlation value in each subcarrier to the adder 2
Enter in 07. The adder 207 adds the correlation values in each subcarrier, and stores the correlation value and its timing in the correlation value and timing memory 203. The timing detection circuit 204 selects the maximum correlation value and the timing from the stored values of the correlation value and the timing in the memory 230, and stores them in the memory 205 as the scramble code reception timing. The scramble code reception timing of the scramble code reception circuit 210.
Output to.

The scramble identification circuit 210.1 has the same configuration as that of FIG. The scramble code replica generator 211 sets a plurality of types of phases set in advance by a predetermined calculation to the synchronization phase obtained from the scramble code reception timing detection circuit 200.3. The correlator 212 for the number of subcarriers detects the correlation between the scramble code replica generated by the scramble code replica generator 211 and the output of the DFT circuit 2011 for each subcarrier, and adds the correlation detection value to the adder 21.
Input to 3. The adder 213 adds the correlation values for each subcarrier and stores the correlation value and its scramble code number in the memory 214 for the correlation value and code number.
The scramble code detection circuit 215 selects the maximum correlation value and the code number from the stored values of the correlation value and the code number in the memory 214, and outputs the identified scramble code number to the demodulation circuit 300. The data demodulation processing by the demodulation circuit 300 is performed by the circuit of FIG. 12 described above.

A method of receiving a multi-carrier signal by the receiver 20.3 in the MC-CDMA mobile communication system having the above configuration will be described below. FIG. 17
3 is a flowchart showing a method of receiving a multi-carrier signal by the receiving device 20.3. First, DF
The received signal is separated into subcarrier components using a T (Discrete Fourier Transform) circuit or the like (S301).
Of the received signals separated into the subcarrier components, the correlation between the subcarrier component transmitting the synchronization signal and the synchronization signal is detected (S302), and the reception timing of the scramble code is determined by the timing of obtaining the maximum correlation value. Obtain (S303).

Next, at the reception timing of the detected scramble code, the correlation between the received signal separated into each subcarrier component and each scramble code is detected (S304), and the scramble code having the maximum correlation value is detected. The received signal is detected as a scramble code for spreading (S305).

Demodulation circuit 300 in receiver 20.3.
Uses the scramble code thus detected to descramble the multi-carrier signal, demodulates and decodes the data signal, and extracts the original data sequence.

Next, a multicarrier signal receiving apparatus according to the sixth embodiment of the present invention will be described with reference to FIGS. 18 and 12. This receiving device 20.4 has m scramble code correlation detecting circuits 230.1 to 230.1 shown in FIG.
230. m, FF that sets FFT timing to these
T timing setting circuit 2014 and scramble code and scramble code reception timing detection circuit 24
0, and the demodulation circuit 300 shown in FIG. Each scramble correlation detection circuit 230. x is GI
It includes a removal circuit 205, an FFT circuit 2016, a scramble code reception timing detection circuit 200.3 similar to that provided in FIG. 16, and a scramble code identification circuit 210.2.

Each scramble code correlation detection circuit 23
0. x inputs the multicarrier signal received by the antenna 199. On the other hand, the FFT timing setting circuit 20
14 is a scrambling code correlation detection circuit 230. x
The FFT timing is set for the GI removing circuit 2015. The GI removing circuit 2015 removes GI using the set FFT timing. The multicarrier signal from which the GI has been removed is input to the FFT circuit 2016, separated into each subcarrier component, and only the subcarrier component is input to the correlator 2012. On the other hand, the synchronization signal replica generator 2013 generates the synchronization signal replica, and the correlator 20
Enter in 12. The correlator 2012 detects the correlation between each subcarrier component from the FFT circuit 2016 and the synchronization signal replica, and inputs the correlation value in each subcarrier to the adder 207. The adder 207 adds the correlation values in each subcarrier, and stores the correlation value and its timing in the correlation value and timing memory 203.

The timing detection circuit 204 selects the maximum correlation value and timing from the stored values of the correlation value and timing in the memory 203, and stores them in the memory 205 as scramble code reception timing candidates.

After detecting the scramble code reception timing, the scramble code identifying circuit 210.2.
The phase of the scramble code replica generator 211 is set to the synchronous phase obtained from the scramble code reception timing detection circuit 200.3. In the correlator 212,
The correlation between the scramble code replica generated by the scramble code replica generator 211 and the output of the FFT circuit 2016 is detected for each subcarrier, and the correlation detection value is input to the adder 213. The adder 213 adds the correlation values for each subcarrier and stores the correlation value and its scramble code number in the memory 214 for the correlation value and code number.

In the scramble code and scramble code reception timing detection circuit 240, the maximum correlation value and code number are selected from the correlation value in each scramble code identification circuit 210.2 and the stored value of the code number in the memory 214. Memory 205 in scramble code reception timing detection circuit 200.3 when maximum correlation value is detected
The scramble code reception timing is selected from the stored value of. The selected scramble code number and scramble code reception timing are output to the demodulation circuit 300.

A method of receiving a multi-carrier signal by the receiver 20.4 in the MC-CDMA mobile communication system having the above configuration will be described below. FIG. 19
3 is a flowchart showing a method of receiving a multicarrier signal by the receiving device 20.4. FFT is performed at a certain FFT timing (S4011.1), and the signal after the FFT at a certain FFT timing is
The correlation between the subcarrier component transmitting the synchronization signal and the synchronization signal is detected (S4012.1). The timing at which the maximum correlation value is obtained is detected at each FFT timing, and this is set as a scramble code reception timing candidate at the FFT timing (S4013.1). Then, at this scramble code reception timing, the correlation between the received signal separated into each subcarrier component and each scramble code is detected (S4014.1). This is performed at a plurality of FFT timings (S401.1 to S4).
01. n).

Next, among the correlation values of the scramble code detected at all the FFT timings, the scramble code having the maximum correlation value and its timing detect the scramble code for spreading the received signal and its reception timing (S402). . The demodulation circuit 300 descrambles the multi-carrier signal using the scramble code thus detected, and further demodulates and decodes the data signal to extract the original data sequence.

Next, MC- of the seventh embodiment of the present invention
A receiving device used in the CDMA transmission system will be described with reference to FIGS. 20 and 12. The receiving device 20.5 according to this embodiment includes an FFT timing detection circuit 250.1, G
I removal circuit 2015, FFT circuit 2016, scramble code reception timing detection circuit 200.3 similar to that shown in FIG. 16, and scramble code identification circuit 210.1 similar to that shown in FIG. 14, and FIG.
The demodulation circuit 300 shown in FIG.

The receiving device 20.5 inputs the multi-carrier signal received by the antenna 199 to the FFT timing detecting circuit 250.1, the GI removing circuit 2015 and the demodulating circuit 300, respectively. FFT timing detection circuit 250.
In No. 1, the delay circuit 251 delays the received multicarrier signal by one symbol length (excluding GI). The multiplier 252 multiplies the received multicarrier signal by a signal obtained by delaying the received signal by one symbol length (excluding GI). The multiplied signal is integrated over the GI length in the integrator 253, and the correlation value is detected. The detected correlation value and its timing are stored in the correlation value and timing memory 254. The timing detection circuit 255 selects the maximum correlation value and the timing from the stored values of the correlation value and the timing in the memory 254, and stores them in the memory 256 as the FFT timing.

After detecting the FFT timing, the GI removing circuit 2015 removes the GI from the multi-carrier signal using the FFT timing output from the memory 256. The multicarrier signal from which the GI has been removed is input to the FFT circuit 2016 and separated into each subcarrier component.

Of the signals separated into each subcarrier component, only the subcarrier component in which the synchronization channel is multiplexed is scramble code reception timing detection circuit 20.
Input to each correlator 2012 of 0.3. The processing in this scramble code reception timing detection circuit 200.3 is the same as that in FIG. Then, the detected scramble code reception timing is stored in the memory 205.

