CN105991266B - Preamble symbol generation method, reception method, generation device, and reception device - Google Patents
Preamble symbol generation method, reception method, generation device, and reception device Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2689—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation
- H04L27/2692—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation with preamble design, i.e. with negotiation of the synchronisation sequence with transmitter or sequence linked to the algorithm used at the receiver
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J13/00—Code division multiplex systems
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- H04J13/0055—ZCZ [zero correlation zone]
- H04J13/0059—CAZAC [constant-amplitude and zero auto-correlation]
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Abstract
The invention provides a method and a device for generating and receiving a preamble symbol, and a device for generating and receiving the preamble symbol, wherein a time domain symbol has a first three-segment structure or a second three-segment structure or a free combination of a plurality of first three-segment structures and a plurality of second three-segment structures which are not arranged in sequence, so that coherent detection can be realized, the problem of performance reduction of incoherent detection is solved, and in addition, the predetermined sequence generation rule of a frequency domain main sequence comprises the following steps: giving different root values to the predetermined sequence to generate; and/or giving a preset same root value to generate, further performing cyclic shift generation on the generated sequence, and transmitting the signaling required by the system by using the obtained frequency domain main body sequence to improve the transmission efficiency.
Description
the present application is a divisional application of the original, and the title "preamble symbol generation method and reception method" was invented on application No. 201510052202.5 of the original, application date 2015, month 1 and 30.
Technical Field
The invention belongs to the technical field of transmission of broadcast communication systems, and particularly relates to a method for generating a preamble symbol, a method for receiving the preamble symbol and a corresponding device.
Background
At present, a method for implementing time synchronization between a transmitting end and a receiving end in an OFDM system is basically implemented based on preamble symbols. The preamble symbol is a symbol sequence known to both the transmitting end and the receiving end of the OFDM system, the preamble symbol marks the beginning of a physical frame (named as P1 symbol), only one P1 symbol or a plurality of P1 symbols occur consecutively in each physical frame, and the uses of the P1 symbol include:
1) enabling a receiving end to quickly detect whether a signal transmitted in a channel is an expected received signal;
2) providing basic transmission parameters (such as FFT point number, frame type information and the like) to enable a receiving end to carry out subsequent receiving processing;
3) Detecting initial carrier frequency deviation and timing error for achieving frequency and timing synchronization after compensation;
4) emergency alerts or broadcast system wake-up.
Generally, a preamble symbol includes a physical layer Format Control part (PHY Format Control, or PFC) and a physical layer Content Control part (PHY Content Control, or PCC), and is also generated by a CAB or BCA three-segment structure symbol for transmitting signaling information or further for transmitting frame Format parameters, however, in the prior art, the CAB or main body a of the BCA symbol only considers transmitting signaling by using different root values of a constant envelope zero autocorrelation CAZAC sequence in a frequency domain, which causes a system transmission efficiency to be insufficient, and does not consider transmitting required signaling by selecting the number of PFCCH symbols to adapt to system transmission needs.
Disclosure of Invention
the problem solved by the invention is that in the prior art, the signaling is transmitted by the time domain main body signal of the preamble symbol on the frequency domain only by using different root values of the constant envelope zero autocorrelation CAZAC sequence, so that the transmission efficiency of the system is insufficient, and the condition that the number of the time domain symbols of the format control part PFC is selected to transmit the required signaling to adapt to the transmission requirement of the system is not considered.
In order to solve the above problem, an embodiment of the present invention provides a method for generating a preamble symbol, where the preamble symbol includes a format control part PFC, and the method includes the following steps: generating a frequency domain subcarrier of the PFC (power factor correction) of the format control part according to a preset processing filling rule based on the frequency domain main body sequence ZC; performing inverse Fourier transform on the frequency domain subcarrier to obtain a time domain main signal of the PFC of the format control part corresponding to the frequency domain subcarrier; and generating a preamble symbol based on the time domain body signal, wherein the frequency domain body sequence ZC is generated according to a predetermined sequence generation rule based on a constant envelope zero autocorrelation sequence CAZAC, the predetermined sequence generation rule including: giving different root values to the constant envelope zero autocorrelation sequence CAZAC to generate; and/or giving the constant envelope zero autocorrelation sequence CAZAC the same root value to produce, further carry on cyclic shift to produce the sequence produced.
Optionally, the format control part PFC contains at least one time domain symbol having the following three-segment structure: a first three-stage structure: a time domain subject signal, a prefix generated based on a rear portion of the time domain subject signal, and a suffix generated based on the rear portion of the time domain subject signal; a second three-stage structure: a time domain subject signal, a prefix generated based on a back portion of the time domain subject signal, and a superpprefix generated based on the back portion of the time domain subject signal, wherein each time domain symbol carried for transmission by a frequency domain subcarrier comprises: a first three-stage structure; or a second three-stage structure; or a first three-segment structure and a second three-segment structure which are not arranged in sequence.
optionally, the frequency domain body sequence ZC is generated based on one or more constant-envelope zero-autocorrelation sequences CAZAC, the frequency domain body sequence ZC having a predetermined sequence length NZC。
Alternatively, when generating based on a constant-envelope zero-autocorrelation sequence CAZAC, wherein reference is made to a predetermined sequence length N that the constant-envelope zero-autocorrelation sequence CAZAC hasZCdetermining the number of roots in the predetermined sequence generation rule and/or determining the number of bits to perform the cyclic shift.
Alternatively, when generated based on a plurality of constant-envelope zero-autocorrelation sequences CAZAC, each constant-envelope zero-autocorrelation sequence CAZAC has a corresponding sub-sequence length LMWherein each constant envelope zero auto-correlation sequence CAZAC is generated according to a predetermined sequence generation rule to have a corresponding sub-sequence length LMA subsequence of (a); and splicing the plurality of subsequences to have a predetermined sequence length NZCWith reference to the corresponding sub-sequence length L of each constant envelope zero autocorrelation sequence CAZACMdetermining the number of roots in the predetermined sequence generation rule and/or determining the number of bits to perform the cyclic shift.
Optionally, the frequency domain subject sequence ZC has a predetermined sequence length NZCnot greater than the Fourier transform length N that the time domain subject signal hasFFTin the predetermined processing filling rule, at least: mapping a frequency domain subject sequence ZC to have a predetermined sequence length NZCthe direct current sub-carrier, the positive frequency sub-carrier and the negative frequency sub-carrier; with reference to the Fourier transform length NFFTthe outer edges of the positive frequency subcarriers and the negative frequency subcarriers of the frequency domain bulk sequence ZC are filled with a predetermined number of virtual subcarriers, respectively.
Optionally, in the predetermined processing padding rule, for the frequency domain subject sequence ZC, further comprising: PN modulation is performed and mapping is performed again.
Alternatively, the step of performing cyclic shift in the predetermined sequence generation rule is performed before or after the step of performing PN modulation in the predetermined processing padding rule.
optionally, information is transmitted using the root value in the first time domain symbol and the initial phase of the PN sequence used for PN modulation.
Optionally, in the predetermined processing padding rule, for the frequency domain subject sequence ZC, two steps are further included in no order: carrying out PN modulation; and frequency domain interleaving is performed, thereby performing mapping again.
Optionally, when the frequency domain bulk sequence ZC is generated based on a plurality of constant-envelope zero-autocorrelation sequences CAZAC, the predetermined processing padding rule at least comprises a step of performing frequency domain interleaving.
