CN105991500A - Method and device for receiving preambles - Google Patents

Abstract

The invention provides a method and a device for receiving a preamble, which can be applied to when a transmitting end meets a preset transmitting rule. The method is characterized by comprising steps: whether a preamble exists in a processed baseband signal is judged; the position of the preamble in a physical frame is determined and carried signaling information is analyzed, wherein the step of determination and analysis comprises a sub step in which a time domain main body signal for each time domain symbol is subjected to Fourier transform and effective sub carriers are then extracted; each effective sub carrier and a known sub carrier corresponding to each frequency domain known sequence in a known frequency domain signaling set for the time domain symbol are subjected to predetermined mathematical operation and then inverse Fourier transform, and an inverse Fourier result is obtained corresponding to each frequency domain known sequence; and based on an inverse Fourier selection result selected from one or more inverse Fourier results in a first predetermined selection rule for each time domain symbol, and by using predetermined processing operation between multiple time domain symbols, the signaling information is analyzed based on the obtained inter-symbol processing result.

Description

Method and device for receiving preamble symbol

Technical Field

The invention belongs to the field of broadcast communication, and particularly relates to a method and a corresponding device for receiving a preamble symbol.

Background

At present, a method for implementing time synchronization between a transmitting end and a receiving end in an OFDM system is basically implemented based on preamble symbols. The preamble symbol is a symbol sequence known to both the transmitting end and the receiving end of the OFDM system, the preamble symbol marks the beginning of a physical frame (named as P1 symbol), only one P1 symbol or a plurality of P1 symbols occur consecutively in each physical frame, and the uses of the P1 symbol include:

1) enabling a receiving end to quickly detect whether a signal transmitted in a channel is an expected received signal;

2) providing basic transmission parameters (such as FFT point number, frame type information and the like) to enable a receiving end to carry out subsequent receiving processing;

3) detecting initial carrier frequency deviation and timing error for achieving frequency and timing synchronization after compensation;

4) emergency alerts or broadcast system wake-up.

Generally, a method for sending preamble symbols in a sending end, for the purpose of improving system transmission efficiency, there is a technical consideration that different sequences are generated based on different sequence generating formulas or a same sequence generating formula is used to perform cyclic shift in a time domain or modulation frequency offset in a frequency domain to generate a time domain main signal, and then the time domain main signal is further processed to generate a time domain symbol, the time domain symbol with the structure is used to transmit signaling, and for this reason, on a receiving end side, after a time domain symbol expected to be received exists in a preliminary interpretation positioning, the signaling is analyzed by directly differentiating a front symbol frequency domain and a rear symbol frequency domain, however, the method for analyzing in the receiving end has the following disadvantages: the robustness is not high under the conditions of multipath channels and low signal-to-noise ratio; when the channel estimation is not accurate or interference paths occur due to various reasons, misjudgment is easy to occur.

Disclosure of Invention

The invention solves the problem that the method and the device for receiving the preamble symbol in the prior art have low robustness under the conditions of multipath channel and low signal-to-noise ratio on the premise that the effective subcarrier carries out cyclic shift in a time domain or modulates frequency offset in a frequency domain to generate a time domain symbol to transmit a signaling, and the signaling is analyzed by utilizing direct difference of the frequency domains of the front symbol and the rear symbol after the time domain symbol expected to be received is initially interpreted and positioned; the problem of misjudgment is easy to occur when the channel estimation is not accurate or the interference path occurs due to various reasons.

In order to solve the above problem, an embodiment of the present invention provides a method for receiving a preamble symbol, which is applicable when a sending end meets a predetermined sending rule, and is characterized by including the following steps: judging whether a preamble symbol exists in the baseband signal obtained by processing; determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol, wherein the step of determining and analyzing comprises: carrying out Fourier transform on the time domain main signal of each time domain symbol and extracting effective subcarriers; performing inverse Fourier transform on each effective subcarrier and a known subcarrier corresponding to each frequency domain known sequence in a known frequency domain signaling set of the time domain symbol after predetermined mathematical operation, and obtaining an inverse Fourier result corresponding to each frequency domain known sequence; and each time domain symbol is based on a selected inverse Fourier result selected from one or more inverse Fourier results by a first preset selection rule, then a plurality of time domain symbols are subjected to preset processing operation, and the signaling information is solved based on the obtained inter-symbol processing result.

Optionally, wherein the predetermined sending rule: and after the frequency domain main body sequence corresponding to the time domain main body signal in each sent time domain symbol is processed to obtain a generated pre-generated subcarrier, performing phase modulation or inverse Fourier transform on each effective subcarrier in a frequency domain by using a preset frequency offset value S, and performing cyclic shift in the time domain.

Optionally, the method further comprises selecting the selected inverse fourier result according to a first predetermined selection rule by taking an absolute value or taking the square of the absolute value of the selected inverse fourier result.

Optionally, wherein the first predetermined selected rule comprises selecting at peak maximum and/or selecting at peak-to-average ratio maximum.

Optionally, the method further comprises a noise filtering processing step, wherein the noise filtering processing step comprises: the inverse Fourier result of each time domain symbol can be subjected to noise filtering, a large value is reserved, and small values are all set to zero.

Optionally, the parsed signaling information includes: different frequency domain sequences transmit signaling and/or signaling transmitted by frequency domain modulation frequency offset, namely time domain cyclic shift value.

Optionally, the known frequency domain signaling set refers to all possible sequences of the subject time domain signal corresponding to each time domain symbol that are padded to the frequency domain sequence of subcarriers before the modulation phase of the frequency domain subcarrier.

Optionally, when the known frequency domain sequence set of the time domain symbols has only 1 known sequence, the first predetermined selection rule is to directly take the unique inverse fourier result of each time domain symbol thereof as the inverse fourier selection result, perform predetermined processing operation between a plurality of time domain symbols, and solve the signaling information based on the obtained inter-symbol processing result.

Optionally, wherein the predetermined mathematical operation comprises: conjugate multiplication or division.

Optionally, wherein the step of performing a predetermined processing operation between the plurality of time domain symbols and solving the signaling information based on the obtained inter-symbol processing result includes: and circularly shifting the next time domain symbol, multiplying or conjugatively multiplying the next time domain symbol by the previous time domain symbol, accumulating to obtain an accumulated value, finding out a shift value corresponding to the maximum accumulated value in all the preset frequency offset values or the cyclic shift values, and calculating the signaling information by using the shift value.

The embodiment of the present invention further provides a preamble symbol receiving apparatus, which is suitable for a transmitting apparatus to satisfy a predetermined transmission rule, and is characterized in that the apparatus includes: a processing judgment part for judging whether the baseband signal obtained by the processing has the preamble symbol; and a positioning analysis part for determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol, wherein the positioning analysis part comprises: the carrier extraction unit is used for extracting effective subcarriers after carrying out Fourier transform on the time domain main body signal of each time domain symbol; the operation processing unit is used for performing inverse Fourier transform on each effective subcarrier and a known subcarrier corresponding to each frequency domain known sequence in a known frequency domain signaling set of the time domain symbol after predetermined mathematical operation, and obtaining an inverse Fourier result corresponding to each frequency domain known sequence; and each time domain symbol is based on a selected inverse Fourier result selected from one or more inverse Fourier results by a first preset selection rule, then a plurality of time domain symbols are subjected to preset processing operation, and signaling information is solved based on the obtained inter-symbol processing result.

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

according to the preamble symbol receiving method and device provided by the embodiment of the invention, coherent demodulation can realize very robust performance under multipath channels and low signal-to-noise ratio, so that compared with a method of directly analyzing difference by using frequency domains of front and rear symbols, amplification noise is avoided, and in addition, the relative displacement of the operation structures of the front and rear symbols is further used, the problem of misjudgment when channel estimation is not accurate or interference paths occur due to various reasons is solved, and the system accuracy is improved.

