The application be submitted on November 10th, 2005, application number be 200510120450.5, denomination of invention divides an application for the application of " sending method, method of reseptance, dispensing device, receiving system ".
Background technology
Now, as the digital broadcasting mode in the surface wave TV broadcasting, studied use OFDM (hereinafter referred to as OFDM) technology.This OFDM transmission means is a kind of of multi-carrier modulation, modulates transmitting digital information in a plurality of carrier waves with the mutually orthogonal frequency relation of each code element.This mode is transmitted by above-mentioned like that digital information being divided in a plurality of carrier waves, therefore, be used to modulate the code element of divided digital information of a carrier wave during length elongated, have the character of the influence of the delay ripple that is difficult to be subjected to multipath etc.
As the existing digital broadcasting mode of using the TV signal of OFDM transmission technology, can exemplify out: the DVB-T standard in Europe, i.e. ETSI 300 744 (ETSI:EuropeanTelecommunications Standards Institute).
Existing OFDM transmission means is used the carrier wave of 1705 carrier waves in full transmission band by for example 2k pattern (number of samples of the high speed Fourier transform when the 2k representative generates ofdm signal is 2048), wherein, the carrier wave of 142 carrier waves is used for scattered pilot (Scattered Pilot) signal, the carrier wave of 45 carrier waves is used for continuous pilot (Continual Pilot) signal, the carrier wave of 17 carrier waves is used for control information (TPS), the carrier wave of 1512 carrier waves is used for transmission information signal.
But, in the continuous pilot signal of the carrier wave of 45 carrier waves, the continuous pilot signal of the carrier wave of 11 carrier waves and scattered pilot repeated configuration.And the frequency configuration in the code element of scattered pilot signal is configured to 12 carrier cycles, and for each code element, this frequency configuration moves and disposes every 3 carrier waves, and the time is configured as 4 code-element periods.
Specifically, make carrier index k from an end in order from 0 to 1704, making the symbol number n in the frame is from 0 to 67, and at this moment, the scattered pilot signal is configured in the carrier wave of the carrier index k in (1) formula.In (1) formula, mod represents the complementation computing, and p is the integer below 141 more than 0.
k=3(n mod 4)+12p (1)
Continuous pilot signal is configured in carrier index k={0,48,54,87,141,156,192,201,255,279,282,333,432,450,483,525,531,618,636,714,759,765,780,804,873,888,918,939,942,969,984,1050,1101,1107,1110,1137,1140,1146,1206,1269,1323,1377,1491,1683, in the carrier wave of 1704}.
These disperse and continuous pilot signal is basis and the serial w of the corresponding PN of carrier index k (pseudo random number) that disposes respectively
kCome with the complex vector c shown in (2) formula
K, nModulated carrier is resulting.In (2) formula, Re{c
K, nRepresentative and the corresponding complex vector c of carrier wave of carrier index k, symbol number n
K, nReal part, Im{c
K, nRepresent imaginary part.
And the control information signal that is called as TPS (Transmission Parameter Signaling sends parameter signal) is configured in carrier index k={34,50,209,346,413,569,595,688,790,901,1073,1219,1262,1286,1469,1594, in the carrier wave of 1687}, each code element is transmitted the control information of 1 bit.
When making with the symbol number is the code element control information transmission bit of n when being Sn, and the control information signal is that the n modulated carrier is resulting with the complex vector ck shown in (3) formula.That is, the carrier wave of control information transmission signal carries out differential 2 value PSK (Phase Shift Keying, frequency shift keying) modulation between code element.
But in the stem code element (symbol number n=0) of frame, the carrier wave of control information transmission is according to the above-mentioned complex vector ck of PN series Wk shown in (4) formula, and n modulates.
The carrier wave that is used for 1512 carrier waves of above-mentioned carrier wave transmission information signal in addition carries out QPSK, 16QAM or 64QAM modulation according to digital information.Any modulation system all is the absolute phase modulation.
In Figure 10, represented to receive an example of the existing receiving system of such ofdm signal that generates and demodulation digital information.
In Figure 10, the ofdm signal that is received carries out frequency translation by tuner 101, carries out the T/F conversion by Fourier transform circuit 102, and becomes the vector string of each carrier wave in carrier wave zone.This vector string is provided for scattered pilot and extracts circuit 103 and continuous pilot extraction circuit 109.
Scattered pilot extracts the vector string extraction scattered pilot signal of circuit 103 from Fourier transform circuit 102 outputs.Vector generation circuit 104 takes place and extracts the corresponding modulated complex vector C of scattered pilot signal that circuit 103 is extracted by scattered pilot
K, nDivision circuit 105 will extract scattered pilot signal that circuit 103 extracted divided by the complex vector that is produced by vector generation circuit 104 by scattered pilot, infer transmission path characteristic with scattered pilot signal correction from this division arithmetic result.
Interpolating circuit 106 interpolations with by the transmission path characteristic of division circuit 105 resulting scattered pilot signal corrections, and infer and whole relevant transmission path characteristic of carrier wave.Division circuit 107 with the vector string of Fourier transform circuit 102 output divided by the transmission path characteristic of being inferred, to carry out synchronous detection by the interpolating circuit 106 relevant with corresponding respectively carrier wave.The modulation system (QPSK, 16QAM, 64QAM etc.) of demodulator circuit 108 when generating transmission information signal comes the synchronous detection signal of division circuit 107 outputs is carried out demodulation, and obtains the digital information transmitted.