Optionally, the time domain body signal is defined as a first part, the time domain body signal part for postfix or super-prefix is defined as a second part, and the emergency broadcast is identified by a different starting point for selecting the second part from the first part.
Optionally, the frequency domain subcarrier uses the frequency domain subject sequence ZC for signaling transmission, and if a first time domain symbol of the at least one time domain symbol uses a pre-known frequency domain subject sequence ZC, the frequency domain subject sequence ZC is not used for signaling transmission.
Optionally, the preamble symbol is located in a physical frame, and the frequency domain subcarrier utilization frequency domain body sequence ZC is further used for indicating a frame format parameter of the physical frame.
the embodiment of the invention also provides a method for receiving the preamble symbol, which is characterized by comprising the following steps: processing the received physical frame to obtain a baseband signal; judging whether the baseband signal has the preamble symbol which is expected to be received and generated in the generation method; and if so, determining the position of the preamble symbol in the physical frame and decoding the signaling information carried by the preamble symbol.
optionally, when the first time domain symbol of the format control part PFC does not transmit the signaling as the known information, performing a difference operation on the first time domain symbol, performing a difference operation on a time domain sequence corresponding to the known information, performing cross-correlation on the time domain sequence and the time domain sequence to obtain a cross-correlation value, and performing peak detection based on a peak obtained by one or more obtained cross-correlation values to determine whether the expected preamble symbol exists.
Optionally, the integer frequency offset estimation and the initial channel estimation are performed by using the first time domain symbol of the format control part PFC.
Optionally, when it is detected that the format control part PFC has a three-segment structure, a delay sliding autocorrelation is performed by using a specific delay relationship of the first three-segment structure and/or the second three-segment structure to obtain a correlation value, and after a specific mathematical operation is performed on the correlation value, a peak value obtained is subjected to peak value detection to determine whether a preamble symbol expected to be received exists.
Optionally, in the step of determining the position of the preamble symbol in the physical frame and solving the signaling information carried by the preamble symbol, if there is a preamble symbol expected to be received, the position of the preamble symbol in the physical frame is determined according to a larger part or a maximum value of the peak value.
Optionally, after determining the position of the preamble symbol in the physical frame, the fractional frequency offset estimation is performed by using the result of the peak detection.
Optionally, in the step of solving the signaling information carried by the preamble symbol, the method includes: and solving signaling information carried by the preamble symbol by using all or part of the time domain waveform of the preamble symbol and/or a frequency domain signal obtained by performing Fourier transform on all or part of the time domain waveform of the preamble symbol.
optionally, in the step of decoding the signaling information carried by the preamble symbol by using the frequency domain signal, if the signaling sequence is modulated by the PN, the PN demodulation operation needs to be performed first, and then the ZC sequence signaling analysis needs to be performed.
optionally, in the step of solving the signaling information carried by the preamble symbol by using the frequency domain signal, the signaling is resolved by using a signaling sequence set generated by all possible different root values and/or different cyclic shift values of the frequency domain main body sequence ZC sent by the sending end.
optionally, if the signaling subcarrier of each format control part PFC includes more than one frequency domain main sequence ZC and performs PN modulation and frequency domain interleaving, the receiving end performs corresponding frequency domain deinterleaving, demodulates PN, and then performs signaling analysis of the frequency domain main sequence ZC after obtaining the frequency domain effective subcarrier, wherein, if the PN modulation is before the frequency domain interleaving, the frequency domain deinterleaving is performed before the PN modulation is performed; if the PN modulation is after the frequency domain interleaving, the PN is demodulated firstly and then the frequency domain de-interleaving is performed, or the frequency domain de-interleaving is performed firstly and then the PN is demodulated, and the demodulated PN sequence is the PN sequence of the original PN after the de-interleaving is performed.
Optionally, after decoding of a first symbol in the format control part PFC is completed, demodulating, decoding and analyzing a plurality of subsequent symbols, and after decoding of a symbol of the last format control part PFC is completed, performing channel estimation again in a time domain/frequency domain by using the obtained decoding information as transmission information, and performing a certain specific operation with a previous channel estimation result to obtain a new channel estimation result for channel estimation of signaling analysis of a next symbol.
The embodiment of the present invention further provides a device for generating a preamble symbol, which is characterized by comprising: a body sequence generation unit for generating a frequency domain body sequence ZC; the frequency domain subcarrier generating unit is used for generating frequency domain subcarriers by filling according to a preset processing filling rule based on the frequency domain main body sequence ZC; the frequency domain transformation unit is used for carrying out inverse Fourier transformation on the obtained frequency domain subcarriers to obtain time domain main signals; and a time domain processing unit which obtains the preamble symbol based on the time domain subject signal, wherein the subject sequence generating unit includes a processing generating module which is configured to generate a frequency domain subject sequence ZC based on a constant envelope zero autocorrelation sequence CAZAC according to a predetermined sequence generating rule which includes: giving different root values to the constant envelope zero autocorrelation sequence CAZAC to generate; and/or giving the constant envelope zero autocorrelation sequence CAZAC the same root value to produce, further carry on cyclic shift to produce the sequence produced.
The embodiment of the present invention further provides a device for receiving a preamble symbol, which is characterized by comprising: the baseband processing unit is used for processing the received physical frame to obtain a baseband signal; a preamble symbol judging unit for judging whether the baseband signal has the preamble symbol expected to be received and generated by the generating device; and the signaling analysis unit is used for determining the position of the preamble symbol in the physical frame and solving the signaling information carried by the preamble symbol under the condition that the judgment result of the preamble symbol judgment unit is yes.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
According to the preamble symbol generation method and reception method, the preamble symbol generation device, and the reception device provided in the embodiments of the present invention, the frequency domain bulk sequence ZC is generated based on the constant envelope zero autocorrelation sequence CAZAC according to a predetermined sequence generation rule including: giving different root values to the constant envelope zero autocorrelation sequence CAZAC to generate; and/or giving the constant envelope zero autocorrelation sequence CAZAC the same root value to produce, further carry on the cyclic shift to produce the sequence produced, utilize frequency domain body sequence ZC obtained to transmit the system required signalling, raise the transmission efficiency, further, the first time domain symbol of the format control channel part in the leading symbol can be a known symbol, is used for the initial channel estimation used for coherent detection, can choose the number of symbols in PFC to transmit the required signalling flexibly according to the system need at the same time.
Drawings
fig. 1 is a flowchart illustrating an embodiment of a preamble symbol generation method according to the present invention;
FIG. 2 is a schematic diagram of a time domain structure of a physical frame in an embodiment of the present invention;
Fig. 3 is a schematic diagram of a physical frame structure including a format control part and a content control part in an embodiment of the present invention;
FIG. 4 is a frequency domain diagram of a format control portion in an embodiment of the invention;
FIG. 5 is a schematic illustration of a first three-stage structure in an embodiment of the invention;
FIG. 6 is a schematic illustration of a second three-segment structure in an embodiment of the invention; and
fig. 7 is a flowchart illustrating an embodiment of a preamble symbol receiving method according to the present invention.