Drawings

Fig. 1 is a flowchart illustrating a preamble symbol receiving method according to a first embodiment of the present invention;

fig. 2 is a schematic flowchart illustrating signaling analysis in a preamble symbol receiving method according to a first embodiment of the present invention;

FIG. 3 is a diagram illustrating a time-domain structure of a physical frame in an embodiment of the invention;

fig. 4 is a schematic diagram of a physical frame structure including a format control part and a content control part in an embodiment of the present invention;

fig. 5 is a schematic frequency domain diagram corresponding to a time domain symbol in a preamble symbol according to an embodiment of the present invention;

FIG. 6 is a schematic illustration of a first three-stage structure in an embodiment of the invention;

FIG. 7 is a schematic illustration of a second three-segment configuration in an embodiment of the present invention;

FIG. 8 is a waveform diagram of an inverse Fourier result of a time-domain subject signal under AWGN according to a first embodiment of the invention;

FIG. 9 is a waveform diagram of an inverse Fourier result of a time domain main signal under a 0dB two-path channel according to an embodiment of the present invention;

fig. 10(a) is a waveform diagram of an inverse fourier result of a time domain main signal in a previous time domain symbol before noise filtering processing in a channel with 0dB two paths in accordance with an embodiment of the present invention;

FIG. 10(b) is a waveform diagram of an inverse Fourier result of a time domain main signal in a subsequent time domain symbol before noise filtering in a channel with two paths of 0dB according to an embodiment of the present invention;

FIG. 11(a) is a waveform diagram of an inverse Fourier result of a time domain main signal in a previous time domain symbol after noise filtering in a channel with two paths of 0dB according to an embodiment of the present invention;

fig. 11(b) is a waveform diagram of an inverse fourier result of a time domain main signal in a subsequent time domain symbol after noise filtering processing in a channel with two paths of 0dB according to an embodiment of the present invention;

fig. 12 is a schematic flowchart illustrating signaling parsing in a preamble symbol receiving method according to a second embodiment of the present invention;

FIG. 13 is a waveform diagram of an inverse Fourier result of a time-domain subject signal under AWGN according to a second embodiment of the present invention; and

fig. 14 is a schematic flowchart illustrating signaling analysis in a preamble symbol receiving method according to a third embodiment of the present invention.

Detailed Description

The inventor finds that the method and the device for receiving the preamble symbol in the prior art have low robustness under the conditions of multipath channels and low signal-to-noise ratio on the premise that the effective subcarrier carries out cyclic shift in a time domain or modulates frequency offset in a frequency domain to generate a time domain symbol for transmitting a signaling, and the signaling is analyzed by utilizing direct difference of the frequency domains of the front symbol and the rear symbol after the time domain symbol expected to be received is preliminarily interpreted and positioned; the problem of misjudgment is easy to occur when the channel estimation is not accurate or the interference path occurs due to various reasons.

In view of the above problems, the inventor has studied and provided a preamble symbol receiving method, which is suitable for a transmitting end to satisfy a predetermined transmission rule, and is characterized by comprising the following steps: judging whether a preamble symbol exists in the baseband signal obtained by processing; determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol, wherein the step of determining and analyzing comprises: carrying out Fourier transform on the time domain main signal of each time domain symbol and extracting effective subcarriers; performing inverse Fourier transform on each effective subcarrier and a known subcarrier corresponding to each frequency domain known sequence in a known frequency domain signaling set of the time domain symbol after predetermined mathematical operation, and obtaining an inverse Fourier result corresponding to each frequency domain known sequence; and each time domain symbol is based on a selected inverse Fourier result selected from one or more inverse Fourier results by a first preset selection rule, then a plurality of time domain symbols are subjected to preset processing operation, and the signaling information is solved based on the obtained inter-symbol processing result.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

< example one >

Fig. 1 is a flowchart illustrating a preamble symbol receiving method according to a first embodiment of the present invention; fig. 2 is a schematic flowchart illustrating signaling analysis in a preamble symbol receiving method according to a first embodiment of the present invention.

As shown in fig. 1, the preamble symbol receiving method in this embodiment is suitable for when the preamble symbol sending method used by the sending end satisfies a predetermined sending rule, and the preamble symbol receiving method includes the following steps:

step S1-1: judging whether a preamble symbol exists in the baseband signal obtained by processing; and

step S1-2: and determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol.

As shown in fig. 2, in determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol in step S1-2, the analyzing step of the signaling includes the following specific steps:

step S2-1-1: carrying out Fourier transform on the time domain main signal of each time domain symbol and extracting effective subcarriers;

step S2-1-2: performing inverse Fourier transform on each effective subcarrier and a known subcarrier corresponding to each frequency domain known sequence in a known frequency domain signaling set of the time domain symbol after predetermined mathematical operation, and obtaining an inverse Fourier result corresponding to each frequency domain known sequence; and

step S2-1-3: each time domain symbol is based on a selected inverse Fourier result selected from one or more inverse Fourier results by a first predetermined selection rule, then predetermined processing operations are performed between the plurality of time domain symbols, and the signaling information is solved based on the obtained inter-symbol processing results.

The following description is made with reference to fig. 3 to 7 for the predetermined transmission rule of the applicable transmitting end in the preamble symbol receiving method of the present invention.

Fig. 3 is a schematic time domain structure diagram of a physical frame in an embodiment of the present invention.

As shown in fig. 3, a physical frame sent by a sending end of this embodiment includes a preamble symbol and a data area, where the preamble symbol is located before the data area, and a two-segment physical frame structure is shown in fig. 3.

The data area is used for transmitting data information such as TS packets or IP packets.

The preamble symbol is used for fast detection to determine whether the signal transmitted in the channel is a signal expected to be received, and provides basic transmission parameters (such as FFT point number, frame type information, etc.), so that the receiving end can perform subsequent receiving processing; detecting initial carrier frequency deviation and timing error for achieving frequency and timing synchronization after compensation; emergency broadcast wakeup, etc.

Fig. 4 is a schematic diagram of a physical frame structure including a format control portion and a content control portion in an embodiment of the present invention.

As shown in fig. 4, the physical frame structure includes a preamble symbol and a data area, wherein the preamble symbol includes: the part PFC and the part PCC are controlled by the physical layer format. Of course, the preamble symbol according to the present invention is not limited to include the PFC part and the PCC part.

The format control part PFC consists of one or more time domain symbols (indicated by a hatched box in the figure), each OFDM time domain symbol being of the same size. In this embodiment, the time domain symbol is an OFDM symbol, and as can be seen from fig. 4, in this embodiment, the format control portion PFC of the transmitting end includes four time domain symbols.

FIG. 6 is a schematic illustration of a first three-stage structure in an embodiment of the invention; and FIG. 7 is a schematic illustration of a second three-stage configuration in an embodiment of the present invention.

The format control part PFC of the preamble symbol includes at least one time domain symbol, and since the time domain symbol in this embodiment adopts the following first three-segment structure or second three-segment structure, the time domain symbol included in the preamble symbol may also be referred to as a three-segment structure time domain symbol. However, without limitation, the time domain symbols satisfying the above-mentioned preamble symbol may also adopt other structures other than the three-segment structure.

As can be seen from fig. 6 and fig. 7, in the first embodiment, the time domain symbol has the following three-stage structure: a first three-stage structure as in fig. 6: the method comprises the steps of firstly, generating a time domain main signal (A section), generating a prefix (C section) based on the rear part of the time domain main signal, and selecting a part of generated suffix (B section) in the prefix range based on the time domain main signal; a second three-stage structure as in fig. 7: the method comprises the steps of generating a time domain main signal (A section), generating a prefix (C section) based on the rear part of the time domain main signal, and selecting a part of generated prefix (B section) in a prefix range based on the time domain main signal.

A time domain body signal (denoted by a in the figure) is used as a first part, a part is taken out according to a preset acquisition rule at the tail end of the first part, the first part is processed and copied to the front part of the first part to generate a third part (denoted by C in the figure) to be used as a prefix, meanwhile, a part is taken out according to a preset acquisition rule from the rear part of the first part, the predetermined processing is processed and copied to the rear part of the first part or the predetermined processing is copied to the front part of the prefix to generate a second part (denoted by B in the figure) to be respectively used as a suffix or a super prefix, and therefore, a first three-segment structure (CAB structure) with B as a suffix and a second three-segment structure (BCA structure) with B as a super prefix shown in fig. 6 are respectively generated, and the second three-segment structure (BCA structure) shown.

Based on the time domain symbol having the three-segment structure, the preamble symbol generated in this embodiment may include: a time domain symbol having a first three-segment structure; or a time domain symbol having a second three-segment structure; or a plurality of time domain symbols with the first three-segment structure and/or a plurality of time domain symbols with the second three-segment structure which are not arranged in sequence are freely combined. That is, the preamble symbol may only contain CAB or BCA, or may be several CABs or several BCAs, or may be any arbitrary combination of several CABs and several BCAs without limitation in number. It should be particularly noted that the preamble symbol of the present invention is not limited to a structure containing only C-a-B or B-C-a, but may also contain other time domain structures, such as a conventional CP structure.

The section A is obtained by performing IFFT transform of 2048 points, for example, on the basis of a certain frequency domain main body sequence, and the section C in the three-section structure is a direct copy of a part in the section A, while the section B is a modulation signal section of a part in the section A, and the data range of the section B does not exceed the data range of the section C, namely, the range of the part A selected to the modulation signal section B does not exceed the range of the part A intercepted as the prefix C. Preferably, the sum of the length of B and the length of C is the length of a.