Continuous pilot is extracted the vector string extraction continuous pilot signal of circuit 109 from Fourier transform circuit 102 outputs.Vector generation circuit 110 takes place and extracts the corresponding modulated complex vector C of continuous pilot signal that circuit 109 is extracted by continuous pilot
K, nDivision circuit 111 will extract circuit 109 continuous pilot signal that is extracted and the complex vector that takes place with vector generation circuit 110 by continuous pilot and be divided by, and infer the transmission path characteristic relevant with continuous pilot signal.112 pairs of transmission path characteristic relevant with the continuous pilot signal of being inferred by division circuit 111 of inverse fourier transform circuit are carried out frequency-time change, and obtain the pusle response characteristics of transmission path.
But, the prerequisite of existing OFDM transmission means is to use the transmission path characteristic that obtains like this: the modulation of the carrier wave of transmitting digital information is carried out the absolute phase modulation undertaken by QPSK, 16QAM, 64QAM etc., to this demodulation, the transmission path characteristic that level and smooth interpolation is inferred from last sparse scattered pilot signal of time, therefore, exist because of decline and wait the situation that can not obtain enough transmission qualities in the variation of transmission path characteristic rapidly in the mobile communication.
And, in existing OFDM transmission means, the modulation system of each carrier wave is defined as one in all frequency bands, therefore, in order to be suitable for moving for example differential QPSK modulation that receives and in the modulation of the carrier wave of transmitting digital information, import, even like this while moving the digital information that receive a part, all transmission capacities tail off, then deterioration of efficiency.
And, because continuous pilot signal is configured in in the carrier wave of predetermined carrier spacing A any, the turning back of A/one of length (inverse of the minimum frequency space of carrier wave) during the effective code element then taken place the pusle response characteristics of the transmission path that can infer from continuous pilot signal.
Therefore, in order to solve above-mentioned problem, the purpose of this invention is to provide a kind of OFDM mode and the dispensing device, the receiving system that are suitable for this mode, this OFDM mode can not only be kept all transmission capacities but also partly import in the modulation of the carrier wave of transmitting digital information and be suitable for moving the modulation system that receives, and, configuration continuous pilot signal and can in the impulse response of the transmission path of inferring, not turning back by continuous pilot signal.
Summary of the invention
Therefore, in order to solve above-mentioned problem, the purpose of this invention is to provide a kind of OFDM mode and the dispensing device, the receiving system that are suitable for this mode, this OFDM mode can not only be kept all transmission capacities but also partly import in the modulation of the carrier wave of transmitting digital information and be suitable for moving the modulation system that receives, and, configuration continuous pilot signal and can in the impulse response of the transmission path of inferring, not turning back by continuous pilot signal.
In order to address the above problem, the invention provides a kind of sending method that digital information is sent as ofdm signal, it is characterized in that, described ofdm signal, comprise the section that constitutes by the continuous a plurality of carrier waves of frequency more than 2 or 2, described section, be synchronous detection any one with section or differential detection usefulness section, described synchronous detection section, comprise the carrier wave that has distributed the additional information transmission signals, with the carrier wave that has distributed transmission information signal, use in the section at described synchronous detection, described additional information transmission signals is assigned to particular carrier wave, use in the section at described synchronous detection, described transmission information signal is assigned to any carrier wave beyond the carrier wave that has distributed described additional information transmission signals, described differential detection section, comprise the carrier wave that has distributed the additional information transmission signals, with the carrier wave that has distributed transmission information signal, use in the section in described differential detection, described additional information transmission signals is assigned to particular carrier wave, use in the section in described differential detection, described transmission information signal is assigned to any carrier wave beyond the carrier wave that has distributed described additional information transmission signals, described differential detection is with the position of the carrier wave that has distributed described additional information transmission signals in the section, comprise the position of described synchronous detection with the carrier wave that has distributed described additional information transmission signals in the section, the described synchronous detection described transmission information signal of section, according to described digital information the carrier wave that is assigned to is respectively carried out the absolute phase modulation, described differential detection is carried out differential modulation according to described digital information to the carrier wave that is assigned to respectively with the described transmission information signal of section.
Preferably, in above-mentioned sending method, the modulation of described absolute phase is any one of QPSK modulation, 16QAM modulation, 64QAM modulation.
Preferably, in above-mentioned sending method, the described differential DQPSK modulation that is modulated to.
Preferably, in above-mentioned sending method, described additional information transmission signals carries out differential modulation according to additional information to the carrier wave that is assigned to respectively.
Preferably, in above-mentioned sending method, be modulated to the DBPSK modulation with respect to described additional information transmission signals described differential.
The present invention also provides a kind of method of reseptance that receives ofdm signal and reduce digital information, it is characterized in that, described ofdm signal, comprise the section that constitutes by the continuous a plurality of carrier waves of frequency more than 2 or 2, described section, be synchronous detection any one with section or differential detection usefulness section, described synchronous detection section, comprise the carrier wave that has distributed the additional information transmission signals, with the carrier wave that has distributed transmission information signal, use in the section at described synchronous detection, described additional information transmission signals is assigned to particular carrier wave, use in the section at described synchronous detection, described transmission information signal is assigned to any carrier wave beyond the carrier wave that has distributed described additional information transmission signals, described differential detection section, comprise the carrier wave that has distributed the additional information transmission signals, with the carrier wave that has distributed transmission information signal, use in the section in described differential detection, described additional information transmission signals is assigned to particular carrier wave, use in the section in described differential detection, described transmission information signal is assigned to any carrier wave beyond the carrier wave that has distributed described additional information transmission signals, described differential detection is with the position of the carrier wave that has distributed described additional information transmission signals in the section, comprise the position of described synchronous detection with the carrier wave that has distributed described additional information transmission signals in the section, the described synchronous detection described transmission information signal of section, according to described digital information the carrier wave that is assigned to is respectively carried out the absolute phase modulation, the described differential detection described transmission information signal of section, according to described digital information the carrier wave that is assigned to is respectively carried out differential modulation, after described ofdm signal carried out Fourier transform, described synchronous detection is carried out synchronous detection with section, described differential detection is carried out differential detection with section, thereby reduce described digital information.