After detecting the scramble code reception timing, the scramble code identifying circuit 210.
Identify the scramble code number. The processing by this scramble code identification circuit 210.1 is the same as that of FIG. Then, the scramble code detection circuit 2
The scramble code number output by 15 is the demodulation circuit 3
00 is input.

The demodulation circuit 300 is the one shown in FIG. 12, and as described above, descrambles the multicarrier signal using the scramble code number,
Further, the data signal is demodulated and decoded to take out the original data series.

A method of receiving a multi-carrier signal by the receiver 20.5 in the MC-CDMA mobile communication system having the above configuration will be described below. Figure 21
3 is a flowchart showing a method of receiving a multicarrier signal by the receiving device 20.5. First, FF
The correlation between the received signal including all subcarrier components before performing T and the signal obtained by delaying the received signal by one symbol length (excluding the guard interval) is detected (S501).
The FFT timing is obtained from the timing at which the maximum correlation value is obtained (S502).

Next, FFT is performed at the detected FFT timing to separate the received signal into subcarrier components (S503). Of the received signals separated into each subcarrier component, the correlation between the subcarrier component transmitting the synchronization signal and the synchronization signal is detected (S504), and the timing of obtaining the maximum correlation value determines the reception timing of the scramble code. Ask (S505). Then, the scramble code for spreading the received signal is detected by the same method as steps S304 and S305 in the flowchart of FIG.

Using the scramble code thus obtained, in the demodulation circuit 300 as in the other embodiments, the multicarrier signal is descrambled, and the data signal is demodulated and decoded to obtain the original data. Take out the series.

Next, MC- of the eighth embodiment of the present invention
A receiving device in a CDMA mobile communication system will be described. The circuit of FIG. 20 and the MC-CDMA signal reception technique shown in the flowchart of FIG. 21 detect one FFT timing from the timing at which the maximum correlation value is obtained by using the correlation characteristic of the guard interval.

However, in the MC-CDMA mobile communication system, in a situation where signals are simultaneously transmitted from a plurality of base stations and they are simultaneously received by one mobile station, the total transmission power between the base stations may vary. For example, the mobile station is not the signal from the optimal base station with a small amount of received signal attenuation,
A signal from a base station with a large total transmission power may be erroneously detected as a regular signal. The above problem is illustrated as follows.

The flowchart of FIG. 22 shows the correlation detection processing procedure of the guard interval part by the receiver of FIG. 20, and FIG. 23 shows the method principle. Here, the FFT timing is the timing at which the head of the information symbol that does not include the guard interval is received, and is the timing at which the FFT processing should be performed. Therefore, in the following description, all FFT timings are FF.
T timing. Further, it is assumed that 1 symbol length = X samples and guard interval length = Y samples.

In the flowchart of FIG. 22 and the receiving method shown in FIG. 23, the received signal including all subcarrier components before FFT and the received signal are 1 symbol (X samples).
The long-delayed signal is multiplied at each sample timing (step S1001). Then, the multiplication value for each sample timing is subjected to a moving average for each sample with each sample timing being the start of the average section and the average section length being the Y sample length (step S1002). The series of correlation values obtained by the moving average is averaged a plurality of times by in-phase addition for each (X + Y) sample to obtain a correlation series of (X + Y) sample length (step S1003). FIG. 24 shows an example of this correlation sequence. Then, as shown in FIG.
+ Y) The timing at which the maximum correlation value is obtained in the correlation series of sample length is detected as the FFT timing (step S1004).

However, the magnitude of the correlation peak as in the correlation sequence shown in FIG. 24 depends not only on the attenuation amount of the received signal (path loss due to distance attenuation or shadowing) but also on the total transmission power of each base station. Dependent. Therefore, when the above-described method is used in a mobile communication system of the MC-CDMA system, in a multi-cell environment, when the total transmission power of each base station varies, the maximum reception level per channel (minimum path loss) There is a possibility that a base station with a large power of the communication channel being transmitted may be erroneously detected instead of the optimum base station of). For example, base stations # 1 and #
2 and the number of communication channels of the base station # 1 is significantly smaller than the number of communication channels of the base station # 2, the number of communication channels is large even if the most suitable base station for the mobile station is the base station # 1. Therefore, base station # 2 having a large total transmission power
May be erroneously detected.

FIG. 25 shows a receiver in a mobile communication system of MC-CDMA system which solves this problem. The receiver 20.6 of FIG. 25 has an FFT timing detection circuit 250.2 and a scramble code correlation detection circuit 23.
0.1-230. m, scramble code and scramble code reception timing detection circuit 240, and FIG.
The demodulation circuit 300 is the same as that shown in FIG.

The FFT timing detection circuit 250.2 is
The delay circuit 251 delays the received multicarrier signal by one symbol length (excluding GI). Multiplier 2
52 multiplies the received multi-carrier signal by the signal delayed by one symbol length (excluding GI). The multiplied signal is integrated over the GI length in the integrator 253, and the correlation value is detected. The detected correlation value and its timing are stored in the correlation value and timing memory 254.

In the timing detection circuit 255, first,
The maximum correlation value and the timing are selected from the stored values of the correlation value and the timing in the memory 254 and stored in the memory 256 as the FFT timing candidate # 1. Next, in the search range setting circuit 257, the search range is set based on the detected FFT timing candidates and correlation values in the memory 256 and the stored values in the timing memory 254. Various methods described later are used to set the search range. The timing detection circuit 255 selects the maximum correlation value and timing from the stored values of the correlation value and timing in the memory 254 within the search range set by the search range setting circuit 257, and selects the FFT timing candidate # 2.
Is stored in the memory 256 as In the same procedure, detection is continued until a plurality of arbitrary preset FFT timing candidates are detected.

Scramble code correlation detection circuit 230.
1 to 230 m are prepared for the number m of FFT timing candidates detected by the FFT timing detection circuit 250.2.
Each scramble code correlation detection circuit 230. x (x = 1
~ M) is the same as that shown in FIG.
A removal circuit 2015, an FFT circuit 2016, a scramble code reception timing detection circuit 200.3, and a scramble code identification circuit 210.2.

Each scramble code correlation detection circuit 23
0. The x inputs the multicarrier signal received by the antenna 199 to the GI removal circuit 2015. On the other hand, FFT
The timing detection circuit 250.1 includes the scramble code correlation detection circuits 230. The FFT timing is set for the GI removal circuit 2015 of x.

The GI removing circuit 2015 is configured to set the FF.
Remove GI using T timing. The multicarrier signal from which the GI has been removed is input to the FFT circuit 2016, separated into each subcarrier component, and only the subcarrier component is input to the correlator 2012. On the other hand, the synchronization signal replica generator 2013 generates a synchronization signal replica and inputs it to the correlator 2012. In the correlator 2012, FF
The correlation between each subcarrier component from the T circuit 2016 and the synchronization signal replica is detected, and the correlation value in each subcarrier is input to the adder 207. The adder 207 adds the correlation values in each subcarrier, and stores the correlation value and its timing in the correlation value and timing memory 203. The timing detection circuit 204 selects the maximum correlation value and timing from the stored values of the correlation value and timing in the memory 203, and stores them in the memory 205 as scramble code reception timing candidates. Therefore, m scramble code correlation detection circuits 230.1 to 230. m
Thus, m scrambling code reception timing candidates are obtained.

After detecting each scramble code reception timing candidate, the scramble code identification circuit 210.2 obtains a scramble code number and a correlation value corresponding to each scramble code reception timing candidate.

The scramble code and scramble code reception timing detection circuit 240 selects the maximum correlation value and code number from the correlation value of each scramble code identification circuit 210.2 and the stored value of the code number memory 214. When the maximum correlation value is detected, the corresponding memory 2 in the scramble code reception timing detection circuit 200.3
The scramble code reception timing candidate is selected from the stored values of 05 and used as the scramble code reception timing. Then, the selected scramble code number and the scramble code reception timing are output to the demodulation circuit 300.