Let N_ALet Len be the length of A_CIs the length of C, Len_BIs the length of the modulation signal segment B. Let the sampling point number of A be 0,1, … N_ALet N1 be the sample point number selected to be copied to the first portion a corresponding to the start of the second portion B of the modulation signal segment, and N2 be the sample point number selected to be copied to the first portion a corresponding to the end of the second portion B of the modulation signal segment. Wherein,

N2＝N1+Len_B-1 (formula 1)

In general, the modulation applied to the second part B segment is modulation frequency offset, modulation M sequence or other sequences, etc., in this implementation, taking modulation frequency offset as an example, if P1_ a (t) is a time domain expression of a, the time domain expression of the first common preamble symbol is

$P_{C-A-B}\left(t\right)=\left\{\begin{array}{cc}P1\_A(t+(N_A-{\mathrm{Len}}_C)T)& 0\&le;t<{\mathrm{Len}}_{C}T\\ P1\_A(t-{\mathrm{Len}}_{C}T)& {\mathrm{Len}}_{C}T\&le;t<(N_A+{\mathrm{Len}}_C)T\\ P1\_A(t-({\mathrm{Len}}_C+N_A-N1)T)e^{j2\mathrm{\&pi;}{f}_{\mathrm{SH}}t}& (N_A+{\mathrm{Len}}_C)T\&le;t<(N_A+{\mathrm{Len}}_C+{\mathrm{Len}}_B)T\\ 0& \mathrm{otherwise}\end{array}\right.$

(formula 2)

Wherein, the modulation frequency deviation value f_SHCan be selected as the frequency domain subcarrier interval corresponding to the time domain OFDM symbol, namely 1/N_AT, or 1/(Len)_B+Len_c) T where T is the sampling period, N_AIs the length of a time domain OFDM symbol, e.g., N_AIs 1024, take f_SH1/1024T, and the modulation frequency offset may be arbitrarily chosen for the initial phase. To sharpen the correlation peak, f_SHCan also be selected to be 1/(Len)_BT) or a value close to its value.

In the structure of B-C-A, the modulation frequency deviation value is just opposite to that of the structure of C-A-B, and the modulation can be arbitrarily selected as an initial phase.

$P_{B-C-A}\left(t\right)=\left\{\begin{array}{cc}P1\_A(t+\left(N1\right)T)e^{-j2\mathrm{\&pi;}{f}_{\mathrm{SH}}\left(t{-\mathrm{Len}}_{C}T\right)}& 0\&le;t<{\mathrm{Len}}_{B}T\\ P1\_A(t-({\mathrm{Len}}_B-N_A+{\mathrm{Len}}_C)T)& {\mathrm{Len}}_{B}T\&le;t<({\mathrm{Len}}_B+{\mathrm{Len}}_C)T\\ P1\_A(t-({\mathrm{Len}}_B+{\mathrm{Len}}_C)T)& ({\mathrm{Len}}_B+{\mathrm{Len}}_C)T\&le;t<({\mathrm{Len}}_B+{\mathrm{Len}}_C+N_A)T\\ 0& \mathrm{otherwise}\end{array}\right.$

(formula 3)

Setting the serial number of a first sampling point corresponding to the first part (A) and selecting the starting point of the second part (B) in the first three-segment structure (CAB) as N1_1, setting the serial number of a second sampling point corresponding to the first part (A) and selecting the starting point of the second part (B) in the second three-segment structure (BCA) as N1_2, wherein the serial numbers of the first sampling point N1_1 and the second sampling point N1_2 need to satisfy the following formula

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

The advantage of satisfying such a relationship is that the delay relationship of the same content from segment C to segment B in the C-A-B structure is the same as the delay relationship of the same content from segment B to segment A in the B-C-A structure, and the delay relationship of the same content from segment A to segment B in the C-A-B structure is the same as the delay relationship of the same content from segment B to segment C in the B-C-A structure, which is beneficial for the receiver implementation. And in the C-A-B structure and the B-C-A structure, if the modulation adopted for the B section is modulation frequency offset, the frequency offset values f of the two structures_SHBut just the opposite, facilitates the receiver implementation.

The symbol of C-A-B structure is represented by the symbol No. 1, and the symbol of B-C-A structure is represented by the symbol No. 2. Then, let P1_ A (t) be the time domain expression of A1, P2_ A (t) be the time domain expression of A2, and then the time domain expression of the C-A-B three-segment structure is

$P1\left(t\right)=\left\{\begin{array}{cc}P1\_A(t+(N_A-{\mathrm{Len}}_C)T)& 0\&le;t<{\mathrm{Len}}_{C}T\\ P1\_A(t-{\mathrm{Len}}_{C}T)& {\mathrm{Len}}_{C}T\&le;t<(N_A+{\mathrm{Len}}_C)T\\ P1\_A(t-({\mathrm{Len}}_C+N_A-N1\_1)T)e^{j2\mathrm{\&pi;}{f}_{\mathrm{SH}}t}& (N_A+{\mathrm{Len}}_C)T\&le;t<(N_A+{\mathrm{Len}}_C+{\mathrm{Len}}_B)T\\ 0& \mathrm{otherwise}\end{array}\right.$

(formula 5)

The time domain expression of the three-section structure of B-C-A is as follows

$P2\left(t\right)=\left\{\begin{array}{cc}P2\_A(t+(N1\_2)T)e^{-j2\mathrm{\&pi;}{f}_{\mathrm{SH}}\left(t{-\mathrm{Len}}_{C}T\right)}& 0\&le;t<{\mathrm{Len}}_{B}T\\ P2\_A(t-({\mathrm{Len}}_B-N_A+{\mathrm{Len}}_C)T)& {\mathrm{Len}}_{B}T\&le;t<({\mathrm{Len}}_B+{\mathrm{Len}}_C)T\\ P2\_A(t-({\mathrm{Len}}_B+{\mathrm{Len}}_C)T)& ({\mathrm{Len}}_B+{\mathrm{Len}}_C)T\&le;t<({\mathrm{Len}}_B+{\mathrm{Len}}_C+N_A)T\\ 0& \mathrm{otherwise}\end{array}\right.$

(formula 6)

The first three-segment structure and the second three-segment structure which are arranged in sequence are not distinguished, and different leading symbols which are freely combined by a plurality of first three-segment structures and/or a plurality of second three-segment structures can be respectively formed according to different sequences. The time domain expression of a first preamble symbol, which is 1C-a-B and 1B-C-a in order, and the time domain expression of a second preamble symbol, which is 1B-C-a and 1C-a-B in order, are given below by way of example.

Then, the time domain expression of the first preamble symbol is:

(formula 7)

The time domain expression of the second preamble symbol is:

(formula 8)

Other combinations of C-A-B and B-C-A can be deduced according to the time domain expression of the first preamble symbol and the second preamble symbol, and repeated description is omitted here.

As in the above case, when the C-a-B structure and the B-C-a structure are cascaded, the problem of small bias estimation failure under a dangerous delay can be solved. When the critical delays cause the cancellation of the C and a segments, the CB segment of the first structure and the BC segment of the second structure can still be used for timing synchronization and estimation bias.

The number of at least one time domain symbol contained in the preamble symbol is set to transmit four symbols, and several preferred four time domain symbol structures are given below and are arranged in sequence as any one of the following structures:

(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。

Among them, the structure of four time domain symbols, such as (1) C-A-B, B-C-A, maximizes the effect of concatenation. For example, (2) the structure of four time domain symbols, C-A-B, B-C-A, B-C-A, B-C-A, lengthens the guard interval of the subsequent symbol A portion, and typically the first symbol is a known signal, so C-A-B is used.

One preferred embodiment of a three-stage structure, N_A2048, let Len_CIs 520, Len_BWhere P1_ a (t) is the temporal body a expression, 504, N1_1 is 1544, N1_2 is 1528, it can be derived that the temporal expressions of C-a-B and B-C-a are the same

$P_{C-A-B}\left(t\right)=\left\{\begin{array}{cc}P1\_A(t+1528T)& 0\&le;t<520T\\ P1\_A(t-520T)& 520T\&le;t<2568T\\ P1\_A(t-1024T)e^{j2\mathrm{\&pi;}{f}_{\mathrm{SH}}t}& 2568T\&le;t<3072T\\ 0& \mathrm{otherwise}\end{array}\right.$

(formula 9)

And

$P_{B-C-A}\left(t\right)=\left\{\begin{array}{cc}P1\_A(t+1528T)e^{-j2\mathrm{\&pi;}{f}_{\mathrm{SH}}(t-520T)}& 0\&le;t<504T\\ P1\_A(t+1024T)& 504T\&le;t<1024T\\ P1\_A(t-1024T)& 1024T\&le;t<3072T\\ 0& \mathrm{otherwise}\end{array}\right.$

(formula 10)

Further, f_SHIt can be selected as 1/(1024T) or 1/(2048T).

Further, the emergency broadcast system may be identified by selecting a different starting point for the second part B from the first part a, i.e. by selecting a different N1, or N1_1 and N1_2, by copying to the starting point of the B segment. A symbol of a three-segment structure such as C-a-B, N1_ 1-1544 identifies a general system, and N1_ 1-1528 identifies an emergency broadcast system. For another example, in the notation of the three-segment structure of B-C-a, N1_2 ═ 1528 identifies a general system, and N1_2 ═ 1544 identifies an emergency broadcast system.