Detailed Description
The inventor finds that in the prior art, the time domain main body signal of the preamble symbol only utilizes different root values of the constant envelope zero autocorrelation CAZAC sequence to transmit signaling on the frequency domain, so that the system transmission efficiency is insufficient, and also does not consider the problem that the number of time domain symbols of the format control part PFC is selected to transmit the required signaling to adapt to the system transmission requirement.
In view of the above problems, the present inventors have studied and provided a preamble symbol generation method and reception method, and a preamble symbol generation device and reception device, in which a frequency domain bulk sequence ZC is generated based on a constant envelope zero autocorrelation sequence CAZAC according to a predetermined sequence generation rule including: giving different root values to the constant envelope zero autocorrelation sequence CAZAC to generate; and/or giving the constant envelope zero autocorrelation sequence CAZAC the same root value to produce, further carry on the cyclic shift to produce the sequence produced, utilize frequency domain body sequence ZC obtained to transmit the system required signalling, raise the transmission efficiency, further, the first time domain symbol of the format control channel part in the leading symbol can be a known symbol, is used for the initial channel estimation used for coherent detection, can choose the number of symbols in PFC to transmit the required signalling flexibly according to the system need at the same time.
in order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
fig. 1 is a flowchart illustrating a method for generating preamble symbols according to an embodiment of the present invention. As shown in fig. 1, the method for generating a preamble symbol in this embodiment, where the preamble symbol includes a format control part PFC, includes the following steps:
Step S1-1: generating a frequency domain subcarrier of the PFC (power factor correction) of the format control part according to a preset processing filling rule based on the frequency domain main body sequence ZC;
step S1-2: performing inverse Fourier transform on the frequency domain subcarrier to obtain a time domain main signal of the PFC of the format control part corresponding to the frequency domain subcarrier; and
Step S1-3: generating a preamble symbol based on the time domain subject signal,
wherein the frequency domain bulk sequence ZC is generated according to a predetermined sequence generation rule based on a constant envelope zero autocorrelation sequence CAZAC, the predetermined sequence generation rule including: giving different root values to the constant envelope zero autocorrelation sequence CAZAC to generate; and/or giving the constant envelope zero autocorrelation sequence CAZAC the same root value to produce, further carry on cyclic shift to produce the sequence produced.
Fig. 2 is a schematic time domain structure diagram of a physical frame in an embodiment of the present invention. As shown in fig. 2, the present implementation discloses a frame structure, and two physical frames are shown in fig. 2. Each physical frame of the frame structure contains a preamble symbol and a data region, respectively, wherein the preamble symbol precedes the data region.
Fig. 3 is a schematic diagram of a physical frame structure including a format control portion and a content control portion in an embodiment of the present invention.
As shown in fig. 3, the physical frame structure includes a preamble symbol and a data area, wherein the preamble symbol includes: the part PFC and the part PCC are controlled by the physical layer format.
the PFC consists of one or more OFDM time domain symbols (indicated by the hatched box in the figure), each of which is the same size.
FIG. 5 is a schematic illustration of a first three-stage structure in an embodiment of the invention; and FIG. 6 is a schematic illustration of a second three-stage structure in an embodiment of the present invention.
the format control part PFC contains at least one time domain symbol having the following three-segment structure: a first three-stage structure: a time domain subject signal, a prefix generated based on a rear portion of the time domain subject signal, and a suffix generated based on the rear portion of the time domain subject signal; a second three-stage structure: the apparatus generally includes a time domain body signal, a prefix generated based on a back portion of the time domain body signal, and a prefix generated based on the back portion of the time domain body signal.
a time domain main body signal (denoted by a in the figure) is used as a first part, a part is taken out from the tail end of the first part according to a preset acquisition rule, the first part is processed according to a first preset processing rule and copied to the front part of the first part to generate a third part (denoted by C in the figure) as a prefix, meanwhile, a part is taken out from the rear part of the first part according to a preset acquisition rule, the second part is processed according to a second preset processing rule and copied to the rear part of the first part or processed and copied to the front part of the prefix to generate a second part (denoted by B in the figure) as a suffix or a super prefix respectively, and thus, a first three-segment structure (CAB structure) with B as a suffix and a second three-segment structure (BCA structure) with B as a super prefix shown in fig. 5 are respectively generated, and the second three-segment structure (BCA structure) shown in fig..
As shown in fig. 5 and fig. 6, each OFDM time domain symbol in the time domain includes a third part (C segment), which is a ZC sequence that is a specific frequency domain body sequence obtained by IFFT inverse fourier transform of 2048 points, and a first part (a segment), which is a prefix that is a latter half of the a segment, and a second part (B segment), which is a suffix or prefix that is a modulation frequency offset of the a segment.
Wherein each time domain symbol that is transmitted by the frequency domain subcarrier bearer comprises: a first three-stage structure; or a second three-stage structure; or a first three-segment structure and a second three-segment structure which are not arranged in sequence. That is, PFCs are made up of a random combination of several structures of C-A-B or B-C-A. Such as C-A-B B-C-A C-A-B B-C-A, and C-A-B B-C-AB-C-A B-C-A. Then, the first three-segment structure or the second three-segment structure is combined with the effective sub-carrier wave on the frequency domain in fig. 1 to use different root value generation sequences of the CAZAC sequence and/or cyclic shift sequences of the sequences generated by each root value to transmit signaling, so that the C-A-B and B-C-A which are freely combined can be transmitted for multiple times.
In this embodiment, the segment C in the three-segment structure is a direct copy of the segment a, the segment B is a modulation signal segment of the segment a, and the data range of the segment B does not exceed the data range of the segment C, that is, the range of the portion a selected to the modulation signal segment B does not exceed the range of the portion a intercepted as the prefix C. Preferably, the sum of the length of B and the length of C is the length of a.
Let NALet Len be the length of ACis the length of C, LenBis the length of the modulation signal segment B. Let the sampling point number of A be 0,1, … NALet N1 be the sample point number selected to copy to the first part a corresponding to the start of the second part B, and N2 be the sample point number selected to copy to the first part a corresponding to the end of the second part B. Wherein,
N2＝N1+LenB-1
Generally, the modulation applied to the second part B segment is modulation frequency offset, modulation M sequence or other sequences, etc., in this implementation, taking modulation frequency offset as an example, if P1_ a (t) is a time domain expression of a, then the time domain expression of the preamble symbol with the first three-segment structure is
wherein, the modulation frequency deviation value fSHcan be selected as the frequency domain subcarrier interval corresponding to the time domain OFDM symbol, namely 1/NAT, where T is the sampling period, NAis the length of a time domain OFDM symbol, e.g., NAIs 1024, take fSH1/1024T. And the modulation frequency offset can be arbitrarily selected to be an initial phase, in order to make the correlation peak sharp, fSHCan also be selected to be 1/(Len)BT)。
In the structure of B-C-A, the modulation frequency deviation value is just opposite to that of the structure of C-A-B, and the modulation can be arbitrarily selected as an initial phase. The following is a time domain expression of a preamble symbol having a second three-segment structure:
Assuming that N1 of the C-A-B structure is N1_1 and N1 of the B-C-A symbol is N1_2, N1_1+ N1_2 is required to be 2NA-(LenB+Lenc). And if the modulation applied to the B segment is a modulation frequency offset, the frequency offset value is the opposite.
