CN106789813A - The generation method of leading symbol - Google Patents

Abstract

The invention provides a kind of generation method of leading symbol, it is characterised in that frequency domain main body sequence ZC is generated based on perseverance envelope zero auto-correlation sequence C AZAC according to predetermined sequence create-rule, and the predetermined sequence create-rule includes：The permanent envelope zero auto-correlation sequence C AZAC difference roots are assigned to generate；And/or the permanent same root generations of envelope zero auto-correlation sequence C AZAC are assigned, and the sequence of the generation further is circulated into displacement to generate, using resulting frequency domain main body sequence ZC come signaling needed for Transmission system, improve efficiency of transmission.

Description

The generation method of leading symbol

The application is the divisional application of original bill, the Application No. 201510064118.5 of original bill, and the applying date of original bill is 2015/02/06, the invention and created name of original bill is《The generation method and method of reseptance of leading symbol》.

Technical field

The invention belongs to field of broadcast communication, and in particular to the generation method and method of reseptance of a kind of leading symbol and corresponding Device.

Background technology

At present, realize that transmitting terminal and the synchronous method of destination time are substantially come real based on leading symbol in ofdm system Existing.Leading symbol is all known symbol sebolic addressing of transmitting terminal and receiving terminal of ofdm system, leading symbol mark physical frame Beginning (being named as P1 symbols), only occur in each physical frame a P1 symbol or it is continuous there are multiple P1 symbols, P1 is accorded with Number purposes include：

1) whether receiving terminal is rapidly detected with determine to transmit in channel is the signal expecting to receive；

2) basic configured transmission (such as FFT points, frame type information etc.) is provided, receiving terminal is carried out at receipt of subsequent Reason；

3) original carrier frequency deviation and timing error are detected, frequency and Timing Synchronization is reached after being used to compensate；

4) emergency alarm or broadcast system wake up.

Common, leading symbol includes physical layer formats control section (PHY Format Control, or PFC) and physics Layer content-control part (PHY Content Control, or PCC), the leading symbol of DVB_T2 systems includes P1 and P2, uses Signaling information or it is further used for transmission frame format parameter in transmission.However, prior art P1 is only capable of transmitting 7 bit signallings, Cause system transfers efficiency not enough, nor the system that can be suitably used for relevant decoding, do not consider by selecting leading character yet Number time-domain symbol number transmit required signaling with adaptive system needs.

The content of the invention

The problem that the present invention is solved is that the leading symbol transmission method of prior art causes system transfers efficiency not enough, and The system of relevant decoding can not be applied to, needed for also not considering to be transmitted by selecting the time-domain symbol number of leading symbol Signaling is needed with adaptive system.

To solve the above problems, a kind of a kind of leading symbol of the generation method of leading symbol is the embodiment of the invention provides Generation method, it is characterised in that comprise the following steps：Based on frequency domain subject sequence column-generation subcarrier in frequency domain；To frequency domain Carrier wave carries out inversefouriertransform and obtains time domain main running signal；And it is based on what the time domain main running signal was formed by least one Time-domain symbol generates the leading symbol, wherein, include the step of generate the subcarrier in frequency domain：For generating the frequency domain master The predetermined sequence create-rule of body sequence；And/or treatment is carried out to the frequency domain main body sequence for generating the frequency domain load The predetermined process rule of ripple, the predetermined sequence create-rule includes the following combination of any one or two kinds：Based on different sequences Column-generation formula is produced；And/or produced based on same sequence production, the sequence of the generation is further circulated displacement, institute Predetermined process rule is stated to include：To the pre-generatmg subcarrier obtained by being processed based on the frequency domain main body sequence according to frequency deviation value Carry out phase-modulation.

Alternatively, wherein, the step of to carrying out phase-modulation with the frequency deviation value based on the pre-generatmg subcarrier in, The subcarrier in frequency domain corresponding to the same time domain main running signal using same frequency deviation value in the subcarrier in frequency domain each Effective subcarrier carries out phase-modulation, the frequency that the subcarrier in frequency domain corresponding to the different time domain main running signals is utilized Bias is different.

Alternatively, in the predetermined sequence create-rule, the different sequence production is by assigning same Heng Bao Network zero auto-correlation sequence difference root is obtained, and the same sequence production is by assigning permanent same of envelope zero auto-correlation sequence It is worth to.

Alternatively, wherein, generate the subcarrier in frequency domain the step of include：Using in the predetermined sequence create-rule Based on different sequence productions generating the frequency domain main body sequence.

Alternatively, wherein, generate the subcarrier in frequency domain the step of include：Using in the predetermined sequence create-rule The frequency domain main body sequence is generated based on different sequence productions, continues to utilize the book office to the frequency domain main body sequence Rule is managed to generate subcarrier in frequency domain.

Alternatively, wherein, the frequency domain main body sequence is based on one or more permanent envelope zero auto-correlation sequence life Into the frequency domain main body sequence has predetermined sequence length N_ZC。

Alternatively, when being generated based on the multiple permanent envelope zero auto-correlation sequence, each has corresponding subsequence respectively Length L_M, there is sub-sequence length according to predetermined sequence create-rule generation to permanent envelope zero auto-correlation sequence each described L_MSubsequence, multiple subsequences are spliced into the predetermined sequence length N_ZCThe frequency domain main body sequence.

Alternatively, the predetermined sequence length N that the frequency domain main body sequence has_ZCNo more than described time domain main running signal has Fourier transformation length N_FFT, the step of obtain the pre-generatmg subcarrier based on the frequency domain main body series processing in include Treatment filling step, the treatment filling step includes：With reference to predetermined sequence length N_ZCThe frequency domain main body sequence is mapped to just Frequency sub-carrier and negative frequency subcarrier；With reference to the Fourier transformation length N_FFTIn the positive frequency subcarrier and described negative Fill the virtual subcarrier and direct current subcarrier of predetermined number in frequency sub-carrier outward flange；And be circulated gained subcarrier Move to left so that zero subcarrier corresponds to first position of inversefouriertransform.

Alternatively, the treatment filling step is further comprising the steps of：PN modulation is carried out for the frequency domain main body sequence, So as to carry out the mapping again, for carrying out the PN to the corresponding frequency domain main body sequence of time domain main running signal each described It is identical or differ between the PN sequences of modulation.

Alternatively, wherein, the step for by the cyclic shift is carried out in the predetermined sequence create-rule, located at carrying out Before or after the PN is modulated.

Alternatively, wherein, using the corresponding root in first time domain main running signal and/or for carrying out institute State the initial phase transmission information of the PN sequences of PN modulation.

Alternatively, wherein, when used for the subcarrier in frequency domain for carrying out signalling generated using the predetermined sequence When rule is generated,

If first time domain main running signal is using previously known in time domain main running signal described in described at least one Frequency domain main body sequence, then the frequency domain main body sequence and the corresponding frequency deviation value are not used in transmission signaling.

Alternatively, wherein, the leading symbol be located at physical frame in, by the letter that the frequency domain subject sequence biographies are defeated Order is comprising for indicating the frame format parameter of the physical frame and/or for indicating emergency broadcasted content.

Alternatively, wherein, the time-domain symbol has following three-stage structures：Wherein, the first three-stage structure is included：It is described Time domain main running signal, the neat time domain main running signal end choose the prefix of part generation and based on the time domain main body Signal chooses the suffix of part generation in the prefix ranges；Second three-stage structure is included：The time domain main running signal, Choose the prefix of part generation and based on the time domain main running signal in the prefix in the neat time domain main running signal end In the range of choose advanced the sewing of part generation, the leading symbol is included：During described with the first three-stage structure Domain symbol；Or the time-domain symbol with second three-stage structure；Or arrange in no particular order several have described first The time-domain symbol of kind of three-stage structure and/or several there is second independent assortment of the time-domain symbol of three-stage structure.

The embodiment of the present invention additionally provides a kind of generation method of leading symbol, it is characterised in that based on time domain main body letter Number generation with following three-stage structures time-domain symbol；And the leading character is generated based on time-domain symbol described at least one Number,

Wherein, the first three-stage structure is included：The time domain main running signal, the neat time domain main running signal end choose one Prefix and choose the suffix that a part is generated in the prefix ranges based on the time domain main running signal that part generates； Second three-stage structure is included：Before part generation is chosen in the time domain main running signal, the neat time domain main running signal end Sew and the advanced of part generation is chosen in the prefix ranges based on the time domain main running signal and sew, the leading character Number include：The time-domain symbol with the first three-stage structure；Or the time domain symbol with second three-stage structure Number；Or arrange in no particular order several have the first three-stage structure time-domain symbol and/or several have second Plant the independent assortment of the time-domain symbol of three-stage structure.

Alternatively, wherein, the time domain main running signal is defined as Part I, will be used as the suffix or described advanced The time domain main running signal part sewed is defined as Part II, will be defined as the 3rd as the time domain main running signal part of the prefix Part, the Part III is that a part of direct copying based on the Part I is obtained, and the Part II is based on institute A part of frequency modulation for stating Part I is obtained..

Alternatively, wherein, the length of the Part I is set to N_A, the length of the Part II is set to Len_B, will The length of the Part III is set to Len_C, the Part II starting point will be chosen in the first described three-stage structure corresponding to institute The the first sampled point sequence number for stating Part I is set to N1_1, and the Part II starting point will be chosen in three-stage structure described in second The second sampled point sequence number corresponding to the Part I is set to N1_2, meets below equation：N1_1+N1_2=2N_A-(Len_B+ Len_c), carry out the frequency modulation value f of the frequency modulation_SHThe subcarrier in frequency domain corresponding to the time-domain symbol is chosen to be spaced i.e. 1/N_AT or 1/ (Len_B+Len_c) T, and modulation first phase arbitrarily select, T is the sampling period.

Alternatively, wherein, for each the first described three-stage structure and three-stage structure, N described in each second_AValue It is 2048, if Len_CValue is 520, Len_BValue is 504, the first sampled point sequence number N1_1=1544, second sampling Point sequence number N1_2=1528, the frequency modulation value f_SHIt is 1/ (1024T) or 1/ (2048T).