The method for generating the preamble symbol of the transmitting end comprises the following steps:

the method comprises the steps of generating frequency domain subcarriers based on a frequency domain main body sequence, carrying out inverse Fourier transform (IFFT) on the frequency domain subcarriers to obtain a time domain main body signal A, and forming a time domain symbol with a three-section structure of C-A-B or B-C-A by the time domain main body signal A, so that a preamble symbol with at least one time domain symbol in the embodiment is formed.

The generation process in the time domain main body signal a of a three-segment structure (CAB or BCA) is described below from a frequency domain perspective in conjunction with fig. 5.

Fig. 5 is a schematic frequency domain diagram corresponding to one time domain symbol in the preamble symbol according to the embodiment of the present invention.

As shown in fig. 5, a frequency domain subcarrier of a time domain symbol in PFC, which gives a preamble symbol, is generated, and the frequency domain subcarrier is obtained based on a frequency domain subject sequence.

The generation of the frequency domain subcarriers includes a predetermined sequence generation rule for generating a frequency domain subject sequence and/or a predetermined processing rule for processing the frequency domain subject sequence to generate the frequency domain subcarriers.

For a predetermined sequence generation rule, the generation process of the frequency domain subject sequence is flexible, and the predetermined sequence generation rule includes any one or a combination of two of the following: generating based on different sequence generating formulas; and/or based on the same sequence generating formula, and further performing cyclic shift on the generated sequence. In this embodiment, the constant envelope zero autocorrelation sequence (CAZAC sequence) is used, that is, the different sequence generating equations may be obtained by assigning different root values to the same CAZAC sequence, or the same sequence generating equation may be obtained by assigning the same root value to the CAZAC sequence.

The frequency domain subject sequence is generated based on one or more CAZAC sequences, the frequency domain subject sequence having a predetermined sequence length N_ZC. The predetermined sequence length N_ZCNot greater than the Fourier transform length N that the time domain subject signal has_FFT。

The step of processing and filling the frequency domain subject sequence generally comprises: with reference to a predetermined sequence length N_ZCMapping the frequency domain main body sequence into a positive frequency subcarrier and a negative frequency subcarrier; with reference to the Fourier transform length N_FFTFilling a preset number of virtual subcarriers and direct current subcarriers at the outer edges of the positive frequency subcarriers and the negative frequency subcarriers; and circularly left-shifting the obtained subcarriers so thatThe zero subcarrier corresponds to the first position of the inverse fourier transform.

Here, an example of generation based on one CAZAC sequence is described. First, N is generated_ZCA long frequency domain body sequence (Zadoff-Chu, sequence, ZC), which is one of the CAZAC sequences,

the sequence formula is: $a_q\left(n\right)=e^{-\mathrm{j\&pi;q}\frac{n(n+1)}{N_{\mathrm{root}}}}$

(formula 11)

Note N_ZCMay be equal to or less than N_rootThe ZC _ M sequence is divided into two parts, the left half part has the length ofMapped to the negative frequency part, the right half length isMapping to a positive frequency part, N_ZCA certain natural number can be selected, and the FFT length of the section A is not exceeded; in addition, at the edge of negative frequency, complementNumber of zeros, and edge of positive frequencyTo supplementThe number of zeros, being virtual subcarriers; thus, the specific sequence is composed ofThe number of the zero lines is zero,a number of PN modulated ZC sequences, 1 dc subcarrier,a PN modulated ZC sequence andeach zero is composed sequentially; number of effective subcarriers is N_ZC+1。

In particular, the generation of frequency domain subject sequences, such as sequence formulasSeveral different root values q can be selected, for the sequence generated by each root value q, different cyclic shifts can be performed to obtain more sequences, and the signaling is transmitted by any one or two of the 2 ways.

For example, taking 256 root values q, 256 sequences are obtained, i.e. 8 bits can be transmitted, based on 2^8 ^ 256 and the shift value is set to 1024, each of the 256 sequences can perform 0-1023 shifts again, i.e. each sequence realizes 10-bit signaling transmission through 1024 shifts, based on 2^10 ^ 1024, thus 8+10 ^ 18-bit signaling can be transmitted altogether.

These signallings are mapped to bit fields, and the transmitted signallings can contain frame format parameters for indicating physical frames and/or for indicating emergency broadcast contents, wherein the frame format parameters are as follows: the frame number, the frame length, the bandwidth of the PCC symbol, the bandwidth of the data region, the FFT size and guard interval length of the PCC symbol, and the PCC modulation and coding parameters.

The cyclic shift in the predetermined sequence generation rule may be performed before the PN sequence modulation is performed on the ZC sequence, or may be performed after the PN sequence modulation, and PN sequences used for the PN modulation are the same or different for the frequency domain main body sequences corresponding to the time domain main body signals.

If the first time domain main signal in the at least one time domain main signal adopts a pre-known frequency domain main sequence, the frequency domain main sequence and the corresponding frequency offset value are not used for signaling transmission, and signaling is transmitted by the PFC in a subsequent time domain symbol.

The phase difference between the frequency domain main body sequence (ZC sequence) used by the last OFDM symbol and the frequency domain main body sequence (ZC sequence) used by the first OFDM symbol is 180 degrees, which is used for indicating the last OFDM symbol of PFC; the ZC sequence used for the first OFDM symbol in the PFC is generally a root sequence with a certain length and without cyclic shift, and at this length, the ZC sequence has a set, so that the ZC sequence in the set is selected by the present invention, which may indicate certain information, such as a version number or indicate a type or mode of a service transmitted in a data frame; in addition, information is transmitted by using the corresponding root value in the first time domain main body signal and/or the initial phase of the PN sequence for PN modulation, and the initial phase of the PN also has a certain signaling capability, such as indicating a version number.

Here, an example of generation based on a plurality of CAZAC sequences is described. Each CAZAC sequence has a corresponding sub-sequence length L_MGenerating a sequence having a subsequence length L for each CAZAC sequence according to the predetermined sequence generation rule_MA plurality of subsequences are spliced to have a predetermined sequence length N_ZCThe frequency domain body sequence of (1).

Specifically, the frequency domain effective subcarriers are generated by M CAZAC sequences each having a length L₁,L₂,...L_MAnd satisfyThe generation method of each CAZAC sequence is the same as the above method, only one step is added, and after M CAZAC sequences are generated, the M CAZAC sequences are spliced into a sequence with the length of N_ZCThe selected ZC _ M is modulated by PN sequence to form new ZC _ I, which is then interleaved in frequency domain to fill in the same sub-carrier position and has the length of the left half partMapped to the negative frequency part, the right half length isMapping to a positive frequency part, N_ZCA certain natural number can be selected, and the FFT length of the section A is not exceeded; in addition, at the edge of negative frequency, complementNumber of zeros, and at the edges of positive frequencies, complementThe number of zeros, being virtual subcarriers; thus, the specific sequence is composed ofThe number of the zero lines is zero,a number of PN modulated ZC sequences, 1 dc subcarrier,a PN modulated ZC sequence andzero sequence, wherein the step of modulating PN may also be performed after frequency domain interleaving.

The subcarrier position padding may also take other processing padding steps, which are not limited herein.

The sub-carriers obtained by the processing and filling are circularly moved to the left, and after the first half and the second half of the frequency spectrum are exchanged, the zero sub-carrier is corresponding to the first position of the discrete inverse Fourier transform to obtain the preset length N similar to the ftshift in Matlab_FFTThe pre-generated subcarriers of the frequency domain OFDM symbol of (1).

Further, in the frequency domain subcarrier generation process of the present embodiment, in addition to the above-described predetermined sequence generation rule, a predetermined processing rule for processing the frequency domain subject sequence to generate the frequency domain subcarriers may be more preferably adopted. The present invention is not limited to forming the frequency domain subcarriers using either or both of the predetermined processing rule and the predetermined sequence generation rule.

The predetermined processing rule includes: and performing phase modulation on the pre-generated subcarrier according to the frequency offset value S, wherein the pre-generated subcarrier is obtained by processing, filling, circulating, left shifting and the like on the frequency domain main body sequence. In the predetermined processing rule, the frequency domain subcarriers corresponding to the same time domain main signal a perform phase modulation on each effective subcarrier in the frequency domain subcarriers by using the same frequency offset value S, and the frequency offset values used by the frequency domain subcarriers corresponding to different time domain main signals a are different from each other by S.