Preferably, in above-mentioned method of reseptance, the modulation of described absolute phase is any one of QPSK modulation, 16QAM modulation, 64QAM modulation.
Preferably, in above-mentioned method of reseptance, the described differential DQPSK modulation that is modulated to.
Preferably, in above-mentioned method of reseptance, described additional information transmission signals carries out differential modulation according to additional information to the carrier wave that is assigned to respectively.
Preferably, in above-mentioned method of reseptance, be modulated to the DBPSK modulation with respect to described additional information transmission signals described differential.
The present invention also provide a kind of with digital information as the dispensing device that ofdm signal sends, it is characterized in that, comprising: the carrier wave inking device, transmission information signal and additional information transmission signals are distributed to predetermined carrier wave; With the inverse Fourier transform device, carry out inverse Fourier transform by output to described carrier wave inking device, generate described ofdm signal, described ofdm signal, comprise the section that constitutes by the continuous a plurality of carrier waves of frequency more than 2 or 2, described section, be synchronous detection any one with section or differential detection usefulness section, described synchronous detection section, comprise the carrier wave that has distributed the additional information transmission signals, with the carrier wave that has distributed transmission information signal, use in the section at described synchronous detection, described additional information transmission signals is assigned to particular carrier wave, use in the section at described synchronous detection, described transmission information signal is assigned to any carrier wave beyond the carrier wave that has distributed described additional information transmission signals, described differential detection section, comprise the carrier wave that has distributed the additional information transmission signals, with the carrier wave that has distributed transmission information signal, use in the section in described differential detection, described additional information transmission signals is assigned to particular carrier wave, use in the section in described differential detection, described transmission information signal is assigned to any carrier wave beyond the carrier wave that has distributed described additional information transmission signals, described differential detection is with the position of the carrier wave that has distributed described additional information transmission signals in the section, comprise the position of described synchronous detection with the carrier wave that has distributed described additional information transmission signals in the section, the described synchronous detection described transmission information signal of section, according to described digital information the carrier wave that is assigned to is respectively carried out the absolute phase modulation, described differential detection is carried out differential modulation according to described digital information to the carrier wave that is assigned to respectively with the described transmission information signal of section.
Preferably, in above-mentioned dispensing device, the modulation of described absolute phase is any one of QPSK modulation, 16QAM modulation, 64QAM modulation.
Preferably, in above-mentioned dispensing device, the described differential DQPSK modulation that is modulated to.
Preferably, in above-mentioned dispensing device, described additional information transmission signals carries out differential modulation according to additional information to the carrier wave that is assigned to respectively.
Preferably, in above-mentioned dispensing device, be modulated to the DBPSK modulation with respect to described additional information transmission signals described differential.
The present invention also provides a kind of receiving system that receives ofdm signal and reduce digital information, it is characterized in that, described ofdm signal, comprise the section that constitutes by the continuous a plurality of carrier waves of frequency more than 2 or 2, described section, be synchronous detection any one with section or differential detection usefulness section, described synchronous detection section, comprise the carrier wave that has distributed the additional information transmission signals, with the carrier wave that has distributed transmission information signal, use in the section at described synchronous detection, described additional information transmission signals is assigned to particular carrier wave, use in the section at described synchronous detection, described transmission information signal is assigned to any carrier wave beyond the carrier wave that has distributed described additional information transmission signals, described differential detection section, comprise the carrier wave that has distributed the additional information transmission signals, with the carrier wave that has distributed transmission information signal, use in the section in described differential detection, described additional information transmission signals is assigned to particular carrier wave, use in the section in described differential detection, described transmission information signal is assigned to any carrier wave beyond the carrier wave that has distributed described additional information transmission signals, described differential detection is with the position of the carrier wave that has distributed described additional information transmission signals in the section, comprise the position of described synchronous detection with the carrier wave that has distributed described additional information transmission signals in the section, the described synchronous detection described transmission information signal of section, according to described digital information the carrier wave that is assigned to is respectively carried out the absolute phase modulation, the described differential detection described transmission information signal of section, according to described digital information the carrier wave that is assigned to is respectively carried out differential modulation, this receiving system comprises: Fourier transform device, described ofdm signal is carried out Fourier transform, and detector arrangement, in the output of described Fourier transform device, described synchronous detection is carried out synchronous detection with section, described differential detection is carried out differential detection with section.
Preferably, in above-mentioned receiving system, the modulation of described absolute phase is any one of QPSK modulation, 16QAM modulation, 64QAM modulation.
Preferably, in above-mentioned receiving system, the described differential DQPSK modulation that is modulated to.
Preferably, in above-mentioned receiving system, described additional information transmission signals carries out differential modulation according to additional information to the carrier wave that is assigned to respectively.
Preferably, in above-mentioned receiving system, be modulated to the DBPSK modulation with respect to described additional information transmission signals described differential.
Embodiment
Below to OFDM transmission means involved in the present invention and be suitable for the dispensing device of this OFDM transmission means, the embodiment of receiving system is elaborated.