Alternatively, wherein, choose the different starting points of the Part II come identifying emergent using from the Part I Broadcast.

Alternatively, wherein, the leading symbol include time-domain symbol described at least one quantity be four.

Alternatively, wherein, the three-stage structure that four time-domain symbols have respectively is sequentially：It is described the first three Segment structure, second three-stage structure, described the first three-stage structure and second three-stage structure；Or described A kind of three-stage structure, second three-stage structure, second three-stage structure and second three-stage structure；Or Second three-stage structure, described the first three-stage structure, described the first three-stage structure and the first the three sections knots Structure；Or described the first three-stage structure, second three-stage structure, described the first three-stage structure and it is described the first Three-stage structure；Or described the first three-stage structure, described the first three-stage structure, described the first three-stage structure and described Second three-stage structure；Or described the first three-stage structure, described the first three-stage structure, described the first three-stage structure with And described the first three-stage structure；Or described the first three-stage structure, described the first three-stage structure, described second three sections Structure and second three-stage structure.

Alternatively, the time domain main running signal is carried out instead by the subcarrier in frequency domain generated based on frequency domain main body sequence Fourier transformation is obtained, wherein, generate the subcarrier in frequency domain the step of include：For generating the pre- of the frequency domain main body sequence Sequencing column-generation rule；And/or treatment is carried out to the frequency domain main body sequence for generating the book office of the subcarrier in frequency domain Reason rule, the predetermined sequence create-rule includes the following combination of any one or two kinds：Produced based on different sequence productions It is raw；And/or produced based on same sequence production, the sequence of the generation is further circulated displacement, the predetermined process Rule is included：Line phase tune is entered according to frequency deviation value to the pre-generatmg subcarrier obtained by being processed based on the frequency domain main body sequence System.

The embodiment of the present invention additionally provides a kind of method of reseptance of leading symbol, it is characterised in that to the physics for receiving Frame is processed to obtain baseband signal；Judge the leading symbol received with the presence or absence of expectation in the baseband signal；It is determined that connecing Position of the leading symbol in physical frame received simultaneously solves the letter entrained by the leading symbol in the presence of signaling information Make information.

Alternatively, wherein, in judging the baseband signal with the presence or absence of expect receive the leading symbol when, can profit Carried out reliability and judged with following any one mode or any at least two modes independent assortment：Initial timing synchronization side Formula, integer frequency offset estimation mode, accurate Timing Synchronization mode, channel estimation mode and decoded result analysis mode.

Alternatively, wherein, the PRELIMINARY RESULTS as obtained by the initial timing synchronization mode carries out fractional part of frequency offset estimation.

Alternatively, wherein, when first time domain main running signal at least one time domain main running signal is not passed When defeated signaling is Given information, the initial timing synchronization mode is included：Difference fortune is carried out by first time-domain symbol Calculate, and the corresponding time domain sequences of Given information are also carried out calculus of differences, then both are carried out into cross-correlation and obtain cross correlation value, base In one or more the described cross correlation values for obtaining, initial synchronisation is at least carried out based on this result.

Alternatively, wherein, the integer frequency offset estimation is carried out based on the result obtained by the initial timing synchronization mode Mode.

Alternatively, in the step of carrying out integer frequency offset estimation, including any one or two kinds in following two modes Combination：First integer frequency offset estimation mode is included：Use sweep method to all or part of time domain waveform for intercepting out with After different frequency deviations are modulated, several frequency sweep time-domain signals are obtained, Fourier inversion institute will be carried out by known frequency domain sequence Known time-domain signal and frequency sweep time-domain signal each described enter line slip it is related after, by the frequency sweep of maximum correlation peaks The frequency deviation value that time-domain signal is modulated as integer frequency offset estimation value；And/or second integer frequency offset estimation mode include：Will The position result interception main body time-domain signal according to initial timing synchronization carries out the subcarrier in frequency domain obtained by Fourier transformation Displacement is circulated by different shift values in swept frequency range, the receiving sequence corresponding to effective subcarrier is intercepted, to the reception Sequence and known frequency domain sequence carry out predetermined operation and carry out inversefouriertransform again, are become based on some groups of anti-Fourier of shift value The corresponding relation that result is obtained between the shift value and the integer frequency offset estimation value is changed, integer frequency offset is derived from and is estimated Evaluation.

Alternatively, after completing the integer frequency offset estimation, solved after being compensated to frequency deviation and then to transmission signaling Analysis.

Alternatively, after completing the integer frequency offset estimation, first at least one time domain main running signal When the time domain main running signal does not transmit signaling for Given information, the accurate Timing Synchronization side is carried out using the known signal Formula.

Alternatively, the channel estimation mode, is contained in the step of being parsed to transmission signaling, including：When upper one After the time domain main running signal decoding terminates, by the use of resulting decoding information as the information of transmission, enter again in time domain/frequency domain Row channel estimation, and certain certain operations is carried out with channel estimation results before, new channel estimation results are obtained, under being used for One channel estimation of the signaling resolution of time domain main running signal.

The embodiment of the present invention also each provides the life with the leading symbol corresponding to above-mentioned generation method and method of reseptance Into device.

Compared with prior art, technical solution of the present invention has the advantages that：

The generation method and method of reseptance of the leading symbol for providing according to embodiments of the present invention, the generation dress of leading symbol Put and reception device, because multiple three-stage structures of leading symbol any one or independent assortment are produced, each three sections of symbol Main part can transmit signaling in spatial structure and frequency-domain structure respectively, in time domain, can be realized using three-stage structure Coherent demodulation, at the same further through suffix or it is advanced sew implementation frequency modulation to solve the problems, such as mono-tone interference, further through two kinds Different three-stage structures solves the problems, such as the small inclined estimation failure under dangerous delays；In addition on frequency domain, by based on different Sequence production and/or based on same sequence production produce further by the sequence of the generation be circulated displacement generation frequency domain Subcarrier, optionally carries out phase-modulation further combined with to the pre-generatmg subcarrier obtained by treatment according to frequency deviation value, with Improve system transfers efficiency.Further, the time domain main running signal in first time-domain symbol can use known symbol, for making It is the initial synchronisation and channel estimation of relevant detection, while time-domain symbol in leading symbol can be needed neatly to select according to system Number transmit required signaling.

Brief description of the drawings

Fig. 1 is the schematic flow sheet of the embodiment one of the generation method of leading symbol of the invention；

Fig. 2 is the spatial structure schematic diagram of physical frame in embodiments of the invention；

Fig. 3 is the Physical Frame Structure signal comprising form control section and content-control part in embodiments of the invention Figure；

Fig. 4 be embodiments of the invention leading symbol in frequency domain schematic diagram corresponding to a time-domain symbol；

Fig. 5 is the schematic diagram of the first three-stage structure in embodiments of the invention；

Fig. 6 is second schematic diagram of three-stage structure in embodiments of the invention；

Fig. 7 is the schematic flow sheet of the embodiment two of the generation method of leading symbol of the invention；

Fig. 8 is the schematic flow sheet of the embodiment of the method for reseptance of leading symbol of the invention；

Fig. 9 is the logics for obtaining preliminary Timing Synchronization result in the present invention using 44 groups of accumulated correlation values of time-domain symbol Computing block diagram；And

Figure 10 is to obtain patrolling for preliminary Timing Synchronization result using 2 the 2 of time-domain symbol groups of accumulated correlation values in the present invention Collect computing block diagram.

Specific embodiment

Leading symbol has efficiency of transmission not high during inventor has found prior art, and not enough, initial timing is same for transmission flexibility ratio Step performance is bad, it is impossible to implement relevant decoding so that decoding performance not good such problem under low signal-to-noise ratio.

Regarding to the issue above, inventor is by research, there is provided a kind of generation of leading symbol and method of reseptance, this is leading The design of symbol not only improves the Timing Synchronization performance of leading symbol, while the characteristics of using Cyclic Prefix, it is possible to implement phase Dry decoding, improves the problem of receptivity in most cases.Meanwhile, time domain and frequency domain all transmit signaling, and frequency domain leads to Cross various methods and implement signalling, and time domain can implement urgent broadcast mark.Meanwhile, by neatly using time-domain symbol Number come realize need transmission signaling, with applicable system need, realize transmission flexibility and scalability.Meanwhile, pin To the generation method of leading symbol of the invention, corresponding receiving algorithm is specifically described, these receiving algorithms can be with relatively low Ground complexity realizes the performance of very robust.

In order that the above objects, features and advantages of the present invention can become apparent it is understandable, below in conjunction with the accompanying drawings to this hair Bright specific embodiment is described in detail.

Fig. 1 is the schematic flow sheet of the embodiment of the generation method of leading symbol of the invention.As shown in figure 1, this implementation The generation method of leading symbol, comprises the following steps in example：

Step S1-1：Based on frequency domain subject sequence column-generation subcarrier in frequency domain；

Step S1-2：Inversefouriertransform is carried out to subcarrier in frequency domain and obtains time domain main running signal；And

Step S1-3：Leading symbol is generated based on the time-domain symbol that time domain main running signal is formed by least one.

Wherein, the step of generating subcarrier in frequency domain includes：(1) rule are generated for generating the predetermined sequence of frequency domain main body sequence Then；And/or (2) carry out treatment to frequency domain main body sequence for generating the predetermined process rule of subcarrier in frequency domain,

(1) predetermined sequence create-rule includes the following combination of any one or two kinds：

(1a) is based on different sequence productions and produces；And/or

(1b) is produced based on same sequence production, and the sequence of the generation further is circulated into displacement,

(2) predetermined process rule is included：To the pre-generatmg subcarrier obtained by being processed based on frequency domain main body sequence according to Frequency deviation value carries out phase-modulation.

Fig. 2 is the spatial structure schematic diagram of physical frame in embodiments of the invention.

As shown in Fig. 2 this implementation discloses a kind of frame structure, two physical frames, each physical frame point are just shown in Fig. 2 Not Bao Han leading symbol and data area, wherein, leading symbol be located at data area before.