The symbol of C-A-B structure is represented by the symbol No. 1, and the symbol of B-C-A structure is represented by the symbol No. 2. Then, assuming that P1_ A (t) is the time domain expression of A1 and P2_ A (t) is the time domain expression of A2, the time domain expression of the C-A-B three-segment structure is
the time domain expression of the three-section structure of B-C-A is as follows
wherein, the first three-segment structure and the second three-segment structure which are not arranged in sequence can respectively form the first enhanced leading symbol and the second enhanced leading symbol according to the difference in sequence.
then, the time domain expression of the first enhanced preamble symbol is:
The time domain expression of the second kind of enhanced preamble symbol is:
As a specific example, NA2048, let LenCis 520, LenB＝504,N1_1＝1544， N1_2＝1528。
Further, the emergency broadcast system is identified by selecting a different starting point for the second part B from the first part a, i.e. by selecting a different N1, or N1_1 and N1_2, by copying to the starting point of the B segment. A symbol of a three-segment structure such as C-a-B, N1_ 1-1544 identifies a general system, and N1_ 1-1528 identifies an emergency broadcast system. For another example, in the notation of the three-segment structure of B-C-a, N1_2 ═ 1528 identifies a general system, and N1_2 ═ 1544 identifies an emergency broadcast system.
Fig. 4 is a frequency domain diagram of a format control portion in an embodiment of the invention.
predetermined sequence length N that frequency domain subject sequence ZC hasZCNot greater than the Fourier transform length N that the time domain subject signal hasFFTin the predetermined processing filling rule, at least: mapping a frequency domain subject sequence ZC to have a predetermined sequence length NZCThe direct current sub-carrier, the positive frequency sub-carrier and the negative frequency sub-carrier; with reference to the Fourier transform length NFFTThe outer edges of the positive frequency subcarriers and the negative frequency subcarriers of the frequency domain bulk sequence ZC are filled with a predetermined number of virtual subcarriers, respectively.
As shown in fig. 4, in the frequency domain subcarrier generation process of each time domain symbol of the PFC, in particular, a certain ZC sequence is obtained by transform padding by a predetermined processing padding rule as follows: first, N is generatedZCA Zadoff-Chu sequence (abbreviated as ZC sequence) with the length, then a PN sequence with the same length can be selected to modulate the ZC sequence to obtain a ZC _ M sequence, the ZC _ M sequence is divided into two parts, the left part has the length ofmapped to the negative frequency part, the right half length isMapping to a positive frequency part, NZCA certain natural number can be selected, the length of the A section FFT is not exceeded, and the maximum value in the example is 1499; in addition, at the edge of negative frequency, complementnumber of zeros, and at the edges of positive frequencies, complementthe number of zeros, being virtual subcarriers; thus, the specific sequence is composed ofThe number of the zero lines is zero,a number of PN modulated ZC sequences, 1 dc subcarrier,a PN modulated ZC sequence andEach zero is composed sequentially; number of effective subcarriers is NZC+1. Note in particular that the PFC may consist of one or more OFDM symbols.
The ZC sequence may be generated from different root values of CAZAC sequences, or may be obtained by cyclically shifting a sequence generated from the same root value. For example,Several different q's may be selected, and for each sequence generated by q, different cyclic shifts may be performed to obtain more sequences.
For example, taking 256 roots q to obtain 256 sequences, and setting a shift value of 1024, each sequence may be shifted by 0-1023, so that a total of 8+ 10-18-bit signaling may be transmitted.
further, the cyclic shift can be performed before the ZC sequence modulates the PN sequence or after the ZC sequence modulates the PN sequence.
in this embodiment, the frequency domain subcarrier uses the frequency domain main body sequence ZC for signaling transmission, and if a first time domain OFDM symbol of the at least one time domain OFDM symbol uses a pre-known frequency domain main body sequence ZC, the frequency domain main body sequence ZC is not used for signaling transmission.
these signalling are mapped to the bit field and not only used for transmitting signalling with the frequency domain body sequence ZC, but further alternatively, frame format parameters (e.g. number of frames, frame length, bandwidth of PCC symbols, bandwidth of data region, FFT size and guard interval length of PCC symbols, PCC modulation and coding parameters) of the physical frame may also be indicated simultaneously with the frequency domain body sequence ZC.
For the first OFDM symbol, a certain ZC sequence known in advance is usually adopted, that is, in the case of no signaling, the signaling is transmitted by the subsequent PFCCH, and the ZC sequence used by the last OFDM symbol is 180 degrees out of phase with the ZC sequence used by the first OFDM symbol, which is used to indicate the last OFDM symbol of the PFC.
the ZC sequence used for the first OFDM symbol in the PFC is generally a root sequence with a certain length and without cyclic shift, and at this length, the ZC sequence has a set, so that the ZC sequence in the set is selected by the present invention, which may indicate certain information, such as a version number or indicate a type or mode of a service transmitted in a data frame; in addition, the initial phase of the PN also has some signaling capability, such as indicating a version number. That is, certain information is transmitted using the root value in the first time domain symbol and the initial phase of the PN sequence for PN modulation.
in this embodiment, the frequency domain subject sequence ZC may be generated based on one or more constant-envelope zero-autocorrelation sequences CAZAC, the frequency domain subject sequence ZC having a predetermined sequence length NZC。
As a specific example, as illustrated in fig. 4, when the constant-envelope zero-autocorrelation sequence CAZAC is generated, the predetermined sequence length N of the constant-envelope zero-autocorrelation sequence CAZAC is referred toZCDetermining the number of roots in the predetermined sequence generation rule and/or determining the number of bits to perform the cyclic shift.
Another specific example is given below to illustrate that when generated based on a plurality of constant-envelope zero-autocorrelation sequences CAZAC, each constant-envelope zero-autocorrelation sequence CAZAC has a corresponding sub-sequence length LMWherein each constant envelope zero auto-correlation sequence CAZAC is generated according to a predetermined sequence generation rule with a corresponding sub-sequenceColumn length LMa subsequence of (a); and splicing the plurality of subsequences to have a predetermined sequence length NZCWith reference to the corresponding sub-sequence length L of each constant envelope zero autocorrelation sequence CAZACMDetermining the number of roots in the predetermined sequence generation rule and/or determining the number of bits to perform the cyclic shift.
Specifically, the frequency domain effective subcarriers may be generated by a plurality of (i.e., M) CAZAC sequences, where the lengths of the M CAZAC sequences are L1,L2,...LMAnd satisfythe generation method of each CAZAC sequence is the same as the above method, only one step is added, and after M CAZAC sequences are generated, the M CAZAC sequences are spliced into a sequence with the length of NZCthe selected ZC _ M is modulated by PN sequence to form new ZC _ I, which is then interleaved in frequency domain to fill in the same sub-carrier position and has the length of the left half partMapped to the negative frequency part, the right half length isMapping to a positive frequency part, NZCA certain natural number can be selected, the length of the A section FFT is not exceeded, and the maximum value in the example is 1499; in addition, at the edge of negative frequency, complementnumber of zeros, and at the edges of positive frequencies, complementthe number of zeros, being virtual subcarriers; thus, the specific sequence is composed ofThe number of the zero lines is zero,a number of PN modulated ZC sequences, 1 dc subcarrier,A PN modulated ZC sequence andeach zero is composed sequentially; the step of modulating PN can also be carried out after frequency domain interleaving, and the sequence is not limited. However, when the frequency domain bulk sequence ZC is generated based on a plurality of constant-envelope zero autocorrelation sequences CAZAC, the predetermined processing padding rule at least includes a step of performing frequency domain interleaving, which is necessary.
fig. 7 is a flowchart illustrating an embodiment of a preamble symbol receiving method according to the present invention.