First embodiment
In the OFDM of present embodiment transmission means, by 13 sections with use the band terminal pilot tone of the carrier wave of a carrier wave to form, section is made of the carrier wave of 108 carrier waves.Each section is made of with one of section with section or differential detection synchronous detection.In all frequency bands, use the carrier wave of 1405 carrier waves.
In Fig. 1, express synchronous detection usefulness or differential detection configuration example with section (adding up to 13 sections), band terminal pilot signal.Transverse axis is represented frequency axis (carrier wave configuration), longitudinal axis express time axle (code element direction).As 0 to 107 integer, section is made of the carrier wave of 108 carrier waves the carrier index k ' in each section.
Synchronous detection uses the transmission information signal of the carrier wave of the scattered pilot signal of the carrier wave of 9 carrier waves, the additional information transmission signals that uses the carrier wave of 3 carrier waves, 96 carrier waves of use to be constituted with section by each code element.
Differential detection is constituted with the transmission information signal of section by the carrier wave of the additional information transmission signals of the carrier wave that uses 11 carrier waves, the terminal pilot signal of using the carrier wave of 1 carrier wave, 96 carrier waves of use.
Like this, owing to use section and differential detection with the carrier wave that uses 108 same number in the section, then can not change needed transmission band by the combination of section at synchronous detection.
Wherein, making carrier index k in all frequency bands is 0 to 1404 integer, and making sector number i is 0 to 12 integer, and making carrier index k ' in each section is 0 to 107 integer, then satisfies k=i108+k '.
Being arranged on synchronous detection is configured in each section and the carrier wave by the carrier index k ' in (5) section that formula produced with the scattered pilot signal in the section.In (5) formula, mod represents the complementation computing, and the n of expression symbol number is the integer more than 0, and p is the integer below 8 more than 0.
k′=3(n mod 4)+12p (5)
Being located at synchronous detection is configured in respectively in the carrier wave of the carrier index k ' in each section shown in the table 1 with the additional information transmission signals in the section with section and differential detection.Table 1 expression synchronous detection is included in differential detection with in the additional information transmission signals of section with the additional information transmission signals of section.
By above formation, even mix under the state that exists with section with section and differential detection at synchronous detection, must configuration additional information transmission signals in the carrier wave that is defined with the additional information transmission signals of section as synchronous detection, then carry out the identification of additional information transmission signals or transmission signals in addition easily at receiver side.And the additional information of passing through to be transmitted is come distributing carrier wave so that can not become the part set configuration.
The frequency configuration of table 1 additional information transmission signals
Sector number i |
Carrier index k ' |
Synchronous detection is used |
Differential detection is used |
No.0 |
10 50 |
28 |
3 13 |
10 50 |
28 70 |
45 83 |
59 87 |
77 |
No.1 |
53 25 |
83 |
3 25 |
15 63 |
40 73 |
53 80 |
58 93 |
83 |
No.2 |
61 71 |
100 |
29 4 |
41 7 |
61 17 |
84 51 |
93 71 |
100 |
No.3 |
11 55 |
101 |
11 36 |
28 48 |
45 55 |
81 59 |
91 86 |
101 |
No.4 |
20 44 |
40 |
20 10 |
23 28 |
40 44 |
63 47 |
85 54 |
105 |
No.5 |
74 25 |
100 |
30 7 |
74 25 |
81 47 |
92 60 |
100 87 |
103 |
No.6 |
35 49 |
79 |
3 49 |
35 61 |
72 96 |
79 99 |
85 104 |
89 |
No.7 |
76 65 |
97 |
5 31 |
18 39 |
57 47 |
76 65 |
92 72 |
97 |
No.8 |
4 74 |
89 |
4 16 |
13 30 |
89 37 |
93 74 |
98 83 |
102 |
No.9 |
40 5 |
89 |
40 5 |
72 10 |
89 21 |
95 44 |
100 61 |
105 |
No.10 |
8 85 |
64 |
8 78 |
36 82 |
48 85 |
52 98 |
64 102 |
74 |
No. 11 |
7 70 |
89 |
7 34 |
25 48 |
30 54 |
42 70 |
89 101 |
104 |
No. 12 |
98 37 |
101 |
10 23 |
30 37 |
55 51 |
81 68 |
98 105 |
101 |
Being located at differential detection, to be configured in carrier index k ' in each section with the terminal pilot signal in the section be in 0 the carrier wave.The configuration of terminal pilot signal is the periodic position of the adjacent synchronous detection of maintenance with the frequency configuration of the scattered pilot signal of section.Each terminal pilot signal is replenished this scattered pilot signal.
In Fig. 2, represented the synchronous detection configuration of the scattered pilot signal in the section, the differential detection configuration example of the terminal pilot signal in the section.Transverse axis is represented frequency axis (carrier wave configuration), longitudinal axis express time axle (code element direction).As 0 to 107 integer, section is made of the carrier wave of 108 carrier waves the carrier index k ' in each section.The additional information transmission signals is assigned to the carrier wave different with the scattered pilot signal.
These scattered pilot signals and terminal pilot signal be basis and the carrier index k that is disposed (by the decision of the carrier index k ' in sector number i and each section) the serial w of corresponding PN (pseudo random number) respectively
k(w
k=0,1) passes through the complex vector c shown in (6) formula
K, nCome modulated carrier and obtain.In (6) formula, Re{c
K, nRepresentative and the corresponding complex vector c of carrier wave of carrier index k, symbol number n
K, nReal part, Im{c
K, nRepresent imaginary part.