For a predetermined processing rule, specifically, the subcarrier expression of the original OFDM symbol is

a₀(k) k＝0,1,2,...N_FFT-1，

(equation 12) the expression for phase modulating each subcarrier by a certain frequency offset value, such as s, is as follows:

$\begin{array}{cc}{a}_s\left(k\right)=a_0\left(k\right)\&CenterDot;e^{j\frac{2\mathrm{\&pi;sk}}{N_{\mathrm{FFT}}}}& k=\mathrm{0,1,2},...N_{\mathrm{FFT}}-1\end{array}$

(formula 13)

The zero carrier multiplication operation is actually not required to be carried out, and only the effective subcarriers are required to be operated. The frequency offset value s may be selected within a range [ - (N)_FFT-1),+(N_FFT-1)]Based on the fourier transform length N that the time domain subject signal has_FFTAnd determining that different values can be used for transmitting signaling.

It should be noted that the above-mentioned method for performing phase modulation on each pre-generated subcarrier according to the frequency offset value S can also be implemented in the time domain. Equivalent to: the original frequency domain OFDM symbol without the modulation phase is subjected to IFFT conversion to obtain a time domain ODFM symbol, the time domain OFDM symbol can be subjected to cyclic shift to generate a time domain main signal A, and signaling is transmitted through different cyclic shift values. In the present invention, each effective subcarrier is phase-modulated at a certain frequency offset value in the frequency domain, and the obvious time domain equivalent operation method is also within the present invention.

In summary, in the generation process of the frequency domain subcarriers, the present embodiment may select and freely combine any one or at least two of the predetermined sequence generation rule (1a), the predetermined sequence generation rule (1b) and the predetermined processing rule (2) based on the frequency domain subject sequence.

For example, the preamble symbol generation method of rule (1a) is adopted to transmit signaling.

Taking 256 root values q and 0-1023 cyclic shift values for each root value q as described in the above example, 8+ 10-18 bit signaling may be transmitted.

For another example, the generation method of the preamble symbol of rule (1a) and rule (2) is used to transmit signaling.

The root value q takes 2 types, the time domain OFDM symbol length is 2048, 1024 types of shift values are taken, and 1+10 ═ 11 bit signaling is transmitted at intervals of 2, such as 0, 2, 4, 6, …, 2046 and the like.

For another example, only the preamble symbol generation method of rule (2) is used.

The root value q is fixed, and the phase modulation is carried out on the frequency domain subcarrier according to different frequency offset values S, such as the N_FFTIn the range of 2048 (parts by weight),s is 0, 8, 16, … 2032, etc., which is equivalent to a time domain OFDM symbol after IFFT is performed on a frequency domain OFDM symbol without phase modulation, cyclic shift is performed on 256 different shift values, and 8-bit signaling is transmitted at 8 intervals, such as 0, 8, 16, … 2032, etc. Here, the present invention does not limit the left shift or the right shift of the cyclic shift, and when s is a positive number, the left shift corresponds to the time domain cyclic shift, for example, the value is 8, and the left shift corresponds to the time domain cyclic shift 8; when s is a negative number, the corresponding time domain cycle is shifted to the right, for example, the value is-8, and the corresponding time domain cycle is shifted to the right by 8.

In addition, in the above method, the method of transmitting signaling by using frequency domain modulation frequency offset value, i.e. time domain shift value, is not limited, that is, the method includes transmitting signaling directly by using current symbol absolute shift value, and also includes transmitting signaling by using difference between shift values of previous and next symbols, and the signaling analysis of both methods can be obviously derived from one of the two methods. Meanwhile, the corresponding relation between the signaling and the shift value is not limited, the transmitting end can be freely set, and the receiving end can be reversely pushed according to the set rule. Signaling with the absolute value of the shift value for each symbol is for example as follows: for example, there are 4 PFC symbols, where the first symbol does not transmit signaling, and the signaling values to be transmitted of the second to fourth symbols are S1, S2, S3, respectively. Assuming that the shift value corresponds to a value 4 times as much as the signaling, the shift value of the second symbol is 4S1, the shift value of the second symbol is 4S2, and the shift value of the third symbol is 4S 3; signaling using the difference between the shift values of the previous and next symbols is as follows: for example, there are 4 PFC symbols, where the first symbol does not transmit signaling, and the signaling values to be transmitted of the second to fourth symbols are S1, S2, S3, respectively. Assuming that the shift value corresponds to a value 4 times as much as the signaling, the shift value of the second symbol is 4S1, the shift value of the second symbol is 4(S1+ S2), and the shift value of the third symbol is 4(S1+ S2+ S3);

the predetermined transmission rule of the transmitting end to which the preamble symbol receiving method of the present invention is applied is described above with reference to fig. 3 to 7.

The present invention explains the algorithm for receiving preamble symbols by the first embodiment, the second embodiment and the third embodiment, respectively, and the mean value of all the embodiments is that no matter the receiving end generates different sequences based on different sequence generating formulas or generates different sequences based on the same sequence generating formula, then performs cyclic shift to obtain different sequences, the receiving method set forth in the present invention does not distinguish these 2 cases, and is not always uniformly called to transmit signaling by using different frequency domain sequences.

In general, the predetermined transmission rule to be satisfied includes that after a frequency domain subject sequence corresponding to a time domain subject signal in each time domain symbol to be transmitted is processed to obtain a generated pre-generated subcarrier, each effective subcarrier is subjected to phase modulation or inverse fourier transform with a predetermined frequency offset value S in a frequency domain, and then cyclic shift is performed in the time domain.

Continuing to describe the first embodiment, the time domain main signal a corresponding to each PFC symbol is subjected to FFT operation to obtain a frequency domain signal, the frequency domain signal is taken out of a value of an effective subcarrier, each subcarrier is subjected to predetermined mathematical operation with a subcarrier corresponding to each frequency domain known sequence of the symbol known frequency domain signaling set, IFFT operation is performed, each frequency domain known sequence corresponds to an IFFT result, each symbol selects one IFFT result that is most reliable for each symbol based on one or more IFFT results, and can perform predetermined processing, and then a certain operation between symbols is performed to solve transmitted signaling information (including different frequency domain sequence transmission signaling and/or frequency domain modulation signaling, that is, signaling transmitted by time domain cyclic shift values) by using processing results between multiple symbols.

The known frequency domain signaling set here comprises: the body signal a for each PFC symbol is padded to all possible sequences of the frequency-domain sequence of subcarriers before the frequency-domain subcarrier modulation phase. If the transmitting end has modulation PN operation, all possible frequency domain sequences after PN modulation are referred to.

When the symbol known frequency domain signaling set has only one known sequence, that is, only depends on the signaling transmitted by the frequency domain modulation frequency offset, that is, the time domain cyclic shift value, the analysis method in the receiving method in the first embodiment can be simplified as follows:

performing FFT operation on a time domain main signal A corresponding to each PFC time domain symbol to obtain a frequency domain signal, taking out the value of an effective subcarrier from the frequency domain signal, performing certain operation (conjugate multiplication/division operation) on each effective subcarrier and the effective subcarrier corresponding to the unique known frequency domain sequence corresponding to the symbol, performing IFFT operation, optionally performing preset processing based on the IFFT result, and further performing preset processing operation between time domain symbols to solve transmitted signaling (frequency domain modulation frequency offset, namely signaling transmitted by a time domain cyclic shift value) by using the IFFT result of processing between a plurality of symbols.

Specifically, for a certain PFC symbol, the expression of a given transmission frequency domain pre-generated subcarrier before phase modulation is known as A_kAfter phase modulation, the expression is

${\mathrm{AM}}_k=A_k\&CenterDot;e^{j\frac{2\mathrm{\&pi;sk}}{N_{\mathrm{FFT}}}},$ (formula 14)

Wherein H_kFor the channel frequency domain response, after the channel, the received frequency domain data is expressed as

$R_k={\mathrm{AM}}_k\&CenterDot;H_k+N_k=A_k\&CenterDot;H_k\&CenterDot;e^{j\frac{2\mathrm{\&pi;sk}}{N_{\mathrm{FFT}}}}+N_k,k=\mathrm{0,1},....N_{\mathrm{FFT}}-1$ (formula 15)

The predetermined mathematical operation (conjugate multiplication/division operation) employed in the present implementation is performed,

or E_k＝R_k·(A(i)_k)^*(formula 16)

Wherein, A (t)_kT-th known sequence, T1, T, representing the set of known frequency domain sequences of the PFC symbol, is a total of T sequences.

If there is only one known sequence in the known frequency domain sequence set, i.e. T ═ 1, then a (1)_k＝A_k. For example, usingA predetermined mathematical operation of division, when the set of known frequency domain sequences has only one known sequence, then deriving ${E\left(1\right)}_k=\frac{R_k}{{A\left(1\right)}_k}=H_k\&CenterDot;e^{j\frac{2\mathrm{\&pi;sk}}{N_{\mathrm{FFT}}}}+\frac{N_K}{A_k},$ (formula 17)

The physical meaning is the product of the channel estimation value and the modulation phase value of each subcarrier; and another formula of predetermined mathematical operation ${E\left(1\right)}_k=R_k\&CenterDot;{\left({A\left(1\right)}_k\right)}^{*}=H_k\&CenterDot;{\left|A_k\right|}^2{e}^{j\frac{2\mathrm{\&pi;sk}}{N_{\mathrm{FFT}}}}+N_k\&CenterDot;{A_k}^{*},$ (formula 18)

Also including the product of the channel estimate and the modulation phase value for each subcarrier.