The demodulation circuit 300 is the one shown in FIG. 12, and as described above, descrambles the multicarrier signal using the scramble code number,
Further, the data signal is demodulated and decoded to take out the original data series.

F in the receiver 20.6 having the above configuration
A method of detecting a predetermined number of FFT timing candidates from the received multicarrier signal by the FT timing detection circuit 250.2 will be described with reference to the flowchart of FIG.

The received multicarrier signal including all subcarrier components before FFT and the signal obtained by delaying the received multicarrier signal by one symbol (X samples) are multiplied at each sample timing (step S110).
1). Then, the multiplication value for each sample timing is subjected to a moving average for each sample, with each sample timing being the start of the average section and the average section length being the Y sample length (step S1102). The correlation value sequence obtained by the moving average is averaged multiple times by in-phase addition for each (X + Y) sample to obtain a correlation sequence of (X + Y) sample length (step S1103). The above-described processing of S1101 to S1103 is performed by S1001 to S1 in the flowchart of FIG.
This is similar to the processing of 003.

Then, as shown in FIG. 24, (X + Y)
A plurality of FFT timing candidates are detected from the sample length correlation sequence (steps S1104 to S1106). Figure 2
7 shows a case where three FFT timing candidates are detected. This is detected as follows. First,
The timing at which the maximum correlation output is detected in the correlation sequence of (X + Y) sample length is set as the FFT timing candidate # 1. Next, the preset W samples around the FFT timing candidate # 1 are excluded from the search range as the exclusion window # 1, and the timing at which the maximum correlation output is detected in the correlation sequence of (X + Y−W) sample length is the FFT timing. Candidate # 2. Similarly, the W samples around the FFT timing candidate # 2 are further excluded from the search range as the exclusion window # 2, and the FFT timing candidate # 3 is detected.

By using the above method, even when the total transmission power of each base station varies in a multi-cell environment, it is possible to detect a base station having a small total transmission power without overlooking.

In this way, the scramble code is identified by the flow chart shown in FIG. 28 using the predetermined number m of detected FFT timing candidates. The processing shown in FIG. 28 is an example in the case where the number of scramble code reception timing candidates to be detected is equal to the number m of FFT window timing candidates.

The process S1100 for detecting a plurality of m FFT timing candidates is the entire process shown in the flowchart of FIG.

Following this, FFT is performed on the detected plurality of FFT timing candidates, and the correlation between the subcarrier component transmitting the synchronization signal and the synchronization signal is detected for the signal after each FFT (step S1201. 1,
S1202.1). Then, the timing at which the maximum correlation value is detected in each FFT timing candidate is set to the FFT
A scramble code reception timing candidate at the timing is set, and the correlation between the received signal separated into each subcarrier component and each scramble code is detected in the scramble code reception timing candidate (step S
1203.1, S1204.1). This step S12
The processing of 01.1 to S1204.1 is performed for all FFT timing candidates of a plurality of m (S1200.1 to S1200.1).
1200. m).

Next, among the correlation values of the scramble codes detected in all the FFT timing candidates, the scramble code having the maximum correlation value and its timing are used to detect the scramble code for spreading the received signal, its reception timing and FFT timing. Yes (S1
300). That is, the FFT timing and the scramble code reception timing are determined at the same time as the scramble code type in step S1300.

The method for detecting a plurality of m FFT timing candidates performed by the FFT timing detection circuit 250.2 in the receiving apparatus shown in FIG. 25 may be that shown in FIG. 29 or 30. FIG. 29 shows exclusion windows # 1 and #.
This is the case where 2 do not overlap. FFT timing candidate # 1
After the detection, the FFT timing candidate # 1 is set as the front and rear W / 2 samples, and the W samples are set as the exclusion window # 1. W samples are excluded from the search range, and the timing at which the maximum correlation output is detected in the correlation sequence of (X + Y−W) sample length is set as FFT timing candidate # 2. Similarly, the peripheral W samples of the FFT timing candidate # 2 are excluded from the search range as the exclusion window # 2, and the FFT timing candidate # 3 is detected.

FIG. 30 shows the case where the exclusion window # 1 and the exclusion window # 2 overlap. By the same method as in FIG. 29, up to FFT timing candidate # 2 is detected. F
The peripheral W samples of the FT timing candidate # 2 are excluded from the search range as the exclusion window # 2, but since there is a portion where the exclusion windows # 1 and # 2 overlap, the number of samples excluded from the search range is less than 2W samples. Become.

Next, another method of determining a plurality of FFT timing candidates will be described with reference to FIG. When three FFT timing candidates (m = 3) are detected, after detecting FFT timing candidate # 1, FFT timing candidate # is detected.
The W samples up to the timing having the correlation value of ΔdB less than the correlation value of 1 are set as the exclusion window # 1. Then, the exclusion window for the W samples is excluded from the search range, and the timing at which the maximum correlation output is detected in the correlation sequence having the (X + Y−W) sample length is set as the FFT timing candidate # 2. In the same procedure, W ′ samples up to the timing having a correlation value of ΔdB less than the correlation value in FFT timing candidate # 2 are set as exclusion window # 2, W ′ samples are further excluded from the search range, and FFT timing candidates are set. Detect # 3.

Next, referring to FIGS. 32 and 33, a plurality of F
Yet another method for determining FT timing candidates is described. Also in this case, the case where three (m = 3) FFT timing candidates are detected is shown as an example. Figure 32 shows FFT
This is a case where the window width is changed depending on the size of the slope of the correlation sequence having the timing as the apex. When the slope of the correlation peak is steep, the exclusion window is set narrow, and when the slope is gentle, the exclusion window is set wide. That is, when the peak width is narrow, the width is set narrow as shown in the exclusion window # 1, and when the peak width is wide, the width is set wide as shown in the exclusion window # 2.

FIG. 33 shows an example of setting as an exclusion window while the correlation value continues to decrease with increasing distance from the detected FFT timing (the peak of the correlation peak). In this case, after detecting the FFT timing candidate # 1, the W samples whose correlation value continues to decrease as the FFT timing candidate # 1 moves away are excluded from the search range as the exclusion window # 1. Then, the timing at which the maximum correlation output is detected in the correlation sequence of (X + Y−W) sample length is set as the FFT timing candidate # 2. By the same procedure, W'samples whose correlation value continues to decrease as the distance from this FFT timing candidate # 2 is excluded from the search range as an exclusion window # 2, and the next FFT timing candidate # 3 is detected.

According to the method shown in FIGS. 32 and 33,
Even when the correlation peaks overlap or the peak width changes due to the influence of multipath, the exclusion window can be adaptively set.

Next, referring to FIGS. 34 and 35, a plurality of F
Yet another method for determining FT timing candidates is described. FIG. 34 shows a method of detecting two FFT timing candidates by any of the methods of FIGS. 27 to 5.2 described above and further adding eight FFT timing candidates. First, two FFT timing candidates # 1 and # 2 are detected by the above method. Then, the timings of ± A samples and ± 2A samples of the FFT timing candidates # 1 and # 2 are also set as FFT timing candidates.

FIG. 35 shows a method of detecting two FFT timing candidates by any of the methods shown in FIGS. 27 to 5.2 and adding four new FFT timing candidates. First, two FFT timing candidates # 1 and # 2 are detected by the above method. Then, the timing having the correlation value of ΔdB less than the correlation value in the FFT timing candidates # 1 and # 2 is set as the FFT timing candidate.

According to the above method, even if the correlation peaks are overlapped and the timing is detected with a large shift from the ideal timing, or even if the timing is detected with a shift due to the influence of noise or interference, the shift amount is changed. Can be suppressed to a small value, and the FFT timing can be detected with higher accuracy.

Even if a plurality of m FFT timing candidates are detected by any of these methods, the FFT timing candidates are detected.
The process of detecting the scramble code number and the reception timing using the timing candidate is performed by the processes S1200 and S1300 of FIG. 28 described above.