Data area is used for transmitting data information, such as TS bags or IP bags etc..

Whether it is the signal expecting to receive that leading symbol is used to rapidly detecting with determine to transmit in channel, there is provided basic Configured transmission (such as FFT points, frame type information etc.), makes receiving terminal to carry out receipt of subsequent treatment；Detect original carrier Frequency deviation and timing error, reach frequency and Timing Synchronization after being used to compensate；Urgent broadcast wake-up etc..

Fig. 3 is the Physical Frame Structure signal comprising form control section and content-control part in embodiments of the invention Figure.

As shown in figure 3, Physical Frame Structure includes leading symbol and data area, wherein leading symbol is included：By physical layer Form control section PFC and physical layer content-control part PCC.Certainly, leading symbol involved in the present invention is not limited to Comprising PFC parts and PCC parts.

Form control section PFC is made up of (oblique wire frame representation is used in figure) one or more time-domain symbols, during each OFDM Domain symbol size is identical.In the present embodiment, time-domain symbol uses OFDM symbol.

Fig. 5 is the schematic diagram of the first three-stage structure in embodiments of the invention；It is in embodiments of the invention with Fig. 6 Two kinds of schematic diagrames of three-stage structure.

At least one time-domain symbol is included in the form control section PFC of leading symbol, due to time domain symbol in the present embodiment Following the first three-stage structure or second three-stage structure number are used, thus, the time-domain symbol that leading symbol is included also may be used Referred to as three-stage structure time-domain symbol.But be not limited, meeting the time-domain symbol in above-mentioned leading symbol can also adopt With the other structures of not three-stage structure.

By Fig. 5 and Fig. 6, in the present embodiment one, time-domain symbol has following three-stage structure：Such as first in Fig. 5 Plant three-stage structure：Prefix (C sections), Yi Jiji that time domain main running signal (A sections), the rear portion based on the time domain main running signal are generated The suffix (B sections) of part generation is chosen in prefix ranges in time domain main running signal；Such as second three-stage structure in Fig. 6： Prefix (C sections) that time domain main running signal (A sections), the rear portion based on the time domain main running signal are generated and based on time domain main body Signal is chosen the advanced of part generation in prefix ranges and is sewed (B sections).

By one section of time domain main running signal (being indicated using A in figure), used as Part I, the least significant end of neat Part I is according to pre- The fixed rule that obtains takes out a part, and predetermined process is simultaneously copied to the front portion of the Part I and (marked with C in figure generating Part III Show) so that as prefix, meanwhile, a part is taken out according to the predetermined rule that obtains from the rear portion of Part I, predetermined process is carried out Process and copy to the rear portion of the Part I or process and copy to the front portion of prefix and generate Part II (with B in figure Sign) so as to mutually should be used as suffix respectively or sew in advance so that, generate respectively B as shown in Figure 5 as suffix the first three Segment structure (CAB structures) and B are used as second three-stage structure (BCA structures) as shown in Figure 6 sewed in advance.

From the point of view of the time-domain symbol with three-stage structure, the leading symbol generated in the present embodiment can be included：Tool There is the time-domain symbol of the first three-stage structure；Or with second time-domain symbol of three-stage structure；If or in no particular order arranging Doing a time-domain symbol with the first three-stage structure and/or several has second freedom of the time-domain symbol of three-stage structure Combination.That is leading symbol can only include CAB or BCA, or several CAB or several BCA, or quantity is not limited Any independent assortment for arranging in no particular order of several CAB and several BCA.It should be strongly noted that before of the invention Lead symbol but be not limited to the only structure comprising C-A-B or B-C-A, also can also include other spatial structures, such as tradition CP knots Structure etc..

A sections is obtained for example, by 2048 points of IFFT conversion based on certain section of frequency domain main body sequence, by the C in three-stage structure Section is the direct copying of a part in A sections, and B sections is the modulated signal section of a part in A sections, and the data area of B is no more than C's Data area, that is, select the scope to the part A of modulated signal section B without departing from the model intercepted as the part A of prefix C Enclose.Preferably, the length sum of the length of B and C is the length of A.

If N_AIt is the length of A, if Len_CIt is the length of C, Len_BIt is the length of modulated signal section B.If the sampled point sequence number of A It is 0,1 ... N_A- 1. set the sampled point that N1 is copied to the corresponding Part I A of starting point of modulated signal section Part II B as selection Sequence number, N2 is the sampled point sequence number of the corresponding Part I A of terminal that selection is copied to modulated signal section Part II B.Wherein,

N2=N1+Len_B- 1 (formula 1)

Generally, that Part II B sections is implemented is modulated to frequency modulation, modulation M sequence or other sequences etc., in this implementation By taking frequency modulation as an example, if P1_A (t) is the time-domain expression of A, then the time-domain expression of the first common leading symbol is

Wherein, frequency modulation value f_SHThe corresponding i.e. 1/N in subcarrier in frequency domain interval of time-domain OFDM symbol can be chosen for_AT, or 1/(Len_B+Len_c) T wherein T be the sampling period, N_AIt is the length of time-domain OFDM symbol, such as, N_AIt is 1024, takes f_SH=1/ 1024T, and frequency modulation can arbitrarily select first phase.In order that correlation peak is sharp, f_SHIt is 1/ (Len that can also select_BT) or Close to the numerical value of its value.

In the structure of B-C-A, frequency modulation value is just with C-A-B structures conversely, and modulation can arbitrarily select first phase.

The first sampling that Part II (B) starting point corresponds to Part I (A) will be chosen in the first three-stage structure (CAB) Point sequence number is set to N1_1, and Part I (A) is corresponded to by Part II (B) starting point is chosen in second three-stage structure (BCA) Second sampled point sequence number is set to N1_2, the first sampled point sequence number N1_1 and the second sampled point sequence number N1_2 to be needed to meet below equation

N1_1+N1_2=2N_A-(Len_B+Len_c) (formula 4)

Meeting the benefit of such relation is, the delay relation of C sections to B sections of identical content is tied with B-C-A in C-A-B structures The delay relation of B sections to A sections identical content is identical in structure, in C-A-B structures the delay relation of A sections to B sections of identical content with The delay relation of B sections to C sections identical content is identical in B-C-A structures, is realized beneficial to receiver.And C-A-B structures and B-C-A knots In structure, if the modulation to B sections of use is frequency modulation, two kinds of frequency deviation value f of structure_SHContrast is wanted, beneficial to reception Machine is realized.

The symbol of C-A-B structures is represented with sequence number 1, the symbol of B-C-A structures is represented with sequence number 2.It is A1 then to set P1_A (t) Time-domain expression, P2_A (t) is the time-domain expression of A2, then the time-domain expression of C-A-B three-stage structures is

The time-domain expression of B-C-A three-stage structures is

Wherein, the first three-stage structure and second three-stage structure for arranging in no particular order, the difference according to priority can divide Do not form different by several the first three-stage structures and/or several second leading character of three-stage structure independent assortment Number.It is sequentially 1 time-domain expression of first leading symbol of C-A-B and 1 B-C-A that citing below is given, and is sequentially 1 The time-domain expression of second leading symbol of individual B-C-A and 1 C-A-B.

So, the time-domain expression of the first leading symbol is：

The time-domain expression of the second leading symbol is：

The time-domain expression of the first leading symbol and the second leading symbol can infer other C-A-B and B-C-A groups according to this Close and formed, it is no longer repeated herein.

In as above-mentioned situation, when C-A-B structures and B-C-A structures are cascaded, small inclined estimation under dangerous delays can be solved The problem of failure.When dangerous delays cause C sections and A sections to offset, first the CB of structure sections and second BC sections of structure still So can be used to Timing Synchronization and estimate small partially.

The quantity that leading symbol includes at least one time-domain symbol is set to transmit four symbols, is given below several More preferably four time-domain symbol structures, be sequentially arranged in following several structures any one：

(1) C-A-B, B-C-A, C-A-B, B-C-A；Or

(2) C-A-B, B-C-A, B-C-A, B-C-A；Or

(3) B-C-A, C-A-B, C-A-B, C-A-B；Or

(4) C-A-B, B-C-A, C-A-B, C-A-B；Or

(5) C-A-B, C-A-B, C-A-B, B-C-A；Or

(6) C-A-B, C-A-B, C-A-B, C-A-B or

(7) C-A-B, C-A-B, B-C-A, B-C-A.

Wherein, the structure of such four time-domain symbols of such as (1) C-A-B, B-C-A, C-A-B, B-C-A, the effect of cascade Fruit plays maximum.The structure of such four time-domain symbols of such as (2) C-A-B, B-C-A, B-C-A, B-C-A, by successive character A portions The protection interval divided is elongated, and usual first symbol is known signal, therefore uses C-A-B.

Include a preferred embodiment of three-stage structure, N_AIt is 2048, if Len_CIt is 520, Len_B=504, N1_1= 1544, N1_2=1528, make the expression formula that P1_A (t) is time domain main body A, then can derive the time domain table of C-A-B and B-C-A It is up to formula

And

Further, f_SHMay be selected to be 1/ (1024T) or 1/ (2048T).

Further, the different starting points that Part II B is chosen from Part I A can be utilized to be broadcasted come identifying emergent, i.e., By choosing different N1, or N1_1 and N1_2, by being copied to B sections of starting point come identifying emergent broadcast system.Such as C- The symbol of the three-stage structure of A-B, N1_1=1544 mark conventional systems, and N1_1=1528 identifying emergent broadcast systems.Compare again Such as, the symbol of the three-stage structure of B-C-A, N1_2=1528 mark conventional systems, and N1_2=1544 identifying emergent broadcast systems.

Understand that time domain main running signal A is by based on frequency domain main body sequence with reference to the generation step of the above-mentioned leading symbol of Fig. 1 Generation subcarrier in frequency domain carries out inversefouriertransform IFFT and obtains.Formed with C-A-B or B-C-A by time domain main running signal A again The time-domain symbol of such three-stage structure, so that the leading symbol with least one time-domain symbol in forming the present embodiment.