Then E (t)_k，k＝0,1,....N_FFT-1, performing IFFT operation, so that each PFC symbol will obtain T IFFT operation results, optionally performing an operation of taking an absolute value or taking a square of the absolute value on the results, and then selecting the most reliable one of T results of T ═ 1.. T as the operation result of the PFC symbol according to a first predetermined selected rule, where the corresponding T value can solve the signaling transmitted by different sequences in the frequency domain. The most reliable determination method according to the first predetermined selection rule may be peak-to-peak or peak-to-average ratio.

If the known frequency domain sequence set of each PFC symbol has only 1 known sequence, the step of selecting the most reliable one of the T results as the operation result of the symbol can be omitted, and the unique IFFT result of each symbol can be directly used as the IFFT selection result.

Fig. 8 is a waveform diagram of an inverse fourier result of a time-domain subject signal under AWGN in a first embodiment of the present invention. The maximum discrete inverse fourier transform is shown as 1049, which has a value of 1.024.

Then, assuming that the PFC has Q symbols, the following waveform c (Q) of Q symbols is obtained, Q being 1. Note that c (q) may be the result of some original IFFT chosen from the T results, or may be the result of taking the absolute value or the square of the absolute value.

Considering the influence of noise and multipath, and the influence of interference paths for various reasons, for example, 2 peaks are present at 0dB two paths, and the maximum peak is not well judged, fig. 9 provides a waveform diagram of the inverse fourier result of a time domain main signal at the channel of 0dB two paths in one embodiment.

Therefore, as shown in fig. 9 below, the inverse fourier operation result of each time domain symbol may be further subjected to noise filtering, i.e., a large value is retained, and all small values are set to zero, which is optional. The processing results corresponding to all PFC symbols are obtained, and are named as C' (Q), Q1.

A schematic of C '(q-1) and C' (q) before and after 2 symbol processing in the 0dB two-path channel is given below. Fig. 10(a) and 10(b) are waveform diagrams of the inverse fourier result of the time domain main signal in the previous time domain symbol and the next time domain symbol respectively before the noise filtering process in the channel with two paths of 0dB in the first embodiment; fig. 11(a) and 11(b) are waveform diagrams of the inverse fourier result of the time domain main signal in the previous time domain symbol and the next time domain symbol after the noise filtering process in the channel with 0dB two paths, respectively, in the first embodiment.

And then circularly shifting the C '(q) of the next symbol, multiplying or conjugatively multiplying and accumulating the C' (q-1) of the previous symbol, finding out the one with the largest accumulated value in all the shift values, and calculating the transmitted signaling by the corresponding shift value, wherein the transmitted signaling is realized by performing phase modulation on each effective subcarrier according to the S value after generating a pre-generated subcarrier by a frequency domain sequence of a main signal A corresponding to a PFC symbol, namely equivalently performing cyclic shift on a time domain OFDM symbol after IFFT.

A specific description of the predetermined processing operation between the time domain symbols is as follows, C '(q) is cyclically shifted by V to obtain C' (q, V), optionally left or right shifted, in this case right shifted, V ∈ [0, N_FFT-1]And then a conjugate multiplication and accumulation operation such as the following formula is performed,

$\mathrm{Accum}\left(V\right)=\underset{i=0}{\overset{N_{\mathrm{FFT}}-1}{\mathrm{\&Sigma;}}}{C}^{\&prime;}(q-1)\&CenterDot;\mathrm{conj}\left(C^{\&prime;\&prime;}(q,V)\right)$ (formula 19)

It should be noted that the predetermined processing operation performed between the time domain symbols is only an example, and is not limited to conjugate multiplication, and the multiplication and accumulation operations may not be N_FFTAnd (4) point counting, namely, only a few large-value points are required.

Finally, the largest Accum (V) is selected, and the corresponding V value can deduce the signaling transmitted by the frequency domain modulation frequency offset, i.e. the time domain cyclic shift value, and the derivation method is not limited here.

< example two >

Fig. 12 is a schematic diagram illustrating a signaling parsing flow in a preamble symbol receiving method according to a second embodiment of the present invention, where the signaling parsing flow is included in the same preamble symbol receiving method as that according to the first embodiment in fig. 1, and an overall outline of the preamble symbol receiving method is omitted in the second embodiment, and fig. 12 is another embodiment of fig. 2.

As shown in fig. 12, in step S1-2, determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol, the signaling analyzing step includes the following specific steps:

step S2-2-1: carrying out Fourier transform on the time domain main signal of each time domain symbol and extracting effective subcarriers;

step S2-2-2: performing inverse Fourier transform on each effective subcarrier and a known subcarrier corresponding to each frequency domain known sequence in a known frequency domain signaling set of the time domain symbol and a channel estimation value after performing predetermined mathematical operation, and obtaining an inverse Fourier result corresponding to each frequency domain known sequence; and

step S2-2-3: each time domain symbol is used to solve signaling information directly and/or using a predetermined processing operation between a plurality of time domain symbols based on a selected inverse fourier result selected from one or more inverse fourier results with a first predetermined selected rule, and to solve signaling information based on the resulting inter-symbol processing result.

For the predetermined sending rule of the applicable sending end, the receiving method of the preamble symbol in the second embodiment is also applicable to the description given in fig. 3 to fig. 7, and is not described again.

In the second embodiment, a time domain main signal a corresponding to each PFC symbol is subjected to FFT operation to obtain a frequency domain signal, the frequency domain signal is extracted to obtain a value of an effective subcarrier, after performing predetermined mathematical operation (conjugate multiplication/division operation) on each effective subcarrier, the effective subcarrier corresponding to each frequency domain known sequence of the symbol-known frequency domain signaling set and a channel estimation value, IFFT operation is performed, each frequency domain known sequence corresponds to an IFFT result, each symbol selects, according to a predetermined selection rule, an IFFT selected result that is most reliable for each symbol based on one or more IFFT results, and optionally performs predetermined processing, and the IFFT selected result is used to directly obtain a signaling transmission value, or further performs predetermined processing operation (such as delay correlation) between time domain symbols to solve transmitted signaling (including transmission signaling of different frequency domain sequences and/or frequency domain modulation signaling) by using processing results between a plurality of symbols Frequency offset, i.e., signaling conveyed by the time domain cyclic shift value).

The known frequency domain signaling set refers to all possible sequences of the frequency domain sequence in which the main signal a corresponding to each PFC symbol is filled to the subcarrier before the modulation phase of the frequency domain subcarrier, for example, a transmitting end has a PN modulation operation, and here refers to all possible frequency domain sequences after PN modulation.

When the symbol-known frequency domain signaling set has only one known sequence, that is, signaling is transmitted only by relying on frequency domain modulation frequency offset, that is, time domain cyclic shift value, the second embodiment can be simplified as follows:

performing FFT operation on a time domain main signal A corresponding to each PFC time domain symbol to obtain a frequency domain signal, taking out a value of an effective subcarrier from the frequency domain signal, performing predetermined mathematical operation (conjugate multiplication/division operation) on the subcarrier corresponding to each effective subcarrier and a unique known frequency domain sequence corresponding to the time domain symbol and a channel estimation value, performing IFFT operation, and optionally performing predetermined processing based on the IFFT result, wherein the IFFT operation can be used for directly obtaining a signaling transmission value, and can also be used for further performing delay correlation among symbols to solve the transmitted signaling (the signaling transmitted by a frequency domain modulation frequency offset, namely a cyclic shift value of a time domain) by utilizing the processing result among a plurality of symbols.

Specifically, for a certain PFC time domain symbol, the expression of a known transmission frequency domain pre-generated subcarrier of a main body time domain signal A before phase modulation is A_kAfter phase modulation, the expression is

${AM}_k=A_k\&CenterDot;e^{j\frac{2\mathrm{\&pi;sk}}{N_{\mathrm{FFT}}}},$ (formula 20)

Wherein H_kFor the channel frequency domain response, after the channel, the received frequency domain data is expressed as

$R_k={\mathrm{AM}}_k\&CenterDot;H_k+N_k=A_k\&CenterDot;H_k\&CenterDot;e^{j\frac{2\mathrm{\&pi;sk}}{N_{\mathrm{FFT}}}}+N_k,k=\mathrm{0,1},....N_{\mathrm{FFT}}-1$ (formula 21)

Then, a predetermined mathematical operation (division/conjugate multiplication) is performed

Or E_k＝R_k·(A(t)_k·H_est,k)^*(formula 22)

Wherein A (t)_kThe tth known sequence representing the set of known frequency domain sequences. T1.. T, for a total of T sequences. If there is only one known sequence in the known frequency domain sequence set, i.e. T ═ 1, then a (1)_k＝A_kIn which H is_estIs a channel estimate.