As shown in fig. 7, the preamble symbol receiving method in this embodiment includes the following steps:
step S2-1: processing the received physical frame to obtain a baseband signal;
step S2-2: judging whether a pilot symbol expected to be received and generated by the generation method in the figure 1 exists in the baseband signal or not;
step S2-3: and if so, determining the position of the preamble symbol in the physical frame and decoding the signaling information carried by the preamble symbol.
when the first symbol of the PFC does not transmit a signaling and is a known signal, step S2-2 may perform a difference operation on the first symbol of the PFC, perform a difference operation on a time domain signal corresponding to the known information, perform a cross-correlation on the time domain signal and the time domain signal, and detect whether there is an expected preamble symbol based on a peak value obtained by one or more cross-correlation values.
when the PFC has a structure of C-A-B or B-C-A, delay sliding autocorrelation is carried out by utilizing a specific delay relation of C-A-B and/or B-C-A to obtain a correlation value, and after specific mathematical operation is carried out on the basis of the correlation value, a peak value is used for detecting whether a preamble symbol expected to be received exists or not.
In step S2-3, specifically, if there is a preamble symbol expected to be received, the position of the preamble symbol in the physical frame is determined according to the part of the value or the maximum value with the largest peak value.
After the position of the preamble symbol in the physical frame is determined, decimal frequency offset estimation can be performed by using the result of peak detection.
In addition, the first symbol of the PFC may be utilized for the offset estimation and the initial channel estimation.
the decoding of the signaling information carried by the preamble symbol includes the following steps: and solving signaling information carried by the preamble symbol by using all or part of the time domain waveform of the preamble symbol and/or a frequency domain signal obtained by performing Fourier transform on all or part of the time domain waveform of the preamble symbol.
For example, the length N of the A segment position corresponding to each received symbol of the PFC partFFTAfter FFT operation of corresponding length is carried out on the time domain received data, zero carrier is removed, the received frequency domain signaling subcarrier is taken out according to the effective signaling subcarrier position, and signaling analysis is carried out by utilizing the frequency domain signaling subcarrier
If the signaling sequence is modulated by PN, the PN demodulation operation is needed first, and then the ZC sequence signaling analysis is needed.
The frequency domain decoding function is accomplished, for example, by performing specific mathematical operations on the frequency domain signaling subcarriers with the channel estimates and the known set of signaling sequences. The specific mathematical operation may be maximum likelihood correlation, or the channel estimation value is firstly carried out on the frequency domain signaling subcarrier, then the correlation operation is carried out on the frequency domain signaling subcarrier and the signaling sequence set, and the largest correlation value is selected as the decoding result.
If the signaling subcarrier of each symbol of the PFC is formed by modulating PN by more than one ZC sequence and interleaving in the frequency domain, after the receiving end obtains the effective subcarrier in the frequency domain, corresponding frequency domain de-interleaving operation is carried out, PN demodulation operation is carried out, and then ZC sequence signaling analysis is carried out. If the modulated PN is before the frequency domain interleaving, the frequency domain de-interleaving is firstly carried out, and then the PN is demodulated. If the modulated PN is interleaved in the frequency domain, the PN is demodulated firstly and then the frequency domain de-interleaving is carried out, or the frequency domain de-interleaving is carried out firstly and then the PN is demodulated, but the demodulated PN sequence is the PN sequence of the original PN after the de-interleaving is carried out.
further, after the previous symbol of the PFC is decoded, assuming that the decoding is correct, the channel estimation is performed again in the time domain/frequency domain using the previous decoded information as the transmission information, and a certain specific operation is performed with the previous channel estimation result to obtain a new channel estimation result for the channel estimation of the signaling analysis of the next symbol.
not shown in the figure, an embodiment of the present invention further provides a device for generating a preamble symbol, where the device includes: a body sequence generation unit for generating a frequency domain body sequence ZC; the frequency domain subcarrier generating unit is used for generating frequency domain subcarriers by filling according to a preset processing filling rule based on the frequency domain main body sequence ZC; the frequency domain transformation unit is used for carrying out inverse Fourier transformation on the obtained frequency domain subcarriers to obtain time domain main signals; and a time domain processing unit which obtains the preamble symbol based on the time domain subject signal.
Wherein the subject sequence generating unit includes a processing generation module configured to generate a frequency domain subject sequence ZC based on a constant envelope zero autocorrelation sequence CAZAC according to a predetermined sequence generation rule including: giving different root values to the constant envelope zero autocorrelation sequence CAZAC to generate; and/or giving the constant envelope zero autocorrelation sequence CAZAC the same root value to produce, further carry on cyclic shift to produce the sequence produced.
Not shown in the figure, an embodiment of the present invention further provides a receiving apparatus for a preamble symbol, where the receiving apparatus includes: the baseband processing unit is used for processing the received physical frame to obtain a baseband signal; a preamble symbol judging unit for judging whether the baseband signal has the preamble symbol expected to be received and generated by the generating device; and the signaling analysis unit is used for determining the position of the preamble symbol in the physical frame and solving the signaling information carried by the preamble symbol under the condition that the judgment result of the preamble symbol judgment unit is yes.
The preamble symbol generating device and the receiving device provided in this embodiment correspond to the preamble symbol generating method and the receiving method in the foregoing embodiments, respectively, so that the structure and technical elements of the device can be formed by corresponding conversion of the generating method, and are omitted for description.
Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications of the present invention without departing from the spirit and scope of the present invention by using the methods and technical contents disclosed above.
Claims (28)
1. a generation method of a leading symbol, the leading symbol is used for realizing time synchronization of a sending end and a receiving end in an OFDM system, characterized by comprising the following steps:
generating a frequency domain main body sequence based on one or more constant-envelope zero autocorrelation sequences, generating frequency domain subcarriers based on the frequency domain main body sequence, and performing inverse Fourier transform on the frequency domain subcarriers to obtain a time domain main body signal;
Generating a time domain symbol having the following three-segment structure based on the time domain subject signal; and
Generating a preamble symbol based on at least one of the time domain symbols,
Wherein a first of the three-segment structures comprises: selecting a part of generated prefixes at the tail ends of the time domain main signals and selecting a part of generated suffixes in the prefix range based on the time domain main signals;
A second one of the three-segment structures comprises: the time domain body signal, a part of the generated prefix selected at the tail end of the time domain body signal and a part of the generated prefix selected in the prefix range based on the time domain body signal,
Each of the time domain symbols has:
a first of said three-segment structures; or
A second of said three-segment structures; or
A plurality of first three-segment structures and/or a plurality of second three-segment structures which are not arranged in sequence are freely combined.
2. A preamble symbol generation method as claimed in claim 1,
Wherein the time domain body signal is defined as a first portion, the time domain body signal portion for the suffix or the super-prefix is defined as a second portion, the time domain body signal portion for the prefix is defined as a third portion,
The third part is obtained based on a part of the first part by direct copying, and the second part is obtained based on a part of the modulation frequency offset of the first part.