Next, MC- of the ninth embodiment of the present invention
A receiver in the CDMA mobile communication system will be described with reference to FIG. The receiving apparatus 20.7 of this embodiment has the same FFT timing detection circuit 250.2 as that used in the receiving apparatus 20.6 of FIG. scramble code reception timing detection circuit 200.2, G similar to that used for x
The I removing circuit 208, the FFT circuit 209, the scramble identifying circuit 210. 1 and the demodulating circuit 300 same as that shown in FIG.

The FFT timing detection circuit 250.2 detects a plurality of m FFT timing candidates from the received multi-carrier signal by the same processing as in FIG.

The scramble code reception timing detection circuit 200.2 is similar to that of FIG.
15, FFT circuit 2016, m synchronization signal correlation detection circuits 2011.about.2010. m, a timing detection circuit 204, and a memory 205.

The scramble code reception timing detection circuit 200.2 receives a multi-carrier signal and outputs a plurality of m sync signal correlation detection circuits 2011.about.2010.
Input to m. On the other hand, the FFT timing detection circuit 25
0.2 is a synchronization signal correlation detection circuit 2010. x (x =
1, 2, ..., M), FFT timing candidates are set.

Each sync signal correlation detection circuit 2010. At x, the guard interval removal circuit 2015 causes each F
G from multi-carrier signals using FT timing candidates
Remove I. The GI-removed multicarrier signal is input to the FFT circuit 2016, and is separated by the FFT circuit 2016 into a plurality of subcarrier components in which the synchronization channels are multiplexed. Of the separated subcarrier components, only the subcarrier component in which the synchronization channel is multiplexed is input to the correlator 2012. On the other hand, the synchronization signal replica generator 2013 generates a synchronization signal replica and inputs it to the correlator 2012. The correlator 2012 detects the correlation between the FFT output and the synchronization signal replica, and inputs the correlation value in each subcarrier to the adder 207. Adder 2
In 07, the correlation value in each subcarrier is added and the correlation value and its timing are stored in the memory 2 of the correlation value and the timing.
Store in 03.

The timing detection circuit 204 selects the maximum correlation value and timing from the stored values of the m correlation values and the timing in the memory 203, and stores them in the memory 205 as the scramble code reception timing. The timing detection circuit 204 further calculates the FFT timing from the scramble code reception timing and stores it in the memory 205 as the FFT timing. The FFT timing is output from the memory 205 to the GI removal circuit 208, and the scramble code reception timing is output to the scramble code identification circuit 210.1 and the demodulation circuit 300.

After the scramble code reception timing detection circuit 200.2 detects the scramble code reception timing, the GI removal circuit 208 removes the GI and FF
The T circuit 209 performs FFT, the scramble code identification circuit 210.1 specifies the scramble code number, and outputs it to the demodulation circuit 300 by the same circuit as in FIG. The demodulation circuit 300 shown in FIG. 12 performs descrambling on the multicarrier signal using the scramble code number as described above, and further demodulates and decodes the data signal to take out the original data sequence.

The method of detecting the scramble code number and the timing by the receiving apparatus 20.7 having the above configuration is shown in FIG.
According to the flowchart of 7. First, the FFT timing detection circuit 250.2 detects a predetermined number m of FFT timing candidates from the received multi-carrier signal (S1100). This process is based on the flowchart of FIG. 26, as in the eighth embodiment. In addition, multiple FFs
The detection of the T timing candidate may be performed by any of the methods shown in FIGS. 27 to 35 described above.

Next, FFT is performed on the detected plurality of FFT timing candidates, and the signal after each FFT is
The correlation between the subcarrier component transmitting the synchronization signal and the synchronization signal is detected (S1401.1, S1402.
1). This is performed for all FFT timing candidates (S1400.1 to S1400.m).

Next, of the correlation values in all the FFT timing candidates, the timing at which the maximum correlation value is detected and the FFT timing at that time are the reception timing of the scramble code for spreading the reception signal and the FFT timing of the reception signal. (Step S1500). Next, at the detected scramble code reception timing, the correlation between the received signal separated into each subcarrier component and each scramble code is detected (step S160).
0). Then, a scramble code for spreading the received signal is detected from the scramble code having the maximum correlation value (step S1700).

In the method shown in the flowchart of FIG. 37, the FFT timing and the scramble code reception timing are determined in step S1500 before the scramble code type is detected.

Next, a scramble code correlation detection method will be described. However, the subcarrier frequency is # 1
It is assumed that there are N pieces of #N. In the example (tenth embodiment) shown in FIG. 38, Navg = 6, Ncs = 4, Nps = N / N
This is an example in the case of cs. The correlation value of each symbol is added in Navg symbol in-phase in the time direction for each subcarrier. Then, the in-phase addition value for each subcarrier is added in-phase over the Ncs subcarriers. Then, Nps pieces of power are added to the in-phase addition value for each Ncs subcarrier in the frequency direction,
The correlation value of each scramble code is calculated.

When Nps = N / Ncs as in this example, 1 using N subcarriers × Navg symbols
The correlation value for the scramble code will be detected.

Example shown in FIG. 39 (eleventh embodiment)
Is an example in the case of Navg = 6, Ncs = 4, Nps = 1. In this case, since Nps = 1, the in-phase addition value of Ncs subcarriers becomes the correlation value of each scramble code, and N subcarriers × Navg symbols gives N / N.
The correlation value of Ncs scramble codes is detected.

Next, the example shown in FIG. 40 (the twelfth embodiment) is an example in the case of Nps = (N / Ncs) / 4. The correlation of (N / Ncs) / Nps = 4 scramble codes is alternately detected for each Ncs subcarrier. Then, the correlation value of each scramble code can be detected by adding Nps powers of the in-phase added value for each Ncs subcarrier in the frequency direction for each code.

As in this example, Nps = (N / Ncs) /
In the case of 4, the correlation value for 4 scramble codes is detected using N subcarriers × Navg symbols.

Further, the example shown in FIG. 41 (thirteenth embodiment) is an example in the case of Nps = (N / Ncs) / 2. In this case, the correlation value for two scramble codes can be detected using N subcarriers × Navg symbols.

[0142]

According to the present invention, in the MC-CDMA system using a scramble code, high speed and highly accurate spread code synchronization is possible.

Further, according to the present invention, in a mobile communication system using the MC-CDMA system, even if the total transmission power varies among cells in a multi-cell environment, by providing a plurality of candidates, the optimum cell can be selected. FFT
The timing can be detected.

[Brief description of drawings]

FIG. 1 is a block diagram of a transmission device in a conventional MC-CDMA mobile communication system.

FIG. 2 is a diagram showing a scramble code pattern in the above conventional example.

FIG. 3 is a block diagram of a transmission device according to the first embodiment of this invention.

FIG. 4 is a diagram showing a structure of a synchronization signal in the transmission device according to the first embodiment of the present invention.

FIG. 5 is a diagram showing the configuration of another synchronization signal in the transmission device according to the first embodiment of the present invention.

FIG. 6 is a diagram showing the configuration of still another synchronization signal in the transmission device according to the first embodiment of the present invention.

FIG. 7 is a diagram showing the configuration of still another synchronization signal in the transmission device according to the first embodiment of the present invention, and a diagram showing the synchronization signal timing thereof.

FIG. 8 is a block diagram of a transmission device according to a second embodiment of this invention.

FIG. 9 is a diagram showing a structure of a synchronization signal in a transmission device according to a second embodiment of the present invention.

FIG. 10 is an MC-CDMA according to a third embodiment of the present invention.
It is a block diagram of a receiver of the system.

FIG. 11 is a block diagram showing a detailed configuration of a scramble code reception timing detection circuit and a scramble code identification circuit in the receiving apparatus according to the third embodiment of the present invention.

FIG. 12 is a block diagram showing a detailed configuration of a demodulation circuit in a receiving device according to a third embodiment of the present invention.

FIG. 13 is a flowchart showing a method of receiving a multicarrier signal by the receiving device according to the third embodiment of the present invention.

FIG. 14 is an MC-CDMA according to a fourth embodiment of the present invention.
It is a block diagram of a receiver of the system.