For example, the predetermined mathematical operation isWhen there is only one known sequence in the set of known frequency domain sequencesAnd when H is_estWhen the carbon content is equal to H,

then ${E\left(1\right)}_k=\frac{R_k}{{A\left(1\right)}_k\&CenterDot;H_{\mathrm{est},k}}=e^{j\frac{2\mathrm{\&pi;sk}}{N_{\mathrm{FFT}}}}+\frac{N_K}{A_k\&CenterDot;H_{\mathrm{est},k}},$ (formula 23)

The physical meaning of which is the modulation phase value of each subcarrier. The predetermined mathematical operation adopts another operation formula ${E\left(1\right)}_k=R_k\&CenterDot;{(A{\left(1\right)}_k\&CenterDot;H_{\mathrm{est},k})}^{*}\&ap;{\left|H_k\right|}^2\&CenterDot;{\left|A_k\right|}^2{e}^{j\frac{2\mathrm{\&pi;sk}}{N_{\mathrm{FFT}}}}+N_k\&CenterDot;{A_k}^{*}{H_{\mathrm{est},k}}^{*},$ (formula 24)

Also the modulation phase value for each subcarrier.

Then E (t)_k，k＝0,1,....N_FFT-1 IFFT operation, each PFC symbol will result in t IFFT operation results, optionally taking the absolute value or square of the absolute value,then, according to a predetermined selection rule, the most reliable one of the T results of T is selected as the operation result of the PFC symbol, and the corresponding T value can solve the signaling transmitted by the different sequences in the frequency domain. The most reliable method of judgment in the predetermined selection rule may be peak maximization or peak-to-average maximization, etc.

If the known frequency domain sequence set of each PFC symbol has only 1 known sequence, the step of selecting the one with the largest peak-to-average ratio among the T results as the operation result of the symbol can be omitted, and the unique IFFT result of each symbol can be directly selected.

Fig. 13 is a waveform diagram of an inverse fourier result of a time-domain main signal under AWGN in the second embodiment of the present invention. The maximum discrete inverse fourier transform is shown to occur at 633 f, 0.9996 f.

Then, assuming that the PFC has Q time domain symbols, the following waveform c (Q) of the Q time domain symbols will be obtained, Q being 1. Note that c (q) may be the result of some original IFFT chosen from the T results, or may be the result of taking the absolute value or the square of the absolute value.

At this time, since the operation in the frequency domain includes removing the influence of the channel, the position of the peak with the largest absolute value in c (q) can be directly used to derive the time domain cyclic shift value, thereby deriving the signaling transmitted by the frequency domain modulation frequency offset, i.e. the time domain cyclic shift value, for example, the position corresponding to the largest peak in the above figure is 633. (the calculation method is not limited here.)

However, considering the influence of noise and multipath and the influence of interference paths under various reasons, it is further possible to perform noise filtering on the operation result of each symbol, i.e. the large value is retained and the small values are all set to zero, and this step is optional. The processing results corresponding to all PFC symbols are obtained, and are named as C' (Q), Q1.

Then, the C '(q) of the next symbol is circularly shifted, multiplied or conjugate multiplied with the C' (q-1) of the previous symbol and accumulated, and the one with the largest accumulated value is found out, and the transmitted signaling can be calculated by the corresponding shift value. After the transmission signaling meets the pre-generated subcarriers generated by the frequency domain sequence of the time domain main signal A corresponding to the PFC symbol in the preset transmission rule of the transmitting end, each effective subcarrier is subjected to phase modulation according to an S value, namely, the method is realized in a mode of performing cyclic shift on the time domain OFDM symbol after IFFT.

As described in more detail below, cyclic shifting of C '(q) by V yields C' (q, V), which can be either left-shifted or right-shifted, in this case right-shifted, V ∈ [0, N_FFT-1]，

Then, for example, the following conjugate multiplication accumulation operation is performed,

$\mathrm{Accum}\left(V\right)=\underset{i=0}{\overset{N_{\mathrm{FFT}}-1}{\mathrm{\&Sigma;}}}{C}^{\&prime;}(q-1)\&CenterDot;\mathrm{conj}\left(C^{\&prime;\&prime;}(q,V)\right)$ (equation 25)

It should be noted that the above is only an example, and is not limited to conjugate multiplication, and the multiplication and accumulation operations do not need to be N_FFTAnd (4) point counting, namely, only a few large-value points are required.

Finally, the largest Accum (V) in absolute value is selected, and the corresponding V value corresponds to the transmitted signaling.

Note that the channel estimation value H used in the above description_est,The first PFC symbol is usually known and is obtained by performing a time domain/frequency domain estimation method from a known sequence, for example, obtaining the received frequency domain signal in the frequency domain with the known frequency domain sequence. And channel estimation of subsequent symbols, after the decoding of the last symbol of the PFC is finished, assuming that the decoding is correct, the channel estimation is performed again in the time domain/frequency domain by using the decoded information of the last symbol as the transmission information, and a certain specific operation is performed with the previous channel estimation result to obtain a new channel estimation result for channel estimation of signaling analysis of the next symbol.

It is specifically noted that the IFFT operations mentioned in the first and second embodiments have specific mathematical relationships based on the IFFT operations and FFT operations, and if the IFFT operations are equivalently implemented by FFT, the IFFT operations do not depart from the content of the present invention.

The first embodiment and the second embodiment both adopt coherent demodulation, and the time domain eliminates noise, and have very robust performance under multipath channels and low signal-to-noise ratio. Compared with the method of directly differentiating the front symbol frequency domain and the rear symbol frequency domain in the background technology, the method avoids amplifying noise. And further, the relative displacement of the operation structure of the front symbol and the rear symbol is utilized, so that the problem of misjudgment when the channel estimation is not accurate or interference paths occur due to various reasons is solved.

Fig. 14 is a schematic flowchart illustrating signaling analysis in a preamble symbol receiving method according to a third embodiment of the present invention.

Fig. 14 is a schematic diagram illustrating a signaling analysis flow in a preamble symbol receiving method according to a third embodiment of the present invention, where the signaling analysis flow is included in the same preamble symbol receiving method as that in fig. 1 corresponding to the first embodiment, and an overall overview of the preamble symbol receiving method is omitted in the third embodiment, and fig. 14 is another embodiment of fig. 2 and 12.

As shown in fig. 14, in step S1-2, determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol, the signaling analyzing step includes the following specific steps:

step S2-3-1: expanding the known frequency domain signaling set of each time domain symbol into a known frequency domain signaling expansion set;

step S2-3-2: carrying out Fourier transform on the time domain main signal of each time domain symbol and extracting effective subcarriers;

step S2-3-3: carrying out predetermined mathematical operation on each effective subcarrier, a known subcarrier corresponding to each frequency domain known sequence in a known frequency domain signaling expansion set and a channel estimation value to obtain an operation value, and then accumulating the operation values on all effective subcarriers; and

step S2-3-4: selecting an accumulated value from the accumulated values according to a second preset selection rule, utilizing a frequency domain known sequence of a corresponding known frequency domain signaling extension set to obtain a frequency domain modulation frequency offset value, namely a time domain cyclic shift transmitted signaling, and obtaining a known frequency domain sequence in the corresponding known frequency domain signaling set before original extension to solve signaling information transmitted by different sequences in the frequency domain.

Specifically, the known frequency domain signaling set for each time domain symbol is first extended to a known frequency domain signaling extension set. And then carrying out FFT operation on the time domain main signal A corresponding to each PFC symbol to obtain a frequency domain signal, taking out the value of an effective subcarrier from the frequency domain signal, carrying out preset mathematical operation (conjugate multiplication/division operation) on the subcarrier corresponding to each frequency domain known sequence of each effective subcarrier and a known frequency domain signaling expansion set and a channel estimation value, and then accumulating the operation values on all the subcarriers to obtain an accumulated value. And finally, based on the multiple groups of accumulated values, selecting the most reliable one according to a second preset selection rule, and utilizing the frequency domain known sequence of the corresponding known frequency domain signaling extension set to obtain a modulation frequency offset value, thereby obtaining a frequency domain modulation frequency offset, namely a signaling transmitted by time domain cyclic shift, and simultaneously obtaining the corresponding known frequency domain sequence in the known frequency domain signaling set before the original extension, and solving the signaling transmitted by different frequency domain sequences.