Explanation is described to the generating process in the time domain main running signal A of three-stage structure (CAB or BCA) below.

Fig. 4 be embodiments of the invention leading symbol in frequency domain schematic diagram corresponding to a time-domain symbol.

As shown in figure 4, a subcarrier in frequency domain generation for time-domain symbol in the PFC of leading symbol is given, based on frequency domain Main body sequence obtains the subcarrier in frequency domain.

In the generation of subcarrier in frequency domain, comprising for generate frequency domain main body sequence predetermined sequence create-rule and/or Treatment is carried out to frequency domain main body sequence for generating the predetermined process rule of subcarrier in frequency domain.

For predetermined sequence create-rule, the generating process of frequency domain main body sequence is more flexible, predetermined sequence life The following combination of any one or two kinds is included into rule：Produced based on different sequence productions；And/or based on the life of same sequence An accepted way of doing sth is produced, and the sequence of the generation further is circulated into displacement.In the present embodiment, using permanent envelope zero auto-correlation sequence (CAZAC sequences) is realized, that is to say, that above-mentioned different sequence production is by assigning same CAZAC sequences difference root Obtain, or, above-mentioned same sequence production is obtained by assigning the same root of CAZAC sequences.

Frequency domain main body sequence is generated based on one or more CAZAC sequence, and frequency domain main body sequence has predetermined sequence long Degree N_ZC.Predetermined sequence length N_ZCThe Fourier transformation length N that no more than time domain main running signal has_FFT。

Treatment filling step is carried out to frequency domain main body sequence, is included on the whole：With reference to predetermined sequence length N_ZCBy frequency domain Main body sequence is mapped to positive frequency subcarrier and negative frequency subcarrier；With reference to Fourier transformation length N_FFTIn positive frequency subcarrier With the virtual subcarrier and direct current subcarrier that predetermined number is filled in negative frequency subcarrier outward flange；And carry out gained subcarrier Ring shift left so that zero subcarrier corresponds to first position of inversefouriertransform.

Here, enumerating based on an example for CAZAC sequences generation.Firstly generate N_ZCThe frequency domain main body sequence of length (Zadoff-Chu, sequence, ZC), is one kind of CAZAC sequences,

If sequence formula is：

Note N_ZCN can be equal to or less than_root, you can it is complete by the complete Zadoff-Chu sequence of a certain root or cut Short generation, then may be selected to one PN sequence of same length of this ZC sequence modulation, obtain ZC_M sequences, by ZC_M sequences point Into two parts, left-half length isNegative frequency part is mapped to, right half part length isIt is mapped to just Frequency-portions, N_ZCA certain natural number may be selected, no more than A sections of FFT length；Additionally, at the edge of negative frequency, fillingThe zero of number, and at the edge of positive frequency, fillThe zero of number, is virtual subcarrier； Therefore, the particular sequence be byIndividual zero,The ZC sequences of individual PN modulation, 1 direct current subcarrier,The ZC sequences of individual PN modulation andIndividual zero order is constituted；Effective number of sub carrier wave is N_ZC+1。

The specifically generating process of frequency domain main body sequence, such as sequence formulaIf can choose Dry difference root q, for the sequence that each root q is generated, can carry out different cyclic shifts and obtain more multisequencing again again, By this 2 kinds of modes it is one of any or two transmit signaling

Such as, 256 root q are taken, 256 sequences are obtained, you can 8 bit of transmission, based on 2^8=256, and shift value It is set as 1024, then each sequence in 256 can carry out the displacement of 0-1023, i.e. each sequence by 1024 kinds of displacements again The signalling of 10 bits is realized again, based on 2^10=1024, thus can transmit 8+10=18 bit signallings altogether.

, to bit field, the signaling transmitted can be comprising the frame format parameter for indicating physical frame for these protocol mappings And/or for indicating emergency broadcasted content, wherein, frame format parameter is such as：Frame number, frame length, the bandwidth of PCC symbols, data The bandwidth in region, the FFT sizes and protection interval length of PCC symbols, PCC modulation and coding parameter.

Cyclic shift in above-mentioned predetermined sequence create-rule can be placed on before carrying out PN sequence modulations to ZC sequences and carry out, Can also be placed on after PN sequence modulations is carried out, in addition, being used for the frequency domain master corresponding to time domain main running signal each described Body sequence is carried out identical between the PN sequences of the PN modulation or differed.

Wherein, if first time domain main running signal uses previously known frequency domain main body at least one time domain main running signal Sequence, then the frequency domain main body sequence and corresponding frequency deviation value are not used in transmission signaling, and PFC in follow-up time-domain symbol is transmitted Signaling.

Frequency domain main body sequence (ZC sequences) used by last OFDM symbol and the frequency domain used by first OFDM symbol The phase difference 180 degree of main body sequence (ZC sequences), this is used to refer to last OFDM symbol of PFC；First in PFC The root sequence of the ZC sequences that OFDM symbol is used, generally certain length without cyclic shift, and under the length, ZC sequences have one Individual set, therefore the present invention, from a certain sequence in this set, this can indicate a certain information, such as version number or indicated number According to the type of service or pattern transmitted in frame；Additionally, using the corresponding root and/or use in first time domain main running signal In the initial phase transmission information of the PN sequences for carrying out PN modulation, the initial phase of PN also has certain signalling capability, for example, refers to Show version number.

Here, enumerating the example based on the generation of multiple CAZAC sequences.Each CAZAC sequence has corresponding subsequence respectively Length L_M, there is sub-sequence length L according to the generation of above-mentioned predetermined sequence create-rule to each CAZAC sequence_MSubsequence, will Multiple subsequences are spliced into predetermined sequence length N_ZCFrequency domain main body sequence.

Specifically, in the generation of the effective subcarrier of frequency domain, it is made up of M CAZAC sequence, if M CAZAC sequence Length is respectively L₁,L₂,...L_M, and meetThe generation method of each CAZAC sequence and above-mentioned identical, only increases Plus a step, after M CAZAC sequence is generated, it is N to be spliced into length_ZCSequence, may be selected after PN sequence modulations formed ZC_M, then after carrying out frequency-domain-interleaving, form new ZC_I, then fill out and be placed on above-mentioned identical sub-carrier positions, left-half length ForNegative frequency part is mapped to, right half part length isIt is mapped to positive frequency part, N_ZCMay be selected a certain Natural number, no more than A sections of FFT length；Additionally, at the edge of negative frequency, fillingThe zero of number, and in positive frequency The edge of rate, fillsThe zero of number, is virtual subcarrier；Therefore, the particular sequence be byIndividual zero,The ZC sequences of individual PN modulation, 1 direct current subcarrier,The ZC sequences of individual PN modulation WithIndividual zero order is constituted, wherein, can also be placed on after frequency-domain-interleaving the step for modulation PN is carried out.

Sub-carrier positions filling can also take other treatment filling steps, not limit here.

To be circulated by above-mentioned treatment filling gained subcarrier and moved to left, after carrying out the later half frequency spectrum exchange of first half, be similar to Fftshift in Matlab, i.e., correspond to zero subcarrier first position of discrete inversefouriertransform, is made a reservation for Length N_FFTFrequency-domain OFDM symbol pre-generatmg subcarrier.

Further, in this subcarrier in frequency domain implemented generating process, except preferably using above-mentioned predetermined sequence Create-rule, can also preferably be used in process frequency domain main body sequence and be advised with generating the predetermined process of subcarrier in frequency domain Then.The present invention does not limit using any one or two in predetermined process rule and predetermined sequence create-rule to form frequency domain Subcarrier.

Predetermined process rule is included：Phase-modulation is carried out according to frequency deviation value S to pre-generatmg subcarrier, wherein, the pre-generatmg Subcarrier is carried out the steps such as treatment filling, ring shift left and is obtained by above-mentioned to frequency domain main body sequence.In the predetermined process In rule, subcarrier in frequency domain corresponding to same time domain main running signal A using same frequency deviation value S in the subcarrier in frequency domain each Effective subcarrier carries out phase-modulation, the frequency deviation value difference S that the subcarrier in frequency domain corresponding to different time domain main running signal A is utilized.

For predetermined process rule specifically, such as the subcarrier expression formula of former OFDM symbol is

a₀(k) k=0,1,2 ... N_FFT- 1,

(formula 12)

It is then as follows to the expression formula that each subcarrier carries out phase-modulation by a certain frequency deviation value such as s：

Wherein, the operation that zero carrier is multiplied need not actually be carried out, and only effective subcarrier need to be operated.Frequency deviation value s can The scope of selection is [- (N_FFT-1),+(N_FFT- 1) integer], the Fourier that frequency deviation value s is based on time domain main running signal and has becomes Change length N_FFTIt is determined that, its different value can be used for transmitting signaling.

It should be noted that above-mentioned also may be used by frequency deviation value S to the implementation method that each pre-generatmg subcarrier carries out phase-modulation Realized in time domain.It is equivalent to：The frequency-domain OFDM symbol of original unmodulated phase is obtained into time domain ODFM symbols through IFFT conversion, Time domain main running signal A is generated after time-domain OFDM symbol being circulated into displacement, letter is transmitted by different cyclic shift values Order.In the present invention, in a frequency domain each effective subcarrier is carried out phase-modulation to be described by a certain frequency deviation value, it shows And the time domain equivalent operating method being clear to is also within the present invention.

In sum, the present embodiment can be entered in the generating process of subcarrier in frequency domain based on frequency domain main body sequence selection It is any one in the above-mentioned predetermined sequence create-rule (1a) of row and predetermined sequence create-rule (1b) and predetermined process regular (2) It is individual or at least two independent assortment.

For example, signaling is transmitted using the generation method of the leading symbol of regular (1a).

Such as go up root q described by example and take 256 kinds, the cyclic shift value of each root q takes 0-1023, then can transmit 8+10 =18 bit signallings.

For another example, for example, transmit signaling with the generation method of regular (1a) and the leading symbol of regular (2).

Root q takes 2 kinds, and time-domain OFDM symbol length is 2048, takes 1024 kinds of shift values, with 2 to be spaced, such as 0,2,4, 6 ... .2046 etc., transmit 1+10=11 bit signallings.