Being located at synchronous detection is used to transmit and the different additional information of carrier wave institute information transmitted transmission signals of using 96 carrier waves with the additional information transmission signals in the section with differential detection with section.For example, consider the control information of regulation transmission means (each sector number, carrier modulation mode etc.) and the information of utilizing as TV station (control information of for example in relay station, using, TV station's identification with signal etc.).Can in each code element, transmit the additional information of 1 bit, also can transmit the additional information of a plurality of bits.Can only transmit the control information of regulation transmission means.
Wherein, when making the control information bit that is transmitted by the code element of symbol number n be Sn, the control information signal is by the complex vector c shown in (7) formula
K, nCome modulated carrier and obtain.That is, in the case, the carrier wave of control information transmission signal carries out differential 2 value PSK (PhaseShift Keying) modulation between code element.
But in the beginning code element (symbol number n=0) of frame, the carrier wave of control information transmission is according to above-mentioned PN series w
k, by the complex vector c shown in (8) formula
K, nModulate.
And, in each code element, under the situation of the control information of transmission 2 bits, can for example use the differential 4 phase PSK modulation between code element, perhaps a plurality of carrier waves of control information transmission are divided into 2 groups, be distributed into and in each code element, transmit 1 bit respectively.
Be located at synchronous detection and be assigned to above-mentioned synchronous detection with the scattered pilot signal of section, the carrier wave beyond the additional information transmission signals, carry out the absolute phase modulation according to digital information with the transmission information signal in the section.In this absolute phase modulation, use for example QPSK, 16QAM, 64QAM modulation etc.
Synchronous detection carries out demodulation with the transmission information signal of section by following processing.At first, complex vector with modulation this scattered pilot signal, terminal pilot signal and band terminal pilot signal is carried out demodulation to scattered pilot signal and necessary terminal pilot signal, band terminal pilot signal, obtains the transmission path characteristic in the frequency domain relevant with scattered pilot signal and terminal pilot signal etc.And, come that with filter frequency direction and code element direction are carried out interpolation and infer the transmission path characteristic relevant with transmission information signal.Be divided by with transmission path characteristic that obtains like this and transmission information signal.Thus can be from synchronous detection section demodulating information transmission signals.
Be located at differential detection and be assigned to above-mentioned differential detection with the terminal pilot signal of section and the carrier wave outside the additional information transmission signals, come between the adjacent code element of same carrier wave numbering, to carry out differential modulation according to digital information with the transmission information signal in the section.
In this differential modulation, use for example DBPSK, DQPSK, DAPSK etc.Can be divided by with the transmission information signal of section with the transmission information signal of the same carrier wave of above-mentioned code element numbering and differential detection and carry out demodulation.
As described above, the OFDM transmission means of present embodiment, in its receiving system, can carry out high-quality reception by the effect of filter in section at synchronous detection, separate the variation of transferring be suitable for transmission path characteristic by differential between code element in differential detection in section and move the reception that receives rapidly.And, in each section, with section and differential detection section, just can realize the flexible services state that does not change with transmission band by the combination in any synchronous detection.
Second embodiment
In the OFDM of present embodiment transmission means, by 13 sections with use the band terminal pilot tone of the carrier wave of a carrier wave to form, section is made of the carrier wave of 108 carrier waves.Each section is made of with one of section with section or differential detection synchronous detection.In all frequency bands, use the carrier wave of 1405 carrier waves.
Synchronous detection uses the transmission information signal of the carrier wave of the scattered pilot signal of the carrier wave of 9 carrier waves, the continuous pilot signal that uses the carrier wave of 2 carrier waves, the additional information transmission signals (in this embodiment, being called the control information signal) that uses the carrier wave of 1 carrier wave, 96 carrier waves of use to be constituted with section by each code element.
Differential detection is constituted with the transmission information signal of section by the carrier wave of the continuous pilot signal of the carrier wave that uses 6 carrier waves, the control information signal that uses the carrier wave of 5 carrier waves, the terminal pilot signal of using the carrier wave of 1 carrier wave, 96 carrier waves of use.
Wherein, making carrier index k in all frequency bands is 0 to 1404 integer, and making sector number i is 0 to 12 integer, and making carrier index k ' in each section is 0 to 107 integer, then satisfies k=i108+k '.
Being arranged on synchronous detection is configured in each section and the carrier wave by the carrier index k ' in (5) section that formula produced with the scattered pilot signal in the section.In (5) formula, mod represents the complementation computing, and the n of expression symbol number is the integer more than 0, and p is the integer below 8 more than 0.
k′=3(n mod 4)+12p (5)
Being located at synchronous detection is configured in respectively in the carrier wave of the carrier index k ' in each section shown in the table 2 with the continuous pilot signal in the section with section and differential detection.Table 2 expression synchronous detection is included in differential detection with in the continuous pilot signal of section with the continuous pilot signal of section.