3. A preamble symbol generation method as claimed in claim 2,
wherein the length of the first portion is set to NASetting the length of the second part as LenBSetting the length of the third portion to LenC，
Selecting the starting point of the second part in the first three-segment structure, setting the first sampling point number of the starting point of the second part corresponding to the first part as N1_1, selecting the starting point of the second part in the second three-segment structure, and setting the second sampling point number of the starting point of the second part corresponding to the first part as N1_2, and satisfying the following formula:
N1_1+N1_2＝2NA-(LenB+Lenc)，
modulation frequency offset value fSHThe time domain symbol may be selected to correspond to a frequency domain subcarrier spacing of 1/NAand T, randomly selecting the modulation initial phase, wherein T is a sampling period.
4. A preamble symbol generation method as claimed in claim 3,
wherein, for each first of said three-segment structures and each second of said three-segment structures,
NA2048, let LenCvalue 520 LenBThe value 504 is taken, the first sampling point number N1_1 is 1544, the second sampling point number N1_2 is 1528,
the modulation frequency offset value fSHAnd may be selected to be 1/(2048T).
5. A preamble symbol generation method as claimed in claim 2,
Wherein an emergency broadcast is identified with a different starting point from which the second portion was selected from the first portion.
6. a generation method of a leading symbol, the leading symbol is used for realizing time synchronization of a sending end and a receiving end in an OFDM system, characterized by comprising the following steps:
Generating frequency domain subcarriers based on a frequency domain subject sequence, the frequency domain subject sequence being generated based on one or more constant-envelope zero auto-correlation sequences;
Performing inverse Fourier transform on the frequency domain subcarriers to obtain time domain main body signals; and
Generating the preamble symbol based on at least one time domain symbol formed by the time domain body signal,
Wherein the frequency domain subject sequence is generated according to a predetermined sequence generation rule, the predetermined sequence generation rule comprising:
Giving different root values to the predetermined sequence to generate; and/or
Giving the same root value to a preset sequence to generate, and further performing cyclic shift on the generated sequence to generate;
The time domain symbol has the following three-segment structure:
A first of the three-segment structures comprises: selecting a part of generated prefixes at the tail ends of the time domain main signals and selecting a part of generated suffixes in the prefix range based on the time domain main signals;
A second one of the three-segment structures comprises: the time domain body signal, a part of the generated prefix selected at the tail end of the time domain body signal and a part of the generated prefix selected in the prefix range based on the time domain body signal,
Wherein each of the time domain symbols transmitted over the frequency domain subcarriers comprises:
a first of said three-segment structures; or
A second of said three-segment structures; or
A plurality of first three-segment structures and/or a plurality of second three-segment structures which are not arranged in sequence are freely combined.
7. a method for generating preamble symbols according to claim 6, wherein:
And generating the frequency domain main body sequence based on the constant envelope zero autocorrelation sequence by adopting the constant envelope zero autocorrelation sequence in the predetermined sequence generation rule.
8. a method for generating preamble symbols according to claim 6, wherein:
wherein the frequency domain body sequence is generated based on one or more constant-envelope zero auto-correlation sequences, the frequency domain body sequence having a predetermined sequence length NZC。
9. a preamble symbol generation method according to claim 8, characterized in that:
when generated based on a plurality of constant-envelope zero-autocorrelation sequences, each constant-envelope zero-autocorrelation sequence has a corresponding subsequence length LM，
wherein, for each constant envelope zero auto-correlation sequence, a constant envelope zero auto-correlation sequence with a corresponding sub-sequence length L is generated according to the predetermined sequence generation ruleMa subsequence of (a); and
Splicing a plurality of the subsequences to have the predetermined sequenceLength NZCthe frequency domain subject sequence of (a).
10. A method for generating preamble symbols according to claim 6, wherein:
The frequency domain subject sequence has a predetermined sequence length NZCNot greater than the Fourier transform length N that the time domain subject signal hasFFT，
the frequency domain subject sequence generates the frequency domain subcarriers according to a predetermined processing padding rule, which at least includes:
mapping the frequency domain subject sequence to have a predetermined sequence length NZCPositive frequency subcarriers and negative frequency subcarriers;
referring to the Fourier transform length NFFTAnd filling a preset number of virtual subcarriers and direct current subcarriers at the outer edges of the positive frequency subcarriers and the negative frequency subcarriers respectively.
11. a preamble symbol generation method according to claim 10, characterized in that:
In the predetermined processing filling rule, for the frequency domain subject sequence, further comprising:
PN modulation is performed to thereby perform the mapping again.
12. a preamble symbol generation method as claimed in claim 11,
Wherein the step of performing the cyclic shift in the predetermined sequence generation rule is performed before or after performing PN modulation.
13. a preamble symbol generation method as claimed in claim 11,
And transmitting information by using the root value in the frequency domain main body sequence corresponding to the first time domain main body signal and the initial phase of the PN sequence for PN modulation.
14. A preamble symbol generation method as claimed in claim 6,
wherein the frequency domain subcarriers transmit signaling using the frequency domain body sequence,
If the first time domain main body signal in the at least one time domain main body signal adopts the pre-known frequency domain main body sequence, the frequency domain main body sequence is not used for signaling transmission.
15. the preamble symbol generation method of claim 14,
Wherein the preamble symbol is located in a physical frame, and the signaling transmitted using the frequency domain body sequence includes a frame format parameter for indicating the physical frame and/or for indicating emergency broadcast content.
16. A receiving method of a leading symbol is provided, the leading symbol is used for realizing time synchronization of a sending end and a receiving end in an OFDM system, and the method is characterized by comprising the following steps:
Processing the received physical frame to obtain a baseband signal;
Judging whether a pilot symbol expected to be received exists in the baseband signal or not;
determining the position of the received preamble symbol in a physical frame and solving signaling information carried by the preamble symbol;
The preamble symbol is generated based on at least one time domain symbol formed by a time domain main signal, a frequency domain main sequence is generated based on one or more constant envelope zero autocorrelation sequences, a frequency domain subcarrier is generated based on the frequency domain main sequence, the frequency domain subcarrier is subjected to inverse Fourier transform to obtain the time domain main signal, and the time domain symbol has the following three-section structure:
A first of the three-segment structures comprises: selecting a part of generated prefixes at the tail ends of the time domain main signals and selecting a part of generated suffixes in the prefix range based on the time domain main signals;
A second one of the three-segment structures comprises: the time domain body signal, a part of the generated prefix selected at the tail end of the time domain body signal and a part of the generated prefix selected in the prefix range based on the time domain body signal,
wherein each of the time domain symbols transmitted over frequency domain subcarriers comprises:
A first of said three-segment structures; or
A second of said three-segment structures; or
a plurality of first three-segment structures and/or a plurality of second three-segment structures which are not arranged in sequence are freely combined.
17. A method of receiving preamble symbols according to claim 16,
Wherein, in the step of determining whether the preamble symbol is expected to be received in the baseband signal, any one or two combinations of the following preliminary position determination steps are included:
a first position preliminary judgment step: when a first time domain main signal in a plurality of time domain symbols is known information, carrying out differential operation through the first time domain main signal, carrying out differential operation on a time domain sequence corresponding to the known information, carrying out cross correlation on the time domain sequence and the time domain sequence to obtain a cross correlation value, and carrying out preliminary synchronization at least based on the obtained one or more cross correlation values;
A second position preliminary judgment step: when the time domain symbol is detected to have the three-segment structure, delay sliding self-correlation is carried out by utilizing the specific delay relation of the first three-segment structure and/or the second three-segment structure to obtain a correlation value, mathematical operation is carried out based on the correlation value, and then preliminary synchronization is carried out at least based on the mathematical operation result.