For another example, for example, only with the generation method of the leading symbol of regular (2).

Root q is fixed, and phase-modulation is carried out by different frequency deviation value S to subcarrier in frequency domain, than such as above-mentioned N_FFTIt is 2048,S values 0,8,16 ... 2032 etc., be equivalent to not phase modulated Frequency-domain OFDM symbol carries out the time-domain OFDM symbol after IFFT, carries out 256 kinds of cyclic shifts of different shift values, is interval with 8, Such as 0,8,16 ... 2032 etc., transmit 8 bit signallings.Here, the present invention does not limit moving to left or moving to right for cyclic shift, works as s During for positive number, correspondence time domain cyclic is moved to left, such as value is 8, and 8 are moved to left corresponding to time domain cyclic；When s is negative, when to corresponding to Domain ring shift right, such as value are -8, and 8 are moved to right corresponding to time domain cyclic.

It is of the invention to additionally provide a kind of method of reseptance of leading symbol embodiment two.Fig. 7 is leading symbol of the invention Generation method embodiment two schematic flow sheet.

As shown in fig. 7, in the present embodiment leading symbol generation method, comprise the following steps：

Step S2-1：Based on time domain main running signal time-domain symbol of the generation with following three-stage structures；And

Step S2-2：Leading symbol is generated based at least one time-domain symbol.

Wherein, the first three-stage structure in three-stage structure is included：The time domain main running signal, the neat time domain main body letter Number end choose the prefix of part generation and choose a part in the prefix ranges based on the time domain main running signal The suffix of generation；Second three-stage structure in three-stage structure is included：The time domain main running signal, the neat time domain main running signal Choose the prefix of part generation and choose part life in the prefix ranges based on the time domain main running signal in end Into it is advanced sew,

Leading symbol is included：The time-domain symbol with the first three-stage structure；Or with described second three The time-domain symbol of segment structure；Or arrange in no particular order several have the first three-stage structure time-domain symbol and/or Several have second independent assortment of the time-domain symbol of three-stage structure.

The present embodiment two have with implement one in corresponding technology essential factor for example the first three-stage structure, second three The specific configuration of segment structure, omits identical explanation herein.

Embodiments of the invention additionally provide a kind of method of reseptance of leading symbol.Fig. 8 is leading symbol of the invention The schematic flow sheet of the embodiment of method of reseptance.

As shown in figure 8, the method for reseptance of the leading symbol in the present embodiment, comprises the following steps：

Step S3-1：Physical frame to receiving is processed to obtain baseband signal；

Step S3-2：Judge the leading character that method is generated is generated as described above with the presence or absence of expectation reception in baseband signal Number；

Step S3-3：Determine position in physical frame of received leading symbol and solve entrained by the leading symbol Signaling information.

During step S3-2 judges the baseband signal with the presence or absence of expect receive the leading symbol when, using with Lower any one mode or any at least two modes independent assortment carry out reliability judgement：It is initial timing synchronization mode, whole Several times offset estimation mode, accurate Timing Synchronization mode, channel estimation mode and decoded result analysis mode.

Step S3-2 includes initial timing synchronization mode, for primarily determining that position of the leading symbol in physical frame. Further, after initial synchronisation, the result that can be also based on initial timing synchronization carries out small inclined estimation.In addition, further, initially After synchronization, being also based on the result obtained by the initial timing synchronization mode carries out the integer frequency offset estimation mode.

When the leading symbol generation method of transmitting terminal is used, first time domain main running signal is not transmitted into signaling is known letter During breath, (1.) initial timing synchronization mode should include：Calculus of differences is carried out by first time-domain symbol, and by Given information pair The time domain sequences answered are also carried out calculus of differences, then both are carried out into cross-correlation obtain cross correlation value, based on for obtaining or many Individual cross correlation value, at least carries out initial synchronisation based on this result.

Next the integer frequency offset estimation mode based on initial timing synchronization result is illustrated, is carrying out integral multiple In the step of offset estimation, including the combination of any one or two kinds in following two modes：.

First integer frequency offset estimation mode is included：Using sweep method to all or part of time domain waveform for intercepting out After being modulated with different frequency deviations, several frequency sweep time-domain signals are obtained, Fourier inversion will be carried out by known frequency domain sequence The known time-domain signal of gained and each frequency sweep time-domain signal enter line slip it is related after, the frequency sweep time domain of maximum correlation peaks is believed Number frequency deviation value modulated as integer frequency offset estimation value；And/or

Second integer frequency offset estimation mode is included：Main body time domain letter will be intercepted according to the position result of initial timing synchronization Number carry out the subcarrier in frequency domain obtained by Fourier transformation and be circulated displacement by different shift values in swept frequency range, interception is effective Receiving sequence corresponding to subcarrier, carry out predetermined operation to the receiving sequence and known frequency domain sequence carries out anti-Fourier's change again Change, the inversefouriertransform result based on some groups of shift values obtains the correspondence pass between shift value and integer frequency offset estimation value System, is derived from integer frequency offset estimation value.

Citing below specifically describes whole inclined estimation mode, can be carried out using first Given information of symbol of PFC whole inclined Estimate and initial channel estimation, it is necessary to for first Given information of symbol.

First integer frequency offset estimation mode, the position that the leading symbol detected according to initial timing synchronization occurs, cuts The all or part of the time domain waveform of the leading symbol for receiving is taken, by the way of frequency sweep, i.e., is become with fixed frequency Change step footpath, such as correspond to integer frequency offset interval, after the part time domain waveform is modulated into upper different frequency deviation, when obtaining several Domain signal

Wherein, T is sampling period, f_sIt is sample frequency.And known frequency domain sequence is laggard by pre- subcarrier filling mode The corresponding time-domain signal of row inverse fourier transform is A2, using A2 as known signal and each A1_yEnter line slip related, select That A1 of existing maximum correlation peaks_y, then the frequency deviation value y for being modulated to it as integer frequency offset estimation values.

Wherein, the frequency deviation region of confrontation required for swept frequency range correspondence system, than the frequency deviation if desired for the positive and negative 500K of confrontation, And systematic sampling rate is 9.14M, leading symbol main body is 2K length, then swept frequency range isI.e. [- 114, 114]。

Second integer frequency offset estimation mode：The position that the leading symbol detected according to initial timing synchronization occurs, cuts Main body time-domain signal A is taken, and carries out FFT, the circulation that the subcarrier in frequency domain after FFT is carried out the different shift values of swept frequency range is moved Position, then intercepts and receiving sequence is obtained corresponding to effective subcarrier, certain computing is carried out with receiving sequence and known frequency domain sequence (logical Often it is conjugate multiplication, or is divided by), its result is carried out into IFFT, the result to IFFT carries out certain operations, such as take maximum diameter Energy, or take some big footpath energy accumulations.So several shift values, by after IFFT several times, one being obtained every time Operation result, then can obtain some groups of operation result.Judge which shift value has corresponded to integer based on this some groups of results Times offset estimation, thus obtains integer frequency offset estimation value.

Common determination methods are that maximum corresponding shift values of group of selection energy based on some groups of result, as Integer frequency offset estimation value.

The specific algorithm of integer frequency offset estimation has many kinds, repeats no more.

In addition, using known frequency domain sequence in comprising Given information first symbol for receiving and first symbol And/or it carries out the corresponding time-domain signal of inverse fourier transform and completes channel estimation, can equally select to be carried out in time domain and/or Carried out in frequency domain, including can be not reinflated here with time-frequency combination computing.

Further, after completing above-mentioned integer frequency offset estimation, carried out after being compensated to frequency deviation and then to transmission signaling Parsing.

Further selectively, after completing integer frequency offset estimation, first at least one time domain main running signal When time domain main running signal does not transmit signaling for Given information, accurate Timing Synchronization mode is carried out using the known signal.

Comprising channel estimation mode in the step of being parsed to transmission signaling, the channel estimation mode includes：When upper After one time domain main running signal decoding terminates, by the use of resulting decoding information as the information of transmission, enter again in time domain/frequency domain Row channel estimation, and certain certain operations is carried out with channel estimation results before, new channel estimation results are obtained, under being used for One channel estimation of the signaling resolution of time domain main running signal.

Further, after frame format parameter and/or urgent broadcast content is solved, according to content of parameter and can have determined that The position of PFC symbols is obtained the position of PCC symbols or the position of data symbol and PCC symbols is subsequently parsed based on this Or data symbol.

More in particular, for as in embodiment two with unlimited any combination CAB or BCA from For the leading symbol of the three-stage structure being defined in time domain angle：

For in the receiving terminal for receiving above-mentioned such leading symbol, (2.) initial timing synchronization mode to include：Work as detection When having three-stage structure to time-domain symbol, peculiar using each CAB and/or BCA is dealt with relationship and/or modulation relation is prolonged Auto-correlation is slided late to obtain one or more groups of cumulative correlations, then carries out specific mathematical based on one or more groups of correlations After computing, preliminary Timing Synchronization is at least carried out based on operation result value.

For continuing with such leading symbol, the difference that Part II is chosen in transmitting terminal utilizes Part I rises During point mark urgent broadcast, initial timing synchronization is parsed urgent wide by following any one or any two kinds of phase independent assortments Broadcast：The different delays relation of identical content between Part III and Part II；And phase between Part I and Part II With the different delays relation of content, urgent broadcast and common broadcast are sent to distinguish.

Further, when the PFC in sending leading symbol is simultaneously comprising following two situations (a) with (b),

A first time domain main running signal in () described at least one time domain main running signal is not used in transmission signaling Given information；

(b) and detect the time domain main running signal there is the three-stage structure,

By any one in above-mentioned (1.) initial timing synchronization mode and (2.) initial timing synchronization mode or Two kinds are combined to complete initial timing synchronization.Wherein when being completed based on two kinds, then by (1.) initial timing synchronization mode institute The the second preliminary synchronisation operation values obtained by the first preliminary synchronisation operation values and (2.) initial timing synchronization mode for obtaining are carried out again Ranking operation, initial timing synchronization is completed based on the ranking operation value.