The frequency configuration of table 2 continuous pilot signal
Sector number i | Carrier index k ' |
Synchronous detection is used | Differential detection is used |
No.0 | 10 | 28 | 3 | 10 | 28 | 45 | 59 | 77 |
No.1 | 53 | 83 | 3 | 15 | 40 | 53 | 58 | 83 |
No.2 | 61 | 100 | 29 | 41 | 61 | 84 | 93 | 100 |
No.3 | 11 | 101 | 11 | 28 | 45 | 81 | 91 | 101 |
No.4 | 20 | 40 | 20 | 23 | 40 | 63 | 85 | 105 |
No.5 | 74 | 100 | 30 | 74 | 81 | 92 | 100 | 103 |
No.6 | 35 | 79 | 3 | 35 | 72 | 79 | 85 | 89 |
No.7 | 76 | 97 | 5 | 18 | 57 | 76 | 92 | 97 |
No.8 | 4 | 89 | 4 | 13 | 89 | 93 | 98 | 102 |
No.9 | 40 | 89 | 40 | 72 | 89 | 95 | 100 | 105 |
No.10 | 8 | 64 | 8 | 36 | 48 | 52 | 64 | 74 |
No.11 | 7 | 89 | 7 | 25 | 30 | 42 | 89 | 104 |
No.12 | 98 | 101 | 10 | 30 | 55 | 81 | 98 | 101 |
By above formation, even mix under the state that exists with section with section and differential detection at synchronous detection, in the carrier wave of the continuous pilot that is defined as synchronous detection usefulness section, must dispose continuous pilot signal, then carry out the identification of continuous pilot signal or transmission signals in addition easily at receiver side.And, can distributing carrier wave so that can not become the part set configuration.
In the carrier wave of the frequency identical,,, then can utilize as the carrier wave that becomes benchmark at receiver side because frequency, phase place, amplitude are designated with the continuous pilot signal of particular phases and this carrier wave of Modulation and Amplitude Modulation with each code element.
Being located at differential detection, to be configured in carrier index k ' in each section with the terminal pilot signal in the section be in 0 the carrier wave.The configuration of terminal pilot signal is to keep the periodic position of adjacent synchronous detection with the frequency configuration of section scattered pilot signal.Each terminal pilot signal is replenished this scattered pilot signal.
The configuration of continuous pilot signal and control information signal, the configuration that synchronous detection is used the scattered pilot signal in the section, the configuration example that differential detection is used the terminal pilot signal in the section in Fig. 3, have been represented.Transverse axis is represented frequency axis (carrier wave configuration), longitudinal axis express time axle (code element direction).As 0 to 107 integer, section is made of the carrier wave of 108 carrier waves the carrier index k ' in each section.Continuous pilot signal, control information signal are assigned to the carrier wave different with the scattered pilot signal.
These scattered pilot signals, continuous pilot signal and terminal pilot signal be basis and the carrier index k that is disposed (by the decision of the carrier index k ' in sector number i and each section) the serial w of corresponding PN (pseudo random number) respectively
k(w
k=0,1) passes through the complex vector c shown in (6) formula
K, nCome modulated carrier and obtain.In (6) formula, Re{c
K, nRepresentative and the corresponding complex vector c of carrier wave of carrier index k, symbol number n
K, nReal part, Im{c
K, nRepresent imaginary part.
Be located at synchronous detection and be configured in respectively with the control information signal in the section in the carrier wave of the carrier index k ' in each section shown in the table 3, the control information of transmission 1 bit in each code element with section and differential detection.
The frequency configuration of table 3 control information signal
Sector number i |
Carrier index k ' |
Synchronous detection is used |
Differential detection is used |
No.0 |
50 |
13 |
50 |
70 |
83 |
87 |
No.1 |
25 |
25 |
63 |
73 |
80 |
93 |
No.2 |
71 |
4 |
7 |
17 |
51 |
71 |
No.3 |
55 |
36 |
48 |
55 |
59 |
86 |
No.4 |
44 |
10 |
28 |
44 |
47 |
54 |
No.5 |
25 |
7 |
25 |
47 |
60 |
87 |
No.6 |
49 |
49 |
61 |
96 |
99 |
104 |
No.7 |
65 |
31 |
39 |
47 |
65 |
72 |
No.8 |
74 |
16 |
30 |
37 |
74 |
83 |
No.9 |
5 |
5 |
10 |
21 |
44 |
61 |
No.10 |
85 |
78 |
82 |
85 |
98 |
102 |
No.11 |
70 |
34 |
48 |
54 |
70 |
101 |
No.12 |
37 |
23 |
37 |
51 |
68 |
105 |
When making the control information bit that is transmitted by the code element of symbol number n be Sn, the control information signal is by the complex vector c shown in (7) formula
K, nCome modulated carrier and obtain.That is, the carrier wave of control information transmission signal carries out differential 2 value PSK (Phase Shift Keying, phase shift keying) modulation between code element.
But in the beginning code element (symbol number n=0) of frame, the carrier wave of control information transmission is according to above-mentioned PN series w
k, by the complex vector c shown in (8) formula
K, nModulate.
And, in each code element, under the situation of the control information of transmission 2 bits, can use for example differential 4 phase PSK modulation between code element.
Be located at synchronous detection and be assigned to above-mentioned synchronous detection with the carrier wave beyond scattered pilot signal, continuous pilot signal and the control information signal of section, carry out the absolute phase modulation according to digital information with the transmission information signal in the section.In this absolute phase modulation, use for example QPSK, 16QAM, 64QAM modulation etc.
Synchronous detection carries out demodulation with the transmission information signal of section by following processing.At first, complex vector with modulation this scattered pilot signal, terminal pilot signal and band terminal pilot signal is carried out contrary modulation to scattered pilot signal and necessary terminal pilot signal, band terminal pilot signal, infers the transmission path characteristic in the frequency domain relevant with scattered pilot signal and terminal pilot signal etc.And, come that with filter frequency direction and code element direction are carried out interpolation and infer the transmission path characteristic relevant with transmission information signal.Be divided by with transmission path characteristic that obtains like this and transmission information signal.Thus can be from synchronous detection section demodulating information transmission signals.
Be located at differential detection and be assigned to above-mentioned differential detection with the carrier wave outside continuous pilot signal, terminal pilot signal and the control information signal of section, come between the adjacent code element of same carrier wave numbering, to carry out differential modulation according to digital information with the transmission information signal in the section.