18. A method of receiving preamble symbols according to claim 16,
Wherein, if a first one of the at least one time domain subject signal adopts a pre-known frequency domain subject sequence,
Then, the integer frequency offset estimation and the initial channel estimation are performed by using the first time domain main signal.
19. a method of receiving preamble symbols according to claim 16,
Wherein, in the step of determining the position of the preamble symbol in the physical frame and decoding the signaling information carried by the preamble symbol,
And if the preamble symbol expected to be received exists, determining the position of the preamble symbol in the physical frame by using a peak value.
20. A method of receiving preamble symbols according to claim 19,
and after the position of the preamble symbol in the physical frame is determined, carrying out decimal frequency offset estimation by using the result of the peak value detection.
21. A method of receiving preamble symbols according to claim 16,
in the step of solving the signaling information carried by the preamble symbol, the method includes:
And solving the signaling information carried by the preamble symbol by using all or part of the time domain waveform of the preamble symbol and/or a frequency domain signal obtained by performing Fourier transform on all or part of the time domain waveform of the preamble symbol.
22. A method of receiving preamble symbols according to claim 21,
wherein, in the step of utilizing the frequency domain signal to solve the signaling information carried by the preamble symbol,
if the signaling sequence is modulated by the PN, the PN demodulation operation is required first, and then the sequence signaling analysis is performed.
23. A method of receiving preamble symbols according to claim 21,
Wherein, in the step of utilizing the frequency domain signal to solve the signaling information carried by the preamble symbol,
And analyzing the signaling by utilizing a signaling sequence set generated by all different root values and/or different cyclic shift values of the frequency domain main body sequence sent by the sending end.
24. a method of receiving preamble symbols according to claim 22, wherein,
If each signaling subcarrier contains more than one frequency domain body sequence and is PN modulated and frequency domain interleaved,
then the receiving end performs corresponding frequency domain de-interleaving and PN demodulation after obtaining the frequency domain effective subcarrier, and then performs the signaling analysis of the frequency domain main body sequence,
if the PN modulation is before the frequency domain interleaving, frequency domain de-interleaving is performed and then the PN is demodulated;
If the PN modulation is after the frequency domain interleaving, the PN is demodulated firstly and then the frequency domain de-interleaving is performed, or the frequency domain de-interleaving is performed firstly and then the PN is demodulated, and the demodulated PN sequence is the PN sequence of the original PN after the de-interleaving is performed.
25. a method of receiving preamble symbols according to claim 16,
After the first symbol in the time domain symbols is decoded, a plurality of subsequent symbols are demodulated, decoded and analyzed,
And after the symbol decoding of the last time domain symbol is finished, performing channel estimation again in the time domain/frequency domain by using the obtained decoding information as sending information, and performing operation with the previous channel estimation result to obtain a new channel estimation result for channel estimation of signaling analysis of the next symbol.
26. A generation device of preamble symbols, which are used for realizing time synchronization of a sending end and a receiving end in an OFDM system, is characterized by comprising:
the time domain symbol generating unit generates a frequency domain main body sequence based on one or more constant envelope zero autocorrelation sequences, generates a frequency domain subcarrier based on the frequency domain main body sequence, performs inverse Fourier transform on the frequency domain subcarrier to obtain a time domain main signal, and generates a time domain symbol with the following three-section structure based on the time domain main signal; and
A preamble symbol generating unit that generates a preamble symbol based on at least one of the time domain symbols,
Wherein a first of the three-segment structures comprises: selecting a part of generated prefixes at the tail ends of the time domain main signals and selecting a part of generated suffixes in the prefix range based on the time domain main signals;
A second one of the three-segment structures comprises: the time domain body signal, a part of the generated prefix selected at the tail end of the time domain body signal and a part of the generated prefix selected in the prefix range based on the time domain body signal,
each of the time domain symbols has:
A first of said three-segment structures; or
A second of said three-segment structures; or
A plurality of first three-segment structures and/or a plurality of second three-segment structures which are not arranged in sequence are freely combined.
27. A generation device of preamble symbols, which are used for realizing time synchronization of a sending end and a receiving end in an OFDM system, is characterized by comprising:
A body sequence generating unit, configured to generate a frequency domain body sequence, where the frequency domain body sequence is generated based on one or more constant-envelope zero auto-correlation sequences;
A frequency domain subcarrier generating unit configured to generate a frequency domain subcarrier based on the frequency domain subject sequence;
the frequency domain transformation unit is used for performing inverse Fourier transformation on the frequency domain subcarriers to obtain time domain main body signals; and
A time domain processing unit generating the preamble symbol based on at least one time domain symbol formed by the time domain body signal,
Wherein the subject sequence generating unit includes a processing generating module, the processing generating module is configured to generate the frequency domain subject sequence according to a predetermined sequence generating rule, and the predetermined sequence generating rule includes:
giving different root values to the predetermined sequence to generate; and/or
giving the same root value to a preset sequence to generate, and further performing cyclic shift on the generated sequence to generate;
The time domain symbol has the following three-segment structure:
a first of the three-segment structures comprises: selecting a part of generated prefixes at the tail ends of the time domain main signals and selecting a part of generated suffixes in the prefix range based on the time domain main signals;
a second one of the three-segment structures comprises: the time domain body signal, a part of the generated prefix selected at the tail end of the time domain body signal and a part of the generated prefix selected in the prefix range based on the time domain body signal,
wherein each of the time domain symbols transmitted over the frequency domain subcarriers comprises:
A first of said three-segment structures; or
A second of said three-segment structures; or
A plurality of first three-segment structures and/or a plurality of second three-segment structures which are not arranged in sequence are freely combined.
28. A receiving device of preamble symbol, the preamble symbol is used for realizing time synchronization of transmitting end and receiving end in OFDM system, characterized by that, it includes:
The baseband processing unit is used for processing the received physical frame to obtain a baseband signal;
A pilot symbol judging unit for judging whether the pilot symbol expected to be received exists in the baseband signal; and
the signaling analysis unit is used for determining the position of the received preamble symbol in a physical frame and solving the signaling information carried by the preamble symbol;
the preamble symbol is generated based on at least one time domain symbol formed by a time domain main signal, a frequency domain main sequence is generated based on one or more constant envelope zero autocorrelation sequences, a frequency domain subcarrier is generated based on the frequency domain main sequence, the frequency domain subcarrier is subjected to inverse Fourier transform to obtain the time domain main signal, and the time domain symbol has the following three-section structure:
A first of the three-segment structures comprises: selecting a part of generated prefixes at the tail ends of the time domain main signals and selecting a part of generated suffixes in the prefix range based on the time domain main signals;
A second one of the three-segment structures comprises: the time domain body signal, a part of the generated prefix selected at the tail end of the time domain body signal and a part of the generated prefix selected in the prefix range based on the time domain body signal,
wherein each of the time domain symbols transmitted over frequency domain subcarriers comprises:
A first of said three-segment structures; or
a second of said three-segment structures; or
A plurality of first three-segment structures and/or a plurality of second three-segment structures which are not arranged in sequence are freely combined.