FIG. 15 is a flowchart showing a method of receiving a multicarrier signal by the receiving device according to the fourth embodiment of the present invention.

FIG. 16 is an MC-CDMA according to a fifth embodiment of the present invention.
It is a block diagram of a receiver of the system.

FIG. 17 is a flowchart showing a method of receiving a multicarrier signal by the receiving device according to the fifth embodiment of the present invention.

FIG. 18 is MC-CDMA according to the sixth embodiment of the present invention.
It is a block diagram of a receiver of the system.

FIG. 19 is a flowchart showing a method of receiving a multi-carrier signal by the receiving device according to the sixth embodiment of the present invention.

FIG. 20 is MC-CDMA according to a seventh embodiment of the present invention.
It is a block diagram of a receiver of the system.

FIG. 21 is a flowchart showing a method of receiving a multi-carrier signal by a receiving device according to a seventh embodiment of the present invention.

FIG. 22 is a flowchart showing a process of detecting FFT timing from a received signal in a general MC-CDMA system.

FIG. 23 is an explanatory diagram of the FFT timing detection process shown in FIG. 22.

FIG. 24 is a correlation sequence diagram of detected FFT timing.

FIG. 25 is an MC-CDMA according to an eighth embodiment of the present invention.
It is a block diagram of a receiver of the system.

FIG. 26 is a flowchart showing a signal receiving method by the receiving device according to the eighth embodiment of the present invention.

FIG. 27 is an explanatory diagram showing FFT timing candidates determined by a signal receiving method by the receiving device according to the eighth embodiment of the present invention.

FIG. 28 is a flowchart showing a signal receiving method by the receiving device according to the seventh embodiment of the present invention.

FIG. 29 is an explanatory diagram showing another FFT timing candidate detection method by the receiving device according to the eighth embodiment of the present invention.

FIG. 30 is an explanatory diagram showing still another FFT timing candidate detection method by the receiving device according to the eighth embodiment of the present invention.

FIG. 31 is an explanatory diagram showing still another FFT timing candidate detection method by the receiving device according to the eighth embodiment of the present invention.

FIG. 32 is an explanatory diagram showing still another FFT timing candidate detection method by the receiving device according to the eighth embodiment of the present invention.

FIG. 33 is an explanatory diagram showing still another FFT timing candidate detection method by the receiving device according to the eighth embodiment of the present invention.

FIG. 34 is an explanatory diagram showing still another FFT timing candidate detection method by the receiving device according to the eighth embodiment of the present invention.

FIG. 35 is an explanatory diagram showing still another FFT timing candidate detection method by the receiving device according to the eighth embodiment of the present invention.

FIG. 36 is an MC-CDMA according to the ninth embodiment of the present invention.
It is a block diagram of a receiver of the system.

FIG. 37 is a flowchart showing a signal receiving method by the receiving device according to the seventh embodiment of the present invention.

[Fig. 38] Fig. 38 is a diagram illustrating a method for detecting correlation of a long-period spreading code by a receiving device according to a tenth embodiment of the present invention.

[Fig. 39] Fig. 39 is a diagram illustrating a correlation detection method for a long-period spreading code by a receiving device according to an eleventh embodiment of the present invention.

[Fig. 40] Fig. 40 is a diagram showing a correlation detection method for long-period spreading codes by the receiving device according to the twelfth embodiment of the present invention.

[Fig. 41] Fig. 41 is a diagram illustrating a method for detecting correlation of a long-period spreading code by a receiving device according to a thirteenth embodiment of the present invention.

[Explanation of symbols]

10 transmitter 100 data channel generator 101 transmission data generator 107 short-cycle spreading code generator 108 multiplier 109 first combiner 110 scramble code generator 111 multiplier 112 second combiner 113 IFFT circuit 114 guard interval insertion Device 120 Synchronous signal generator 121 Data generator 123 Spreading code generator for synchronous signal 124 Multiplier 125 Serial-parallel converter 126 Multiplier 199 Antenna 20 Receiver 200 Scrambling code reception timing detection circuit 201 Correlator 202 Synchronous signal replica generator 203 memory of correlation value and timing 204 timing detection circuit 205 memory 207 adder 208 guard interval removal circuit 209 FFT circuit 210 scramble code identification circuit 211 scramble code replica generator 12 Correlator 213 Adder 214 Memory of correlation value and code number 215 Scramble code detection circuit 2010 Sync signal correlation detection circuit 2012 Correlator 2013 Sync signal replica generator 2014 FFT timing setting circuit 2015 Guard interval removal circuit 2016 FFT circuit 230 Scramble code Correlation detection circuit 240 Scramble code and scramble code reception timing detection circuit 250 FFT timing detection circuit 251 Delay circuit 252 Multiplier 253 Integrator 254 Correlation value and timing memory 255 Timing detection circuit 256 Memory 300 Demodulation circuit 301 Scramble code generator 302 FFT Timing detection unit 303 Guard interval removal circuit 304 FFT circuit 305 Channel estimation unit 309 Sheet code generator 3 10 adder 312 data demodulator 313 decoder

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mamoru Sawahashi             2-11-1, Nagatacho, Chiyoda-ku, Tokyo Stock             Ceremony company NTT Docomo F term (reference) 5K022 AA10 AA16 AA26 EE02 EE13                       EE22 EE32 EE36                 5K047 AA02 BB01 GG34 HH15 MM02                       MM12 MM24 MM38                 5K067 CC10 DD19 DD25 EE10 GG02                       HH21 HH36

Claims (36)