In this differential modulation, use for example DBPSK, DQPSK, DAPSK etc.Can carry out demodulation divided by differential detection with the transmission information signal of section with the transmission information signal of the same carrier wave of above-mentioned code element numbering.
As described above, the OFDM transmission means of present embodiment, in its receiving system, can carry out high-quality reception by the effect of filter in section at synchronous detection, separate the variation of transferring be suitable for transmission path characteristic by differential between code element in differential detection in section and move rapidly and receive.And, in each section, with section and differential detection section, just can realize the flexible services state that does not change with transmission band by the combination in any synchronous detection.
Just can determine frequency, phase place and amplitude by configuration in the carrier wave of the frequency identical with the continuous pilot signal of specific phase place and this carrier wave of Modulation and Amplitude Modulation used as reference carrier with each code element.
Fig. 4 and Fig. 5 represent that respectively the synchronous detection shown in the table 2 is right with the inverse fourier transform of the frequency configuration of the continuous pilot signal of section (13 sections, 78 carrier waves) with section (13 sections, 26 carrier waves) and differential detection.From Fig. 4, Fig. 5 as can be seen: they are pulse types, and the frequency configuration of the continuous pilot signal shown in the table 2 is not periodically.
Like this, the OFDM transmission means of present embodiment can prevent the situation that the delay ripple because of multipath etc. all slackens continuous pilot signal.By using this configuration to obtain inverse fourier transform, just can obtain the impulse response of transmission path.And the frequency configuration of continuous pilot signal is the strong configuration of autocorrelation.
Fig. 6 and Fig. 7 represent that respectively the synchronous detection shown in the table 3 is right with the inverse fourier transform of the frequency configuration of the control information signal of section with section and differential detection.From Fig. 6, Fig. 7 as can be seen: they are pulse types, and the frequency configuration of the control information signal shown in the table 3 is not periodically.
Like this, the OFDM transmission means of present embodiment can prevent the situation that the delay ripple because of multipath etc. all slackens the control information signal.
And, can set the frequency configuration of the additional information transmission signals that comprises the control information signal equally.
The 3rd embodiment
Represented that in Fig. 8 OFDM transmission means according to first and second embodiment generates the formation of embodiment of the dispensing device of ofdm signal.
In Fig. 8, come as required the digital information of being imported to be carried out wrong control and treatment (error correction coding and intersection, energy dissipation etc.) and digital modulation with transmission information signal generative circuit 51.And general employed basic wrong control and treatment mode and digital modulation mode are technique known in Digital Transmission, thereby omit its explanation.
Carry out the absolute phase modulation at synchronous detection as digital modulation in section.In this absolute phase modulation, use for example QPSK, 16QAM, 64QAM modulation etc.Carry out differential modulation between according to the adjacent code element of digital information in differential detection in section in same carrier wave numbering.In this differential modulation, use for example DBPSK, DQPSK, DAPSK etc.
Additional information signal generative circuit 52 carries out wrong control and treatment (error correction coding and intersection, energy dissipation etc.) and digital modulation to the additional information of being imported as required.As digital modulation use M (M is the natural number 2 or more) phase PSK (Phase Shift Keying) modulation and differential M on the code element direction mutually PSK modulate etc.
Control information generative circuit 56 is created on the needed transmission means information of receiver side (the various information of transmission meanss such as regulation synchronous detection sector number, differential detection sector number, carrier modulation mode).This information is carried out wrong control and treatment and digital modulation by additional information signal generative circuit 52, also can carry out wrong control and treatment and the digital modulation different with other additional information.
Scattered pilot signal generating circuit 53 generates according to the scattered pilot signal of being modulated with carrier index k (by the decision of the carrier index k ' in sector number i and each section) the serial wk of corresponding PN (pseudo random number) (wk=0,1) by carrier wave configuration circuit 57 specified configuration.
Terminal pilot signal generative circuit 54 generate according to carrier index k (by the decision of the carrier index k ' in sector number i and each section) the serial w of corresponding PN (pseudo random number) by carrier wave configuration circuit 57 specified configuration
k(w
k=0,1) the terminal pilot signal of being modulated.
Band terminal pilot signal generative circuit 55 generates basis and the serial w of the corresponding PN of the carrier index k of band terminal (pseudo random number)
k(w
k=0,1) the band terminal pilot signal of being modulated.
Though continuous pilot signal is not illustrated especially,, it is contemplated that the situation of modulating with the identical phase place of each code element, amplitude by 52 pairs of these carrier waves of additional information signal generative circuit.
In carrier wave configuration circuit 57, each output (complex vector string) of transmission information signal generative circuit 51, additional information signal generative circuit 52, scattered pilot signal generating circuit 53, terminal pilot signal generative circuit 54, band terminal pilot signal generative circuit 55 is configured on the carrier position according to the frequency range of transmission means defined.
For example, the output of scattered pilot signal generating circuit 53 is configured in section with N (N is the natural number 2 or more) carrier spacing and has moved in each code element in the carrier wave of individual (L is the approximate number of the N) carrier wave of L at synchronous detection.The output of terminal pilot signal generative circuit 54 is configured in the carrier wave of carrier index k '=0 in the section in section in differential detection.And the output of additional information signal generative circuit 52 distributes according to example frequency configuration as shown in table 1.The vector string of each carrier wave of Pei Zhi substrate frequency band is transfused to inverse fourier transform circuit 58 like this.