Illustrate to primarily determine that leading symbol position in physical frame with reference to specific method data and operational formula Method.

[(1.) initial timing synchronization mode]

Wherein, when first symbol of PFC does not transmit signaling, when being known signal, (1.) initial timing synchronization mode can Calculus of differences is carried out by first symbol of PFC, the corresponding time-domain signal of Given information calculus of differences is also carried out, then incite somebody to action both Cross-correlation is carried out, initial synchronisation is carried out based on the related result of one or more groups of difference, primarily determine that leading symbol in physical frame Position.

The detailed process of difference correlation in (1.) initial timing synchronization mode is described below, and single group difference phase is introduced first The process of pass.

Determine difference value, will receive base band data is carried out by the calculus of differences of difference value, by the sheet corresponding to Given information Ground time domain sequences are also carried out, by the calculus of differences of difference value, the result of the two calculus of differences then being carried out into cross-correlation again, obtain To the difference correlated results corresponding to the difference value.The calculating process of the difference correlated results of this single group is prior art.If poor Score value is D, and reception base band data is r_n, each specific formula of step is described as follows；

First, will receive base band data is carried out by the calculus of differences of difference value

By after calculus of differences, the phase place that carrier wave frequency deviation brings becomes fixed carrier phase e^j2πDΔf, Δ here F represents carrier frequency offset.

Local time domain sequences are also carried out calculus of differences simultaneously

Then the reception data and local difference sequence after difference are carried out into cross-correlation, is obtained

There is no multipath in system, also in the case of no noise,

Relevant peaks can be well given, and peak value does not receive carrier wave deviation effects.Frame synchronization/timing synchronization position profit Obtained with such as following formula

Knowable to above-mentioned single group difference related operation process, difference related algorithm can resist the shadow of arbitrarily large carrier wave frequency deviation Ring, but due to receiving sequence first is carried out into calculus of differences so that signal noise strengthens, and under low signal-to-noise ratio, noise increases It is strong very serious, cause signal to noise ratio significantly to deteriorate.

In order to avoid above mentioned problem, therefore more than single group difference related operation, multigroup difference correlation can be implemented, such as N's Value is 64, implements 64 groups of difference correlations, is obtainedWherein D (0), D (1) ..., D (N-1) are choosing The N number of different difference value selected.

Specific mathematical computing is carried out to N number of result, final correlated results is obtained.

In the present embodiment, for the process that multigroup difference correlation (64 groups) is chosen make according to predetermined difference selected rule, Can be based on the performance requirement of Transmission system using in following two any one：

(1) first predetermined difference selected rule：Difference value D (i) arbitrarily selects N number of different value and meets D (i) ＜ L, wherein L is the length of the corresponding local time domain sequences of Given information.

(2) second predetermined difference selected rules：Difference value D (i) selects N number of different value for arithmetic progression and meets D (i) ＜ L, i.e.,K is satisfactionNormal integer, wherein L is the corresponding local time domain sequences of Given information Length.

Predetermined process computing is carried out to this N number of result (64), final correlated results is obtained, predetermined process computing here Preferred embodiment have two kinds, be illustrated respectively.

The first predetermined process computing：

Difference value D (i) can arbitrarily select N number of different value, meet D (i) ＜ L.Because, the optional difference value D of institute (i), the phase e after every group of difference correlation^j2πD(i)ΔfI=0 ..., N-1 are different, it is impossible to direct vector addition, so being only capable of Enough weighted absolute values are added or average.Predetermined process computing is carried out to N number of different difference correlated results by below equation, is obtained To final difference result.Following formula is that absolute value is added the example for obtaining final difference result.

Second predetermined process computing：

Difference value D (i) can arbitrarily select N number of different value, meet D (i) ＜ L, and meet D (i) for arithmetic progression, i.e. D (i+1)-D (i)=K, K are satisfactionNormal integer.

By this rule selection difference value, obtain asDifference correlation after, then will be adjacent 2 groups of difference correlations carry out conjugate multiplication, the value after below equation obtains N-1 group conjugate multiplications.

Because, by this conjugate multiplication by originally every group of different phase e^j2πD(i)ΔfBecome identical e^j2πKΔf, institute With the N-1 groups RM obtained by equation 8 below_i,mVector addition can be weighted or final difference result is averagely obtained, with To than the first predetermined process computing better performance.Following formula obtains the example of final difference result for vector addition.

It should be noted that in the case of being using the above-mentioned second predetermined difference selected rule when difference value D (i), not only may be used Acquisition conjugate multiplication value is weighted vector addition or average to obtain most last phase again during second predetermined process computing is stated in matching Result is closed, can also be matched according to directly exhausted by weighting at least two difference correlated results in above-mentioned first predetermined process computing Value is added or average to obtain final correlated results.

So as to be based on computing R_dc,mPrimarily determine that leading symbol in the position of physical frame.

[(2.) initial timing synchronization mode]

Wherein, it is peculiar using C-A-B and/or B-C-A when leading symbol has the spatial structure of C-A-B or B-C-A Deal with relationship and/or modulation relation, baseband signal is carried out necessary inverse processing and/or signal demodulation after carry out delay slip Auto-correlation obtains 1 group or multigroup accumulated correlation values, then based on one or more groups of accumulated correlation values postpone relationship match and/ Or after specific mathematical operation, operation values are used for initial timing synchronization, primarily determine that leading symbol in the position of physical frame.Lift For example, postpone slip auto-correlation acquisition accumulated correlation values formula as follows：

U₁(n)=r (n) r^*(n-N_A)

May be selected to U₁' (n) carry out energy normalized and obtain U_1s'(n)。

I.e.

Energy normalized can also take other method, U₁Conjugate operation * is taken in (n), can also be realized by r (n), and r (n- N_A) conjugation is not taken.

In the structure of each C-A-B or B-C-A, can respectively obtain the CA based on identical content, AB and CB tri- and add up Correlation.

For example, here only with C-A-B structure examples, B-C-A can be pushed away accordingly.

Enter line slip delay to A sections of identical part using C sections related, can add the step of note above-mentioned energy normalized On, repeat no more here.The structure of every 1 C-A-B or B-C-A can obtain three correlations：U_ca' (n), U_cb' (n), U_cb'(n)

Enter line slip using the B sections of part for only modulating frequency deviation identical with C sections and postpone correlation：

Enter line slip using the B sections of part for only modulating frequency deviation identical with A sections and postpone correlation：

Wherein, the desirable 1/f of corr_len_SHT, to avoid continuous wave CO_2 laser, or takes Len_BTo cause peak value sharp.

And when leading symbol includes multiple three-stage structures, can obtain tri- accumulated correlation values of multigroup CA, AB and CB, i.e., it is many Group U_ca' (n), U_cb' (n), U_ab' (n), based on a group in many class values and it is multigroup carry out postpone relationship match and/or mathematics fortune Calculate, obtain last operation values, the operation values are used for initial synchronisation.

Such as, for for preferred 4 time-domain symbols with three-stage structure, it is arranged as C-A-B, B-C-A, C-A- When B, B-C-A, obtain

Then can be byIn one or more carry out postpone relationship match and/ Or be added again after phase adjustment or averagely, obtain last U_ca(n).Because they have identical phase value. Delay matching is exemplified below：

And

Can be byIn one or more carry out postpone relationship match and/or It is added again after phase adjustment or averagely, is obtained last U_cb-ab(n).Because they have identical phase value. Delay matching is exemplified below：

And

Can be byIn one or more carry out postpone relationship match and/or It is added again after phase adjustment or averagely, is obtained last U_ab-cb(n).Delay matching is exemplified below：

And

Finally, based on U_ca(n) and U_cb-ab(n) and U_ab-cbN one or more of () carry out delay matching and carry out specific again Computing, delay matching here is exemplified below：

U_ca(n), U_cb-ab(n),U_ab-cb(n-A)

Initial timing synchronization is completed based on operation result, optional network specific digit computing can be that absolute value is added.Such as take maximum Value position completes initial timing synchronization.

It should be noted that in view of the influence of systematic sampling clock deviation, in the above-described embodiments, can be by some of them Postpone the due number that postpones of correlator and add and subtract one, formation postpones numbers with three after plus-minus one in itself, according to these three delay numbers Implement to slide and postpone auto-correlation, reselection correlated results it is the most obvious that, while it is estimated that timing offset.

Fig. 9 obtains preliminary Timing Synchronization result in just giving this implementation using 44 groups of accumulated correlation values of time-domain symbol Logical operation block diagram；And Figure 10 just gives in this implementation and obtains preliminary using 22 groups of accumulated correlation values of time-domain symbols The logical operation block diagram of Timing Synchronization result.

Be not in general manner, if when in leading symbol except with C-A-B or B-C-A structure, also comprising other time domains During characteristic, except the time synchronization method of the design feature using above-mentioned C-A-B or B-C-A, then it is superimposed with for other time domains Other time synchronization methods that design feature is implemented, without departing from spirit described in the invention.

Further, after preliminary completion initial timing synchronization, determined using (1.) mode and/or the preliminary of (2.) mode When synchronized result can also carry out fractional part of frequency offset estimation.

For the algorithm that fractional part of frequency offset is estimated, for concrete example, when Timing Synchronization mode preliminary using (1.),Its maximum is taken, corresponding phase is e^j2πKΔf, Δ f can be calculated and be converted into Corresponding 1st small bias.

Again for concrete example, when (2.) preliminary Timing Synchronization mode, U is taken_caThe angle of maximum in (n), finally Go out the 2nd small bias, then by U_cb-ab(n) and U_ab-cbAfter (n) conjugate multiplication, the corresponding angle of maximum is also taken, the 3rd can be calculated small Bias.As above the angle in logical operation block diagram is used to seek small inclined schematical sections, can be based on the 2nd small bias, the 3rd small bias One of any sum it two carry out small inclined estimation.

Needed for the PFC in sending leading symbol is implemented comprising (1.) and (2.) preliminary Timing Synchronization mode simultaneously During feature, based on the 1st, the 2nd, one of any or any two combination at least of the 3rd small bias obtain small inclined estimate.