[Claims] 1. A short-cycle spreading code multiplication unit for multiplying each of a plurality of transmission data sequences by a plurality of short-cycle spreading codes, and a short-cycle spreading code output from the short-cycle spreading code multiplication unit. A long-period spreading code multiplication unit that multiplies a long-period spreading code common to each of the multiplied transmission data sequences, and a synchronization that multiplies the synchronization-signal data by the synchronization-signal spreading code and outputs it. A signal generation unit, and each of the transmission data sequences in which the short-cycle spreading code and the long-cycle spreading code output from the long-cycle spreading code multiplication unit are doubly multiplied is transmitted using a plurality of subcarriers. And a transmission processing unit for transmitting, using one or a plurality of subcarriers, a synchronization signal obtained by multiplying the synchronization signal data output from the synchronization signal generation unit by only the synchronization signal spreading code. Career A transmitter in a CDMA mobile communication system. 2. The synchronization signal generator outputs the synchronization signal data by multiplying the synchronization signal data by a synchronization signal spreading code at a plurality of timings during a fixed period.
13. A transmitter in a mobile communication system of the multi-carrier CDMA system according to claim 1. 3. A synchronization signal obtained by multiplying a data sequence obtained by multiplying a short-period spreading code and a long-period spreading code by using a plurality of subcarriers, and multiplying only by a synchronization signal spreading code. Is transmitted by using one or a plurality of subcarriers. 4. The transmission method in a mobile communication system according to claim 3, wherein the synchronization signal is transmitted in a burst at known time intervals. 5. The synchronization signal represents the transmission timing of the long-cycle spreading code by a pattern of a code sequence of the spreading code for the synchronization signal.
A transmission method in the mobile communication system according to. 6. The transmission method in a mobile communication system according to claim 3, wherein the synchronization signal represents a transmission timing of the long-cycle spreading code according to a transmission timing. 7. The transmission method in a mobile communication system according to claim 3, wherein the synchronization signal represents a transmission timing of the long-period spreading code by a transmission timing and a subcarrier to be transmitted. 8. A multi-carrier CDMA for transmitting a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by using a plurality of subcarriers. And a signal receiving unit for receiving a multi-carrier signal including a synchronization signal in which only a synchronization signal spreading code is multiplied by one or a plurality of subcarriers, and the signal receiving unit. The multi-carrier signal received by,
A multi correlator that includes a correlator that obtains a correlation value with a synchronization signal replica, and a timing detector that detects an FFT timing and a reception timing of the long-period spreading code according to the correlation value obtained by the correlator. Carrier CD
Receiving device in MA mobile communication system. 9. A multi-carrier CDMA for transmitting a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in the long-cycle spreading code group by double using a plurality of subcarriers. And a signal receiving unit for receiving a multi-carrier signal including a synchronization signal in which only a synchronization signal spreading code is multiplied by one or a plurality of subcarriers, and the signal receiving unit. The multi-carrier signal received by,
A first correlator for obtaining a correlation value with the synchronization signal replica, and an FFT according to the correlation value obtained by the first correlator.
A timing detection unit that detects timing and a reception timing of the long-cycle spreading code; and an FFT that performs FFT according to the FFT timing detected by the timing detection unit and separates the multicarrier signal into a plurality of subcarrier components. Circuit, the plurality of subcarrier components separated by the FFT circuit according to the reception timing of the long-cycle spreading code detected by the timing detection unit, and each long-cycle spreading code included in the long-cycle spreading code group. A second correlator that obtains a correlation value between a code sequence and a code sequence obtained by multiplying the short-cycle spreading code by double, and the multi-carrier signal according to the correlation value obtained by the second correlator A code detection unit that detects a long-cycle spreading code that spreads, a reception timing of the long-cycle spreading code detected by the timing detection unit, and the code. A multi-carrier CDMA mobile communication system comprising a demodulation circuit that demodulates the data sequence from the multi-carrier signal received by the signal receiving unit using the long-cycle spreading code detected by the signal detection unit. Receiver. 10. Multi-carrier CDMA for transmitting a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by double, using a plurality of subcarriers. And a signal receiving unit for receiving a multi-carrier signal including a synchronization signal in which only a synchronization signal spreading code is multiplied by one or a plurality of subcarriers, and the signal receiving unit. The multi-carrier signal received by
A subcarrier separation unit that performs FFT according to a plurality of FFT timings and separates into a plurality of subcarrier components, and a subcarrier included in the synchronization signal among the plurality of subcarrier components separated by the subcarrier separation unit A correlator that obtains a correlation value between the component and the synchronization signal replica, and a timing detection unit that detects the reception timing and the FFT timing of the long-period spreading code according to the correlation value obtained by the correlator. Multi-carrier CDMA
Device in a mobile communication system of the above method. 11. A multi-carrier CDMA for transmitting a data sequence obtained by multiplying a short-period spreading code and any one long-period spreading code included in a long-period spreading code group by using a plurality of subcarriers. And a signal receiving unit for receiving a multi-carrier signal including a synchronization signal in which only a synchronization signal spreading code is multiplied by one or a plurality of subcarriers, and the signal receiving unit. The multi-carrier signal received by
A subcarrier separation unit that performs FFT according to a plurality of FFT timings and separates into a plurality of subcarrier components, and a subcarrier included in the synchronization signal among the plurality of subcarrier components separated by the subcarrier separation unit A first correlator that obtains a correlation value between the component and the synchronization signal replica; and timing detection that detects the reception timing and the FFT timing of the long-cycle spreading code according to the correlation value obtained by the first correlator. A FFT circuit that performs FFT according to the FFT timing detected by the timing detection unit and separates the multicarrier signal into a plurality of subcarrier components; and a long-cycle spreading code detected by the timing detection unit. A plurality of subcarrier components separated by the FFT circuit and the long-cycle spreading code group according to the reception timing. A second correlator that obtains a correlation value between each long-cycle spreading code and the short-cycle spreading code that are double-multiplied by each other, and the correlation value obtained by the second correlator. In accordance with the above, a code detection unit that detects a long-cycle spreading code that spreads the multi-carrier signal, a reception timing of the long-cycle spreading code detected by the timing detection unit, and the long-cycle spreading code detected by the code detection unit. And a demodulation circuit that demodulates the data sequence from the multi-carrier signal received by the signal receiving unit using a code and a receiving device in a multi-carrier CDMA mobile communication system. 12. A multi-carrier CDMA for transmitting a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by double using a plurality of subcarriers. And a signal receiving unit for receiving a multi-carrier signal including a synchronization signal in which only a synchronization signal spreading code is multiplied by one or a plurality of subcarriers, and the signal receiving unit. The multi-carrier signal received by
A subcarrier separation unit that separates into a plurality of subcarrier components, and a correlation that obtains a correlation value between a subcarrier component including the synchronization signal and a synchronization signal replica among the plurality of subcarrier components separated by the subcarrier separation unit And a timing detection unit that detects a reception timing of the long-period spreading code according to the correlation value obtained by the correlator, in a multicarrier CDMA mobile communication system. 13. A multi-carrier CDMA for transmitting a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by double, using a plurality of subcarriers. And a signal receiving unit for receiving a multi-carrier signal including a synchronization signal in which only a synchronization signal spreading code is multiplied by one or a plurality of subcarriers, and the signal receiving unit. The multi-carrier signal received by
A subcarrier separation unit that separates into a plurality of subcarrier components, and a correlation value between a subcarrier component including the synchronization signal and a synchronization signal replica among the plurality of subcarrier components separated by the subcarrier separation unit No. 1 correlator, a timing detection unit that detects a reception timing of the long-cycle spreading code according to the correlation value obtained by the first correlator, and the long-cycle spreading code detected by the timing detection unit. In accordance with the reception timing of the plurality of subcarrier components separated by the subcarrier separation unit, each long-cycle spreading code included in the long-cycle spreading code group, and the short-cycle spreading code are doubled. A second correlator that obtains a correlation value with the code sequence that has been multiplied; and a long-period spreading code that spreads the multicarrier signal according to the correlation value obtained by the second correlator. Code detection unit for detecting a signal, using the reception timing of the long-cycle spreading code detected by the timing detection unit and the long-cycle spreading code detected by the code detection unit, the signal receiving unit receives the A receiver in a multicarrier CDMA mobile communication system comprising a demodulation circuit for demodulating the data sequence from a multicarrier signal. 14. A multi-carrier CDMA for transmitting a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by double, using a plurality of subcarriers. A receiving device in a mobile communication system of a system, comprising: a receiving and receiving unit that receives a multicarrier signal including a synchronization signal in which only one or more subcarriers are multiplied by a synchronization signal spreading code; The multi-carrier signal received by