Priority Applications (40)
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| CN201510061935.5A CN105991266B (en) | 2015-01-30 | 2015-01-30 | Preamble symbol generation method, reception method, generation device, and reception device |
| CN201611199976.1A CN106998312B (en) | 2014-04-16 | 2015-02-06 | Preamble symbol receiving method |
| US15/304,857 US10148476B2 (en) | 2014-04-05 | 2015-04-16 | Preamble symbol generation and receiving method, and frequency-domain symbol generation method and device |
| PCT/CN2015/076808 WO2015158292A1 (en) | 2014-04-16 | 2015-04-16 | Method for generating preamble symbol, method for receiving preamble symbol, method for generating frequency domain symbol, and apparatuses |
| KR1020197038044A KR102196222B1 (en) | 2014-04-16 | 2015-04-16 | Method for generating preamble symbol, method for receiving preamble symbol, method for generating frequency domain symbol, and apparatuses |
| KR1020197033488A KR102191859B1 (en) | 2014-04-16 | 2015-04-16 | Method for generating preamble symbol, method for receiving preamble symbol, method for generating frequency domain symbol, and apparatuses |
| KR1020167032058A KR102033742B1 (en) | 2014-04-16 | 2015-04-16 | Method and apparatus for receiving preamble symbol |
| CA3212005A CA3212005A1 (en) | 2014-04-16 | 2015-04-16 | Preamble symbol generation and receiving method, and frequency-domain symbol generation method and device |
| PCT/CN2015/076814 WO2015158295A1 (en) | 2014-04-16 | 2015-04-16 | Method and apparatus for receiving preamble symbol |
| KR1020167032057A KR101975551B1 (en) | 2014-04-16 | 2015-04-16 | Method for generating preamble symbol, method for receiving preamble symbol, method for generating frequency domain symbol, and apparatuses |
| KR1020197012400A KR102108291B1 (en) | 2014-04-16 | 2015-04-16 | Method for generating preamble symbol, method for receiving preamble symbol, method for generating frequency domain symbol, and apparatuses |
| PCT/CN2015/076812 WO2015158293A1 (en) | 2014-04-16 | 2015-04-16 | Method for generating preamble symbol, method for receiving preamble symbol, method for generating frequency domain symbol, and apparatuses |
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| US15/304,853 US10411929B2 (en) | 2014-04-05 | 2015-04-16 | Preamble symbol receiving method and device |
| US15/304,854 US10778484B2 (en) | 2014-04-16 | 2015-04-16 | Preamble symbol transmitting method and device, and preamble symbol receiving method and device |
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| KR1020167032059A KR102062221B1 (en) | 2014-04-16 | 2015-04-16 | Method for generating preamble symbol, method for receiving preamble symbol, method for generating frequency domain symbol, and apparatuses |
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| PCT/CN2015/076815 WO2015158296A1 (en) | 2014-04-16 | 2015-04-16 | Method and apparatus for receiving preamble symbol |
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| US16/172,727 US11025465B2 (en) | 2014-04-16 | 2018-10-27 | Preamble symbol receiving method and device |
| US16/726,927 US11012275B2 (en) | 2014-04-16 | 2019-12-26 | Preamble symbol transmitting method and device |
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| CA3060532C (en) | 2014-08-07 | 2022-03-15 | ONE Media, LLC | Dynamic configuration of a flexible orthogonal frequency division multiplexing phy transport data frame |
| EP3178187A1 (en) | 2014-08-07 | 2017-06-14 | Coherent Logix, Incorporated | Multi-partition radio frames |
| CA3033288C (en) | 2014-08-25 | 2021-05-04 | ONE Media, LLC | Dynamic configuration of a flexible orthogonal frequency division multiplexing phy transport data frame preamble |
| CN106789817B (en) * | 2015-02-12 | 2020-06-09 | 上海数字电视国家工程研究中心有限公司 | Preamble symbol receiving method |
| CN106789816A (en) * | 2015-02-12 | 2017-05-31 | 上海数字电视国家工程研究中心有限公司 | The method of reseptance of leading symbol |
| WO2016145070A1 (en) | 2015-03-09 | 2016-09-15 | ONE Media, LLC | System discovery and signaling |
| KR102535346B1 (en) | 2015-04-08 | 2023-05-26 | 원 미디어, 엘엘씨 | Advanced data cell resource mapping |
| US10652624B2 (en) | 2016-04-07 | 2020-05-12 | Sinclair Broadcast Group, Inc. | Next generation terrestrial broadcasting platform aligned internet and towards emerging 5G network architectures |
| CN108347399B (en) * | 2017-01-22 | 2021-05-07 | 上海矽久微电子有限公司 | Method and device for generating and receiving preamble signal |
| CN109150769B (en) * | 2017-06-13 | 2021-10-22 | 华为技术有限公司 | Method and apparatus for channel estimation |
| MX2019015327A (en) * | 2017-07-17 | 2020-02-19 | Guangdong Oppo Mobile Telecommunications Corp Ltd | Data transmission method, terminal device, and network device. |
| KR20190035391A (en) * | 2017-09-26 | 2019-04-03 | 삼성전자주식회사 | Apparatus and method for generating and detecting preamble symbol |
| CN107786480B (en) * | 2017-09-28 | 2019-10-29 | 清华大学 | Radar-communication integration signal creating method and device |
| CN108718461B (en) * | 2018-05-14 | 2020-08-11 | 电子科技大学 | Frequency offset resistant burst CPM signal frame synchronization method |
| CN110838900B (en) * | 2018-08-16 | 2021-03-09 | 上海交通大学 | Method for generating frequency domain main signal of leading symbol with variable bandwidth |
| FR3093257B1 (en) * | 2019-02-27 | 2021-03-12 | Ternwaves | ZADOFF-CHU SEQUENCE MODULATION METHOD AND DEVICE |
| CN112054982B (en) * | 2019-06-06 | 2022-05-17 | 华为技术有限公司 | Signal transmission and reception method and communication device |
| CN112449403B (en) * | 2019-09-05 | 2023-10-20 | 海能达通信股份有限公司 | Random access channel transmission method and device in low-orbit satellite communication |
| CN111988258B (en) * | 2020-09-02 | 2021-05-04 | 南京林业大学 | A random access signal set design method based on Zadoff-Chu sequence |
| CN113595955B (en) * | 2021-08-16 | 2024-01-26 | 重庆御芯微信息技术有限公司 | Elastic preamble sequence structure and time domain and frequency domain synchronization method |
| CN115766361B (en) * | 2022-10-17 | 2024-07-12 | 湖南傲英创视信息科技有限公司 | Preamble sequence processing method and related device for radar communication integrated equipment |
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| CN106998312A (en) | 2017-08-01 |
| CN106998312B (en) | 2019-12-13 |
| CN107154908B (en) | 2020-04-17 |
| CN106973026B (en) | 2020-06-09 |
| CN105991498B (en) | 2019-07-02 |
| CN106973026A (en) | 2017-07-21 |
| CN107248968B (en) | 2020-04-17 |
| CN106789813A (en) | 2017-05-31 |
| CN105991266A (en) | 2016-10-05 |
| CN107248968A (en) | 2017-10-13 |
| CN105991498A (en) | 2016-10-05 |
| CN107154908A (en) | 2017-09-12 |
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