In the signaling information step solved entrained by the leading symbol of above-mentioned steps S3-3, signaling information parsing step Suddenly include：All or part of time domain waveform using leading symbol and/or all or part of time domain waveform by the leading symbol By frequency-region signal resulting after Fourier transformation, the signaling information entrained by the leading symbol is solved.

Such as, by PFC parts, each receives the length N of the corresponding A fragment positions of symbol_FFTTime domain receive data carry out phase After answering the FFT computings of length, zero carrier is removed, the subcarrier in frequency domain for receiving is taken out according to effective sub-carrier positions, using it To carry out signaling resolution.

If sending sequence to be modulated by PN, the subcarrier in frequency domain of reception first can be first demodulated PN operations by receiving terminal, ZC sequence signaling resolutions are carried out again.Also signaling resolution can directly directly be carried out with the subcarrier in frequency domain of the reception for not demodulating PN.This The two to differ only in the method that known array set takes different, will hereafter illustrate.

Further, in signaling information step is parsed, can using all of frequency domain main body sequence transmitted by transmitting terminal Can different roots and/or different frequency domain shift value and the known signaling sequence set that produces and all possible frequency domain modulation Frequency deviation value parses signaling.Here known array set, comprising following meanings：

It is all possible take root in and/or all possible frequency-domain circular displacement produce CAZAC sequences, if in transmitting terminal PN is modulated, then known array set can both refer to the arrangement set after modulation PN, can also refer to the arrangement set before modulation PN.If Receiving terminal has carried out demodulation PN operations in frequency domain, then known array collection uses the arrangement set before modulation PN, if receiving terminal exists Frequency domain does not use demodulation PN, then known array collection is using the arrangement set after modulation PN.To use known array set correspondence Time domain waveform, then the arrangement set after certain PN using CAZAC sequence modulations.

Further, if after transmitting terminal generation CAZAC sequences, also having carried out the operation that interweaves, then known array set both may be used Through the arrangement set after frequency-domain-interleaving after finger CAZAC sequences/and/or modulation PN, can also refer to through the arrangement set before frequency-domain-interleaving. If receiving terminal has carried out deinterleaving operation in frequency domain, known array collection uses the arrangement set before frequency-domain-interleaving, if connect Receiving end does not use deinterleaving to operate in frequency domain, then known array collection is using the arrangement set after frequency-domain-interleaving.It is known to use The corresponding time domain waveform of arrangement set, then necessarily use CAZAC sequences and/or modulation PN and the sequence sets for being deinterleaved Close, i.e. the set of each last sequence composition being mapped on subcarrier.

The two kinds of transmission situations for being used from the generation method of following transmitting terminal respectively are come the detailed process to signaling resolution Do as described below.

<First sends situation>When in the generating process of subcarrier in frequency domain, using based on different sequence production generations And/or based on same sequence production produce the sequence of the generation is further circulated displacement when.

Frequency domain signaling sub-carriers and channel estimation value and all possible frequency domain main body sequence are carried out into certain number student movement Calculation carries out signaling resolution, wherein, specific mathematical computing comprising it is following any one：

(1) the maximum likelihood related operation of channel estimation is combined；Or

(2) after channel estimation value being carried out into channel equalization to frequency domain signaling sub-carriers, then with all possible frequency domain main body Sequence carries out related operation, selects maximum related value as the decoding result of signaling resolution.

The process of signaling resolution in the case of the first transmission is detailed below.

For example, if i=0:M-1, M are signaling sub-carriers number, j=0:2^P- 1, P make bit number for frequency domain is transmitted, i.e., Correspondence signaling sub-carriers collection has 2^PIndividual element and each element correspondence length for M sequence .H_iIt is each signaling sub-carriers pair The channel estimation value answered, SC_rec_iIt is the frequency domain signaling sub-carriers value for receiving,For signaling sub-carriers concentrate j-th element In i-th value.

Then

Take max (corr_j) corresponding to j, that is, obtain frequency-domain transmission signaling.

If transmitting terminal has modulated PN, SC_rec_iDemodulated without PN, thenCorrespondence is using the sequence sets after modulation PN Close；If SC_rec_iDemodulated by PN, thenCorrespondence is using the arrangement set before modulation PN.

For operation of the transmitting terminal comprising frequency-domain-interleaving, can simply push away, it is no longer special here to illustrate.Alternatively, frequency domain The decoding process for transmitting signaling can also be carried out in time domain, corresponding after being converted through IFFT using known signaling sub-carriers collection Time domain signaling waveform collection directly synchronizes related to the time-domain received signal for obtaining multipath accurate location, takes correlation absolute value That maximum, it is also possible to solve frequency-domain transmission signaling, repeat no more here.

If the signaling sub-carriers of PFC each symbol are by more than one ZC sequence modulations PN and carry out frequency-domain-interleaving and constitute, After receiving terminal obtains the effective subcarrier of frequency domain, carry out corresponding frequency domain and deinterleave operation, demodulation PN operations, then carry out ZC sequence signalings Parsing.If PN is before frequency-domain-interleaving for modulation, advanced line frequency domain deinterleaves, then is demodulated PN.If modulation PN is handed in frequency domain After knitting, then PN is first demodulated, then carry out frequency domain deinterleaving, or advanced line frequency domain deinterleaves, then it is demodulated PN.But now solve The PN sequences of tune are the PN sequences after original PN is deinterleaved.

<Second sends situation>When being used to pre-generatmg subcarrier with the frequency in the generating process of the subcarrier in frequency domain When bias carries out phase-modulation.

Signaling resolution is carried out using any one in following three kinds parsing signaling methods or at least two are combined：

First parsing signaling method：Frequency-region signal is taken out after effective subcarrier carries out channel equalization, and known signaling collection Each known array carry out matching/division arithmetic, directly ask for frequency domain frequency deviation value or carry out anti-Fourier's computing；And/or

Second parsing signaling method：When it is determined that the frequency domain signaling collection only one of which known array of each time-domain symbol and front and rear When the known array of symbol is also identical, only by the related time domain cyclic shift value for being solved of delay between front and rear time-domain symbol come Carry out parsing signaling；And/or

3rd parsing signaling method：To before the time-domain received signal of each time-domain symbol and all possible frequency modulation Time domain known array corresponding to known frequency domain sequence carries out accordingly cross-correlation, and predetermined process is carried out to cross correlation value, then Further by predetermined process after the cross correlation value of front and rear symbol carried out according to the predetermined symbol length relation of the time-domain symbol The delay of front and rear mark space length is related, solves time domain cyclic shift values, is parsed based on the time domain cyclic shift values and transmitted Signaling.

Specifically, in the signaling information step entrained by the leading symbol is solved using frequency-region signal, if originator frequency Domain sequence generation carries out phase-modulation gained to each effective subcarrier by above-mentioned frequency deviation value S, then enforceable parsing is received and calculated Method has following 3 kinds：

1st parsing receiving algorithm：

Frequency-region signal is taken out the value of effective subcarrier, after carrying out channel equalization, each subcarrier is believed with known frequency domain The corresponding subcarrier of each frequency domain known array for making collection match/division arithmetic after, IFFT computings are carried out, based on IFFT's Result solves transmitted signaling (comprising frequency domain main body sequence and time domain cyclic shift values are transmitted makes).

The such as known not phase modulated preceding expression formula of subcarrier in frequency domain that sends is A_k, phase modulated rear expression formula is

After channel, the frequency domain data expression formula for receiving is

Wherein A_kFor known signaling concentrates k-th given value of carrier wave.So, carry out

Or E_k=R_k·(A_k·H_k)^*Or

Wherein σ²It is to estimate noise variance, then by E_kIFFT computings are carried out, the position of the maximum absolute value of operation result is used In parsing signaling, i.e. frequency domain modulation frequency deviation value S (time domain cyclic shift values).

For example, it is known that frequency domain signaling collection only has 1 known array, that is, only rely on frequency domain modulation frequency deviation value S (time domain is followed Ring shift value) transmission signaling, then based on a result of IFFT, the position that its maximum absolute value value occurs parses time domain cyclic The signaling of shift transport.

For example, it is known that frequency domain signaling collection there are 2 known arrays, produced simultaneously by the CAZAC sequences of different root root Modulated through PN, transmit 1 signaling, while also depending on domain frequency modulation value (time domain cyclic shift values) transmits 8 signalings, then distinguished 2 above-mentioned treatment are obtained into 2 results of IFFT, based on 2 results of IFFT, big that of selection maximum absolute value value is solved Frequency domain passes 1 bit signalling, while parsing 8 bits of time-domain cyclic shift transmission according to the position that big peak value occurs Signaling.

2nd parsing receiving algorithm：

The signaling that time domain cyclic shift values are transmitted, i.e. frequency domain modulation are solved frequently based on front and rear intersymbol delay correlation Bias.This method can be used for the corresponding known frequency domain signaling collection of each time domain main running signal and there was only a known array, and front and rear The corresponding known array of time domain main running signal of time-domain symbol is identical, only relies on frequency domain modulation frequency deviation value (time domain cyclic shift values) Transmission signaling.

Specifically, such as time domain shift transport N-bit signaling, corresponds respectively to 2^NIndividual shift value, so by this 2^NIt is individual Shift value adds 2 intersymbol inherent delay numbers respectively, obtains 2^NIndividual length of delay, receiver attempts 2^NThe delay of individual length of delay D Correlation, postpones associated expression as above

Wherein, L can be chosen for the length of time domain main body A, n₀After for timing just synchronous or accurate Timing Synchronization, characterize The starting point of time domain main body A.

It is obtained 2^NIndividual E (D), takes out corresponding that D of maximum, you can be back-calculated to obtain the signaling of transmission.

3rd parsing receiving algorithm：

Based on time-domain received signal, all possible frequency modulation corresponding with the time domain main running signal of each time-domain symbol Time domain known array corresponding to preceding known frequency domain sequence collection carries out cross-correlation, and specific operation is carried out based on cross correlation value, then Cross correlation value after treatment is further carried out front and rear 2 mark space length as the 2nd parsing receiving algorithm delay Correlation solves the signaling that time domain cyclic shift values are transmitted.