Among the plurality of subcarrier components separated by the subcarrier separation unit, which performs FFT according to each of the plurality of FFT timings and separates the plurality of subcarrier components into one set, A first correlator that obtains a correlation value between a subcarrier component including a synchronization signal and a synchronization signal replica for each of the plurality of sets, and the length depending on the plurality of correlation values obtained by the first correlator. A timing detection unit that detects a plurality of reception timing candidates of a cycle spreading code, and a plurality of subcarrier components and the plurality of subcarrier components according to the reception timing candidates of the plurality of long cycle spreading codes detected by the timing detection unit, respectively. The correlation value between each long-cycle spreading code included in the long-cycle spreading code group and the code sequence obtained by multiplying the short-cycle spreading code by double A second correlator for each set, and a code candidate for detecting each of a plurality of long-cycle spreading code candidates for spreading the multicarrier signal according to each of the plurality of correlation values calculated by the second correlator From the detection unit, the plurality of reception timing candidates detected by the timing detection unit, and the plurality of long-cycle spreading code candidates detected by the code candidate detection unit, the reception timing of the long-cycle spreading code and the long-cycle spreading code A timing for detecting a code and a code detection unit, the reception timing of the long-cycle spreading code detected by the timing and code detection unit and the long-cycle spreading code, the multi-carrier received by the signal receiving unit A receiving device in a multi-carrier CDMA mobile communication system comprising a demodulation circuit for demodulating the data sequence from a signal. . 15. A multi-carrier CDMA for transmitting a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by using a plurality of subcarriers. A receiving device in a mobile communication system of a system, comprising: a receiving and receiving unit that receives a multicarrier signal including a synchronization signal in which only one or more subcarriers are multiplied by a synchronization signal spreading code; From the multi-carrier signal received by the FFT timing detection unit that detects FFT timing based on the correlation characteristic of the guard interval included therein; and FFT at the FFT timing detected by the FFT timing detection unit, A subcarrier separation unit that separates into carrier components; Of the subcarrier component of, a correlator that obtains the correlation value between the subcarrier component including the synchronization signal and the synchronization signal replica, and the reception timing of the long-cycle spreading code according to the correlation value obtained by the correlator. A receiving device in a mobile communication system of a multi-carrier CDMA system, comprising: a timing detecting section for detecting. 16. A multi-carrier CDMA for transmitting a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by double, using a plurality of subcarriers. A receiving device in a mobile communication system of a system, comprising: a receiving and receiving unit that receives a multicarrier signal including a synchronization signal in which only one or more subcarriers are multiplied by a synchronization signal spreading code; From the multi-carrier signal received by the FFT timing detection unit that detects FFT timing based on the correlation characteristic of the guard interval included therein; and FFT at the FFT timing detected by the FFT timing detection unit, A subcarrier separation unit that separates into carrier components; Of the subcarrier components of the subcarrier component including the synchronization signal and the synchronization signal replica, and the long period according to the correlation value obtained by the first correlator. A timing detection unit that detects a reception timing of a spread code, a subcarrier component separated by the subcarrier separation unit according to a reception timing of the long cycle spread code detected by the timing detection unit, and the long cycle spread code. A second correlator that obtains a correlation value of a code sequence obtained by multiplying each long-cycle spreading code and the short-cycle spreading code included in the group by double, and the correlation obtained by the second correlator A code detection unit that detects a long-cycle spreading code that spreads the multi-carrier signal according to a value, a reception timing of the long-cycle spreading code that the timing detection unit detects, and the code detection unit. And a demodulation circuit that demodulates the data sequence from the multicarrier signal received by the signal receiving unit by using the long-cycle spreading code detected by the unit. . 17. A mobile communication system for transmitting, using a plurality of subcarriers, a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in the long-cycle spreading code group by double multiplication. In the receiving method in 1, a receiving step of receiving a receiving signal including the plurality of subcarriers having a synchronizing signal obtained by multiplying one or a plurality of subcarriers by only a spreading code for a synchronizing signal, and receiving in the receiving step A correlation output step of outputting a correlation value between the received signal and the synchronization signal replica, and an FF according to the correlation value output in the correlation output step.
A reception method in a mobile communication system, comprising: a T timing and a timing detection step of detecting a reception timing of the long-period spreading code. 18. A mobile communication system for transmitting, using a plurality of subcarriers, a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by double multiplication. In the receiving method in 1, a receiving step of receiving a receiving signal including the plurality of subcarriers having a synchronizing signal obtained by multiplying one or a plurality of subcarriers by only a spreading code for a synchronizing signal, and receiving in the receiving step A separation step of separating the received signal into a plurality of subcarrier components, and a correlation between a subcarrier component included in the synchronization signal and a synchronization signal replica among the plurality of subcarrier components separated in the separation step. A correlation output step of outputting a value, and a reception timing of the long-period spreading code according to the correlation value output in the correlation output step How reception in a mobile communication system; and a timing detection step of detecting. 19. The separation step performs FFT according to a plurality of FFT timings, and the timing detection step includes a purpose according to a correlation value output in the correlation output step for all the FFT timings. 19. The reception method in the mobile communication system according to claim 18, wherein the FFT timing to be performed and the reception timing of the long-period spreading code are detected. 20. A separation step of performing FFT according to the FFT timing detected in the timing detection step to separate the received signal into a plurality of subcarrier components, and the long cycle detected in the timing detection step. Correlation detection between the subcarrier component and a code sequence obtained by multiplying each of the long-cycle spreading code and the short-cycle spreading code included in the long-cycle spreading code group according to the reception timing of the spreading code. It further comprises: a correlation detection step of outputting a value; and a code detection step of detecting a long-period spreading code for spreading the received signal according to the correlation detection value output from the correlation detection step. Item 20. A reception method in the mobile communication system according to Item 17 or 19. 21. A mobile communication system for transmitting, using a plurality of subcarriers, a data sequence in which a short-cycle spreading code and one long-cycle spreading code included in a long-cycle spreading code group are doubly multiplied. In the receiving method in, a receiving step of receiving a receiving signal including the plurality of subcarriers having a synchronizing signal obtained by multiplying one or a plurality of subcarriers by only a synchronizing signal spreading code; The received signal is subjected to FFT according to a plurality of FFT timings to be separated into a plurality of subcarrier components, and the plurality of subcarrier components separated in the separating step are included in the synchronization signal. Correlation output step for outputting the correlation value between the subcarrier component to be reproduced and the synchronization signal replica, and the correlation output in the correlation output step According to the timing detection step of detecting the reception timing of the long-cycle spreading code, the subcarrier component and the long-cycle spreading code according to the reception timing of the long-cycle spreading code detected in the timing detection step. A correlation detection step of outputting a correlation detection value of a code sequence obtained by multiplying each long-cycle spreading code included in the code group and the short-cycle spreading code by double, and the correlation detection for all the FFT timings. According to the correlation detection value output from the step, the FFT
A receiving method in a mobile communication system, comprising: a timing; a reception timing of the long-cycle spreading code; and a code detecting step of detecting a long-cycle spreading code for spreading the received signal. 22. A mobile communication system for transmitting, using a plurality of subcarriers, a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by double multiplication. In the receiving method in, the FFT timing detection step of detecting the FFT timing from the received multicarrier signal based on the correlation characteristic of the guard interval included therein, and the FFT timing obtained in the FFT timing detection step, FFT is performed. , A separation step of separating the plurality of subcarrier components, and a correlation for outputting a correlation value between the subcarrier component included in the synchronization signal and the synchronization signal replica among the plurality of subcarrier components separated in the separation step According to the output step and the correlation value output in the correlation output step, How reception in a mobile communication system; and a timing detection step of detecting a reception timing of the long period spreading code. 23. The subcarrier component, each long-cycle spreading code included in the long-cycle spreading code group, and the short-cycle spreading code according to the reception timing of the long-cycle spreading code detected in the timing detection step. A correlation detection step for outputting a correlation detection value with a code sequence obtained by multiplying the code by a double, and a long period spreading code for spreading the received signal according to the correlation detection value output from the correlation detection step. The receiving method in the mobile communication system according to claim 22, further comprising a code detecting step of detecting. 24. A multi-carrier CDMA for transmitting, by using a plurality of subcarriers, a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by double multiplication. A receiving device in a mobile communication system of a system, comprising: a receiving and receiving unit that receives a multicarrier signal including a synchronization signal in which only one or more subcarriers are multiplied by a synchronization signal spreading code; From the received multi-carrier signal, the FFT timing detection unit for detecting a plurality of FFT timing candidates based on the correlation characteristics of the guard interval included in the multi-carrier signal, the FFT timing detection unit, the multi-carrier signal and the multi-carrier signal concerned. 1 carrier signal