It is time-domain from frequency domain transformation that inverse fourier transform circuit 58 makes the vector string of each carrier wave of the substrate frequency band that is generated by carrier wave configuration circuit 57, additional common employed protection interim and exporting.The output of 59 pairs of inverse fourier transform circuit 58 of quadrature modulation circuit is carried out quadrature modulation and is transformed to intermediate frequency band.Frequency-conversion circuit 60 is the frequency band that has carried out the ofdm signal of quadrature modulation a radio bands from middle frequency band transformation, offers antenna etc.
According to the formed dispensing device of above formation, just can be according to generating ofdm signal in the OFDM transmission means described in first and second embodiment.
The 4th embodiment
Fig. 9 represents to receive according to the formed ofdm signal of OFDM transmission means of first and second embodiment and infers the formation of the receiving system of the impulse response in the time-domain of transmission path.
In Fig. 9, tuner 11 is transformed to Base Band to the frequency band of the ofdm signal that is received from radio bands.Fourier transform circuit 12 is transformed to frequency domain to the ofdm signal of Base Band from time-domain, as the vector string of each carrier wave of frequency domain and export.
Dispersion pilot extraction circuit 13 is extracted scattered pilot signal and necessary terminal pilot signal, band terminal pilot signal from the vector string of Fourier transform circuit 12 outputs.Vector generation circuit 14 takes place and the corresponding modulated complex vector C of being extracted by dispersion pilot extraction circuit 13 of scattered pilot signal, terminal pilot signal and band terminal pilot signal
K, n
Scattered pilot signal, terminal pilot signal and the band terminal pilot signal that division circuit 15 will be extracted by dispersion pilot extraction circuit 13 will be divided by with the complex vector that produces with vector generation circuit 14, infer and scattered pilot signal, transmission path characteristic that the terminal pilot signal is relevant with the band terminal pilot signal.16 pairs of interpolating circuits carry out interpolation by division circuit 15 is resulting with scattered pilot signal, transmission path characteristic that the terminal pilot signal is relevant with the band terminal pilot signal, infer and synchronous detection with the relevant transmission path characteristic of carrier wave of the transmission information signal of section.
Delay circuit 17 postpones a code element to the vector string of Fourier transform circuit 12 outputs.Select circuit 18 according to by the control information kind of the section of transmission in addition, synchronous detection with the situation of section under the output of selection interpolating circuit 16 export; Select the output of delay circuit 17 under with the situation of section and export in differential detection.
Division circuit 19 is divided by the vector string of Fourier transform circuit 12 outputs respectively with the output of selecting circuit 18.In division circuit 19, use in the section at synchronous detection, carry out division arithmetic with the transmission path characteristic relevant and carry out synchronous detection with the corresponding respectively carrier wave of being inferred by interpolating circuit 16,, carry out division arithmetic with the vector string of corresponding carrier wave respectively before the code element of delay circuit 17 outputs and carry out differential detection with in the section in differential detection.
The rectified signal that modulation system (QPSK, 16QAM, 64QAM, DBPSK, DQPSK, the DAPSK etc.) demodulation of demodulator circuit 20 when generating transmission information signal exported from division circuit 19, and obtain the digital information transmitted.
By above formation, can receive ofdm signal and carry out demodulation according to the OFDM transmission means described in first embodiment.Formation described below is the situation that receives ofdm signal and carry out demodulation according to the OFDM transmission means described in second embodiment.
At first, continuous pilot is extracted the vector string extraction continuous pilot signal of circuit 21 from Fourier transform circuit 12 outputs.At this moment, even mix under the situation about existing with section with section and differential detection,, then can extract continuous pilot signal all the time because synchronous detection must mix existence with the continuous pilot signal of section at least at synchronous detection.
Vector generation circuit 22 takes place and extracts the corresponding modulated complex vector C of continuous pilot signal that circuit 21 is extracted by continuous pilot
K, nDivision circuit 23 will extract the complex vector that continuous pilot signal that circuit 21 extracted and vector generation circuit 22 produce by continuous pilot and be divided by, and infer the transmission path characteristic relevant with continuous pilot signal.24 transmission path characteristic relevant with the continuous pilot signal that is drawn by division circuit 23 of inverse fourier transform circuit are time-domain from frequency domain transformation, and obtain the pusle response characteristics of transmission path.
As described above, formation according to the receiving system of present embodiment, in demodulator circuit 20, can realize high-quality demodulation by handle resulting filter effect by the interpolation of transmission path characteristic in section at synchronous detection, separate the demodulation that reception is moved in the variation of transferring to realize to be suitable for transmission path characteristic rapidly by differential between code element in section in differential detection.And, in inverse fourier transform circuit 24, can access the pusle response characteristics of the transmission path of not turning back.
As described above, orthogonal frequency-division multiplex transmission system of the present invention can have the differential detection section that is suitable for moving reception.At this moment, by having terminal pilot signal and band terminal pilot signal, can not damage the synchronous detection characteristic of the section that adjacent synchronous detection uses, and in each section the independent assortment synchronous detection with section and differential detection section, thus, can realize the flexible services state.
Can frequency of utilization the inverse fourier transform of configuration to being the continuous pilot signal of pulse type, during code element, obtain the pusle response characteristics of not turning back as required.
Like this, according to the present invention, a kind of OFDM mode and the dispensing device and the receiving system that are suitable for this mode are provided, this OFDM mode can partly import the modulation system that is suitable for moving reception while keeping all transmission capacities in the modulation of the carrier wave of transmitting digital information, and, configuration continuous pilot signal and can in the impulse response of the transmission path of inferring, not turning back by for example continuous pilot signal.