Here the specific operation for being carried out to cross correlation value, is as a rule to extract big footpath and filter noise.Specifically, It is exactly to retain the larger peak fractions of cross correlation value, and bottom is made an uproar and partly set to 0.It is follow-up further based on the cross correlation value after treatment The delay for carrying out front and rear 2 symbols is related, and its method and judgement are same with the 2nd parsing receiving algorithm, repeat no more here.

For being explained further, if the corresponding known frequency domain sequence collection institute of the time domain main running signal of each time-domain symbol is right The time domain known array more than one answered, i.e. transmitting terminal both comprising using frequency domain generation cazac sequences different root values and/or Signaling is transmitted using the cyclic shift of the frequency domain generation same root of CAZAC sequences, it is effective to each also to press frequency deviation value by frequency domain When subcarrier carries out the method transmission signaling of phase-modulation, then multiple time domain known arrays are carried out mutually with time-domain received signal Correlation, then each time-domain symbol select maximum that of cross correlation value and carry out subsequent treatment, using maximum that of cross-correlation Element in individual its corresponding known frequency domain sequence collection, you can parse different root values by frequency domain generation CAZAC sequences with/ Or the signaling transmitted using the cyclic shift of the frequency domain generation same root of CAZAC sequences.Further, using follow-up mutual simultaneously The delay that correlation further carries out front and rear 2 mark space length is related effective to each by frequency deviation value by frequency domain to solve Subcarrier carries out the signaling that the method for phase-modulation is transmitted.

Further, no matter using which kind of signaling resolution mode, when the upper time domain main running signal decoding of PFC terminates Afterwards, it is assumed that decoding is correct, by the use of Last decoding information as the information of transmission, channel is carried out again in time domain/frequency domain and is estimated Meter, and certain certain operations is carried out with previous channel estimation results, new channel estimation results are obtained, for next time domain The channel estimation of the signaling resolution of main running signal.

Further, after signaling resolution completes to solve frame format parameter and/or urgent broadcast content, can be according to parameter Content and have determined that the position of PFC symbols come after obtaining the position of PCC symbols or the position of data symbol and being carried out based on this Continuous parsing PCC symbols or data symbol.

Finally illustrate, in receiving terminal, judge whether to expect that the leading symbol for receiving there can be various methods, Such as judged by the operation result after the correlation in above-mentioned the 1. initial timing synchronization, can also be estimated by follow-up integer frequency offset Meter, accurate Timing Synchronization, the reliability of channel estimation or decoded result judges.

Wherein, judged by the operation result after the correlation in above-mentioned the 1. initial timing synchronization, can be using fixed threshold Method, i.e. operation result exceed fixed threshold, then it is assumed that there is the leading symbol part for expecting to receive, and based on the operation result Corresponding position can release the position that corresponding three-stage structure time-domain symbol occurs.

Not shown in figure, embodiments of the invention additionally provide a kind of generating means of leading symbol, the generating means Including：Subcarrier generation unit, based on frequency domain subject sequence column-generation subcarrier in frequency domain；Frequency-domain transform unit, to subcarrier in frequency domain Carry out inversefouriertransform and obtain time domain main running signal；And Time Domain Processing unit, it is based on time domain main running signal by least one The time-domain symbol generation leading symbol of formation.

Wherein, subcarrier generation unit is included：Sequence for generating the predetermined sequence create-rule of frequency domain main body sequence Generation module；And/or treatment is carried out to frequency domain main body sequence at the carrier wave of predetermined process rule for generating subcarrier in frequency domain Reason module.

Predetermined sequence create-rule includes the following combination of any one or two kinds in sequence generating module：Based on different sequences Column-generation formula is produced；And/or produced based on same sequence production, the sequence of the generation is further circulated displacement, carry Predetermined process rule is included in ripple processing module：To the pre-generatmg subcarrier obtained by being processed based on frequency domain main body sequence according to Frequency deviation value carries out phase-modulation.

Not shown in figure, embodiments of the invention additionally provide a kind of generating means of leading symbol, the generating means Including：Time domain generation unit, based on time domain main running signal time-domain symbol of the generation with following three-stage structures；And leading generation Unit, leading symbol is generated based at least one time-domain symbol.

Wherein, the first three-stage structure is included：Time domain main running signal, neat time domain main running signal end choose part generation Prefix and the suffix of part generation is chosen in prefix ranges based on time domain main running signal；Second three-stage structure bag Contain：Time domain main running signal, neat time domain main running signal end are chosen the prefix of part generation and are existed based on time domain main running signal The advanced of part generation is chosen in prefix ranges to sew.

The leading symbol generated by leading generation unit is included：Time-domain symbol with the first three-stage structure；Or tool There is second time-domain symbol of three-stage structure；Or several time-domain symbols with the first three-stage structure for arranging in no particular order And/or several have second independent assortment of the time-domain symbol of three-stage structure.

Not shown in figure, embodiments of the invention additionally provide a kind of reception device of leading symbol, the reception device Including：Baseband processing unit, the physical frame to receiving is processed to obtain baseband signal；Judging unit, judges that base band is believed With the presence or absence of the leading symbol for expecting to receive in number；Signaling resolution unit, it is determined that the leading symbol for receiving is in physical frame Position simultaneously solves the signaling information entrained by the leading symbol in the presence of signaling information.

The generating means and reception device of the leading symbol provided in this implementation and leading symbol in above-described embodiment Generation method, method of reseptance distinguish corresponding, then the structure and technology essential factor having in device can be by generation method phases Should change to be formed, repeat no more in this description will be omitted.

Although the present invention is disclosed as above with preferred embodiment, it is not for limiting the present invention, any this area Technical staff without departing from the spirit and scope of the present invention, may be by the methods and techniques content of the disclosure above to this hair Bright technical scheme makes possible variation and modification, therefore, every content without departing from technical solution of the present invention, according to the present invention Any simple modification, equivalent variation and modification for being made to above example of technical spirit, belong to technical solution of the present invention Protection domain.

Claims (10)

1. a kind of generation method of leading symbol, it is characterised in that comprise the following steps：

Based on frequency domain subject sequence column-generation subcarrier in frequency domain；

Inversefouriertransform is carried out to the subcarrier in frequency domain and obtains time domain main running signal；And

The leading symbol is generated based on the time-domain symbol that the time domain main running signal is formed by least one,

Wherein, the step of generating the subcarrier in frequency domain includes：Predetermined sequence for generating the frequency domain main body sequence is generated Rule；And/or treatment is carried out to the frequency domain main body sequence for generating the predetermined process rule of the subcarrier in frequency domain.

2. the generation method of leading symbol as claimed in claim 1, it is characterised in that

Wherein, the predetermined sequence create-rule includes the following combination of any one or two kinds：

Produced based on different sequence productions；And/or

Produced based on same sequence production, the sequence of the generation is further circulated displacement.

3. the generation method of leading symbol as claimed in claim 1, it is characterised in that

Wherein, the predetermined process rule is included：Pre-generatmg obtained by being processed based on the frequency domain main body sequence is carried Ripple carries out phase-modulation according to frequency deviation value.

4. the generation method of leading symbol as claimed in claim 1, it is characterised in that

Wherein, in the step of to carrying out phase-modulation with the frequency deviation value based on the pre-generatmg subcarrier,

The subcarrier in frequency domain corresponding to the same time domain main running signal is using same frequency deviation value in the subcarrier in frequency domain Each effective subcarrier carries out phase-modulation,

The frequency deviation value that the subcarrier in frequency domain corresponding to the different time domain main running signals is utilized is different.

5. the generation method of leading symbol as claimed in claim 1, it is characterised in that

In the predetermined sequence create-rule,

The different sequence production is obtained by assigning same permanent envelope zero auto-correlation sequence difference root,

The same sequence production is obtained by assigning the permanent envelope same root of zero auto-correlation sequence.

6. the generation method of leading symbol as claimed in claim 5, it is characterised in that：

Wherein, the frequency domain main body sequence is based on one or more permanent envelope zero auto-correlation sequence generation,

The frequency domain main body sequence has predetermined sequence length N_ZC。

7. the generation method of leading symbol as claimed in claim 5, it is characterised in that：

When being generated based on the multiple permanent envelope zero auto-correlation sequence, each has corresponding sub-sequence length L respectively_M,

There is sub-sequence length L according to predetermined sequence create-rule generation to permanent envelope zero auto-correlation sequence each described_M's Subsequence,

Multiple subsequences are spliced into the predetermined sequence length N_ZCThe frequency domain main body sequence.

8. the generation method of leading symbol as claimed in claim 7, it is characterised in that：

The predetermined sequence length N that the frequency domain main body sequence has_ZCThe Fourier that no more than described time domain main running signal has becomes Change length N_FFT,

Comprising treatment filling step in the step of obtaining the pre-generatmg subcarrier based on the frequency domain main body series processing, at this Reason filling step includes：

With reference to predetermined sequence length N_ZCThe frequency domain main body sequence is mapped to positive frequency subcarrier and negative frequency subcarrier；

With reference to the Fourier transformation length N_FFTIt is pre- in the positive frequency subcarrier and negative frequency subcarrier outward flange filling Determine the virtual subcarrier and direct current subcarrier of number；And

Gained subcarrier is circulated and is moved to left so that zero subcarrier corresponds to first position of inversefouriertransform.

9. the generation method of leading symbol as claimed in claim 8, it is characterised in that：

The treatment filling step is further comprising the steps of：

PN modulation is carried out for the frequency domain main body sequence, so that the mapping is carried out again,

For the corresponding frequency domain main body sequence of time domain main running signal each described is carried out the PN modulation PN sequences it Between it is identical or differ.

10. the generation method of leading symbol as claimed in claim 9, it is characterised in that

Wherein, by the cyclic shift is carried out in the predetermined sequence create-rule the step for, located at carrying out the PN modulation Before or after.