A multiplication unit that multiplies the signal delayed by the symbol length, an integrator that obtains a correlation value by integrating the multiplication value multiplied by the multiplication unit over one guard interval length, and a correlation value obtained by the integrator and its A first memory for storing the timing; a second memory for storing a plurality of FFT timing candidates sequentially provided; a plurality of FFT timing candidates for the first memory and a plurality of FFT timing candidates stored in the second memory; A search range setting unit that sets a search range for each of the plurality of FFT timing candidates based on a stored value; first, a maximum correlation value and timing are selected from the stored values of the first memory, and the FFT timing candidate # 1 is stored in the second memory, and then the search range setting unit stores the FFT timing candidate stored in the second memory and the FFT timing candidate stored in the second memory. The search range is set based on the storage value of the first memory, the maximum correlation value and the timing are selected from the storage value of the first memory within the search range, and the maximum correlation value and timing are selected as the FFT timing candidate # 2 in the second memory. A receiving device in a mobile communication system of a multi-carrier CDMA system, comprising a timing detection circuit which stores the same and repeats detection until a predetermined number of FFT timing candidates set in advance are detected by the same procedure. 25. The multi-carrier C according to claim 24.
In a receiver in a DMA mobile communication system, a plurality of subcarriers that perform FFT on the multicarrier signal in each of the predetermined number of FFT timing candidates detected by the FFT timing detection unit and separate into a plurality of subcarrier components are provided. A carrier demultiplexing unit and a plurality of first correlators for obtaining a correlation value between a subcarrier component including the synchronization signal and a synchronization signal replica among the plurality of subcarrier components separated by each of the plurality of subcarrier demultiplexing units. A plurality of timing detection units that detect long-cycle spreading code reception timing candidates according to the correlation values obtained by the plurality of first correlators, and the plurality of timing detection units that detect the plurality of timing detection units. Of the plurality of sub-carriers depending on the respective reception timing candidates of the long-cycle spreading code of A plurality of second correlators for obtaining a correlation value between a rear component, a code sequence obtained by multiplying each of the long-cycle spreading codes included in the long-cycle spreading code group, and the short-cycle spreading code, A plurality of code candidate detection units that detect a plurality of long-cycle spreading code candidates that spread the multi-carrier signal according to the plurality of correlation values obtained by the plurality of second correlators, respectively; From the plurality of reception timing candidates detected by the timing detection unit and the plurality of long period spreading code candidates detected by the plurality of code candidate detecting units, the reception timing of the long period spreading code and the long period spreading code Using the timing and code detection unit for detecting the signal, the reception timing of the long-cycle spreading code detected by the timing and code detection unit, and the long-cycle spreading code. Part receiving apparatus in a mobile communication system of a multicarrier CDMA system comprising includes a is a demodulation circuit for demodulating the data sequence from said multicarrier signal received. 26. The multi-carrier C according to claim 24.
In a receiving device in a DMA mobile communication system, a plurality of FFT timing candidates detected by the FFT timing detection unit are subjected to FFT with respect to the multi-carrier signal and separated into a plurality of sub-carrier components. 1 FFT circuit, and a plurality of first sub-carrier components separated by the plurality of first FFT circuits, a plurality of first sub-carrier components including the sync signal and a plurality of first sub-carrier components for obtaining a correlation value between the sub-carrier components and the sync signal replica. A correlator, a timing detection unit that detects a reception timing and an FFT timing of the long-cycle spreading code according to a correlation value obtained by each of the plurality of first correlators, and the timing detection unit detects the timing detection unit. FFT is performed according to the FFT timing, and the multicarrier signal is converted into a plurality of subcarriers. A second FFT circuit that is separated into components, a plurality of subcarrier components that are separated by the second FFT circuit according to the reception timing of the long-cycle spreading code detected by the timing detection unit, and the long-cycle spread A second correlator that obtains a correlation value between a code sequence obtained by multiplying each long-cycle spreading code included in the code group and the short-cycle spreading code by double, and the second correlator that is obtained by the second correlator A code detection unit that detects a long-cycle spreading code that spreads the multi-carrier signal according to a correlation value, a reception timing of the long-cycle spreading code detected by the timing detection unit, and the length detected by the code detection unit. And a demodulation circuit that demodulates the data sequence from the multicarrier signal received by the signal receiving unit using a period spreading code. Receiving device in the arm. 27. A signal receiving method in a mobile communication system for transmitting a code sequence by using a plurality of subcarriers, wherein the mobile communication system has a step of detecting a plurality of FFT timing candidates from a correlation characteristic of a guard interval. How to receive signals. 28. The method of receiving a signal in a mobile communication system according to claim 27, wherein the step of multiplying the received signal by a signal obtained by delaying the received signal by one symbol length, and the obtained multiplication values are averaged. Equal to the step of moving average using the interval as the guard interval length, the step of adding in-phase the correlation series of multiple correlation values obtained by moving average for each guard interval insertion period, and the guard interval insertion period obtained by in-phase addition A step of detecting a plurality of FFT timing candidates from a correlation sequence of length, the method of receiving a signal in a mobile communication system. 29. The method of receiving a signal in a mobile communication system according to claim 28, wherein a timing having a maximum correlation value in a correlation series having a length equal to a guard interval insertion period obtained by in-phase addition is set. The step of making the first FFT timing candidate and the second and subsequent FFT timing candidates each have the maximum correlation value among the remaining correlation sequences obtained by excluding the peripheral W samples of each of the already detected FFT timing candidates as an exclusion window. A method of receiving a signal in a mobile communication system, the method including: detecting a predetermined number of FFT timing candidates by repeating a method of setting the timing having the above as a next FFT timing candidate. 30. The method of receiving a signal in the mobile communication system according to claim 29, wherein the exclusion window has a preset W / value centered on an FFT timing candidate already detected when setting the window. A method of receiving a signal in a mobile communication system, characterized in that the width is set to 2 samples each before and after. 31. The signal receiving method in the mobile communication system according to claim 29, wherein the number of samples W of the exclusion window and the position thereof are already detected when the exclusion window is set.
A method for receiving a signal in a mobile communication system, characterized in that setting is performed based on the magnitude of the slope of a correlation sequence having the position of the FT timing candidate as the apex. 32. The signal receiving method in the mobile communication system according to claim 29, wherein the number of samples W of the exclusion window and the position thereof are already detected when the exclusion window is set.
A method for receiving a signal in a mobile communication system, characterized in that setting is performed based on the magnitude of a correlation value in an FT timing candidate. 33. The signal receiving method in the mobile communication system according to claim 29, wherein a plurality of FFTs are provided before and after the detected FFT timing candidates.
A method of receiving a signal in a mobile communication system, comprising the step of providing timing candidates. 34. The signal receiving method in a mobile communication system according to claim 28, wherein FFT is performed on a plurality of FFT timing candidates to separate into a plurality of subcarrier components, and a plurality of separated subcarriers are included. Among the carrier components, a step of outputting a correlation value between a subcarrier component including a synchronization signal and a synchronization signal replica, and detecting one or a plurality of long-cycle spreading code reception timing candidates according to the output correlation value. And a subcarrier component and each long-cycle spreading code and each short-cycle spreading code included in the long-cycle spreading code group according to the detected reception timing candidate of one or more long-cycle spreading codes. The step of outputting the correlation detection value with the code product that has been double-multiplied, and the output for all the detected FFT timing candidates. According to the correlation detection value, the reception method for a mobile communication system definitive signal, characterized by a step of detecting a long period spreading code for spreading the received signal and the reception timing of the FFT timing and the long period spreading code. 35. A mobile communication system for transmitting, using a plurality of subcarriers, a data sequence obtained by multiplying a short-cycle spreading code and any one long-cycle spreading code included in a long-cycle spreading code group by double multiplication. In the method of receiving a signal according to the above method, a signal obtained by separating a received signal into subcarrier components by processing such as FFT, each long-cycle spreading code included in the long-cycle spreading code group, and the short-cycle spreading code are double When outputting the correlation detection value with the product code sequence, the correlation value of each symbol for each subcarrier is Navg in the time direction.
Symbol (Navg is an integer greater than or equal to 1) In-phase addition is performed, and the in-phase addition value for each subcarrier is Nc adjacent in the frequency direction.
s subcarriers (Ncs is an integer 1 ≦ Ncs ≦ N, where N is the number of subcarriers), in-phase addition is performed, and Nps in-phase addition values for each Ncs sub-carrier in the frequency direction (Nps is 1 ≦ Nps ≦ A method of receiving a signal in a mobile communication system, wherein an average correlation value is detected by adding powers (N / Ncs). 36. When Nps <(N / Ncs), (N / Ncs) /
The method of receiving a signal in a mobile communication system according to claim 35, wherein Nps long-period spreading codes are alternately detected in correlation in the frequency direction for each Ncs subcarrier.