When the symbol-unexpanded known frequency domain signaling set only has one known sequence, i.e. signaling transmitted only by means of frequency domain modulation frequency offset, i.e. time domain cyclic shift value, the third embodiment is simplified as follows:

the unique known frequency domain sequence for each symbol is first spread into a set of known frequency domain signaling spreads. And then carrying out FFT operation on the time domain main signal A corresponding to each PFC symbol to obtain a frequency domain signal, taking out the value of an effective subcarrier from the frequency domain signal, carrying out preset digital operation (conjugate multiplication/division operation) on the subcarrier corresponding to each frequency domain known sequence of each effective subcarrier and a known frequency domain signaling expansion set and a channel estimation value, and then accumulating the operation values on all the subcarriers to obtain an accumulated value. And finally, based on the multiple groups of accumulated values, selecting the most reliable one, and utilizing the frequency domain known sequence of the corresponding known frequency domain signaling extension set to obtain a modulation frequency offset value, so as to obtain the frequency domain modulation frequency offset, namely the signaling transmitted by time domain cyclic shift.

The known frequency domain signaling set herein refers to all possible sequences of the time domain main signal a corresponding to each PFC time domain symbol that are filled to the frequency domain sequence of the subcarrier before the modulation phase of the frequency domain subcarrier, such as a modulation PN operation at a transmitting end, and refers to all possible frequency domain sequences after the modulation PN.

The known frequency domain signaling extension set is obtained by: and correspondingly modulating the subcarrier phase according to all possible frequency offset values by each known frequency domain sequence in the known frequency domain signaling set, and generating S modulated frequency offset known sequences by all possible S modulated frequency offset values. For example, if there are T known frequency domain sequences L in the original known frequency domain signaling set₁，L₂…，L_TThen each known frequency domain sequence L_tRespectively obtaining L according to S modulation frequency offset values_t，1,L_t，2,…,L_t,SAnd the like. For example:

where k corresponds to the subcarrier number. Where the zero carrier is placed at sequence number 0. The number S of the modulation frequency offset values is multiplied by the number T of the known frequency domain sequences, so that the T known frequency domain sequences are expanded into T & S known frequency domain sequences to form a known frequency domain signaling expansion set.

When the symbol has only one known sequence in the un-extended known frequency domain signaling set, i.e. signaling transmitted only by means of frequency domain modulation frequency offset, i.e. time domain cyclic shift value, i.e. T ═ 1, then the extended set contains S known frequency domain sequences in total.

Specifically, for example, K is 0: N_zc-1,N_zcIs the number of effective sub-carriers, H_est,kFor the channel estimation value corresponding to the k-th effective sub-carrier, R_kFor the value of the k-th valid subcarrier received, L_k,t,sAnd taking the kth value of the t and s sequences in the known frequency domain sequence spreading set.

Then

$\begin{array}{ccc}{\mathrm{corr}}_{t,s}=\mathrm{Re}\left(\underset{k=0}{\overset{N_{\mathrm{ZC}}-1}{\mathrm{\&Sigma;}}}{R}_k{H_{\mathrm{est},k}}^{*}{L_{k,t,s}}^{*}\right)& t=0:T-1& s=0:S-1\end{array}$ (formula 26)

Or

$\begin{array}{ccc}{\mathrm{corr}}_{t,s}=\left|\left(\underset{k=0}{\overset{N_{\mathrm{ZC}}-1}{\mathrm{\&Sigma;}}}{R}_k{H_{\mathrm{est},k}}^{*}{L_{k,t,s}}^{*}\right)\right|& t=0:T-1& s=0:S-1\end{array}$ (formula 27)

Where | represents an absolute value operation.

Take max (corr)_t,s) Or the corresponding t and s can be used for obtaining a modulation frequency offset value by utilizing the frequency domain known sequence of the known frequency domain signaling extended set corresponding to s, so that the signaling transmitted by the frequency domain modulation frequency offset, namely the time domain cyclic shift is obtained; and meanwhile, a known frequency domain sequence in the corresponding original known frequency domain signaling set before expansion is obtained by utilizing t, and the signaling transmitted by different sequences of the frequency domain is solved.

When the symbol has only one known sequence in the un-extended known frequency domain signaling set, i.e. signaling transmitted only by means of frequency domain modulation frequency offset, i.e. time domain cyclic shift value, i.e. T ═ 1, then the extended set contains S known frequency domain sequences in total. And the modulation frequency offset value can be obtained by using the frequency domain known sequence of the known frequency domain signaling extension set corresponding to the signal sequence s, so that the signaling transmitted by the frequency domain modulation frequency offset, namely the time domain cyclic shift, is obtained.

Note that H is used in the above description_estThe first PFC symbol is usually known and can be obtained by performing a time domain/frequency domain estimation method using a known sequence, for example, after decoding of a previous symbol of the PFC is finished, assuming that the decoding is correct, using the previous decoded information as the transmission information, performing channel estimation again in the time domain/frequency domain, and performing a certain specific operation with the previous channel estimation result to obtain a new channel estimation result for channel estimation of signaling analysis of a next symbol.

Not shown in the figure, an embodiment of the present invention further provides a receiving apparatus for preamble symbols, where when the transmitting apparatus satisfies a predetermined transmission rule, the receiving apparatus includes: a processing judgment part for judging whether the baseband signal obtained by the processing has the preamble symbol; and a positioning analysis part for determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol.

Wherein, the positioning analysis part comprises: the carrier extraction unit is used for extracting effective subcarriers after carrying out Fourier transform on the time domain main body signal of each time domain symbol; the operation processing unit is used for performing inverse Fourier transform on each effective subcarrier and a known subcarrier corresponding to each frequency domain known sequence in a known frequency domain signaling set of the time domain symbol after predetermined mathematical operation, and obtaining an inverse Fourier result corresponding to each frequency domain known sequence; and each time domain symbol is based on a selected inverse Fourier result selected from one or more inverse Fourier results by a first preset selection rule, then a plurality of time domain symbols are subjected to preset processing operation, and signaling information is solved based on the obtained inter-symbol processing result.

Not shown in the figure, an embodiment of the present invention further provides a receiving apparatus for preamble symbols, where when the transmitting apparatus satisfies a predetermined transmission rule, the receiving apparatus includes: a processing judgment part for judging whether the baseband signal obtained by the processing has the preamble symbol; and the positioning analysis part is used for determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol.

Wherein, the positioning analysis part comprises: the carrier extraction unit is used for extracting effective subcarriers after carrying out Fourier transform on the time domain main body signal of each time domain symbol; the operation processing unit is used for performing inverse Fourier transform on the known subcarrier corresponding to each frequency domain known sequence in the known frequency domain signaling set of each effective subcarrier and the time domain symbol and the channel estimation value after performing predetermined mathematical operation, and obtaining an inverse Fourier result corresponding to each frequency domain known sequence; and a selected parsing unit, each time domain symbol being used for directly solving the signaling information and/or performing a predetermined processing operation between a plurality of time domain symbols based on a selected inverse fourier result selected from the one or more inverse fourier results by a first predetermined selection rule, and solving the signaling information based on the obtained inter-symbol processing result.

Not shown in the figure, an embodiment of the present invention further provides a receiving apparatus for preamble symbols, where when the transmitting apparatus satisfies a predetermined transmission rule, the receiving apparatus includes: a preamble symbol receiving apparatus adapted to be used when a transmitting apparatus satisfies a predetermined transmission rule, comprising: a processing judgment part for judging whether the baseband signal obtained by the processing has the preamble symbol; and the positioning analysis part is used for determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol.

Wherein, the positioning analysis part comprises: an extension unit for extending the known frequency domain signaling set of each time domain symbol into a known frequency domain signaling extension set; the carrier extraction unit is used for extracting effective subcarriers after carrying out Fourier transform on the time domain main body signal of each time domain symbol; the operation processing unit is used for carrying out preset mathematical operation on each effective subcarrier, a known subcarrier corresponding to each frequency domain known sequence in a known frequency domain signaling expansion set and a channel estimation value to obtain an operation value, and then accumulating the operation values on all the effective subcarriers; and the selected analysis unit selects an accumulated value from the groups of accumulated values according to a second preset selected rule, deduces a frequency domain modulation frequency offset value, namely a time domain cyclic shift transmitted signaling by using a frequency domain known sequence of a known frequency domain signaling expansion set corresponding to the accumulated value, deduces a known frequency domain sequence in the corresponding known frequency domain signaling set before original expansion, and solves signaling information transmitted by different frequency domain sequences.

The preamble symbol generating device and the receiving device provided in this embodiment may respectively correspond to the preamble symbol generating method and the receiving method in the foregoing embodiments, so that the structure and technical elements in the device may be formed by corresponding conversion of the generating method, and are not described again here.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications of the present invention without departing from the spirit and scope of the present invention by using the methods and technical contents disclosed above.

Claims (11)

1. A method for receiving a preamble symbol is suitable for a sending end to meet a preset sending rule, and is characterized by comprising the following steps:

judging whether a preamble symbol exists in the baseband signal obtained by processing;

determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol,

wherein the step of determining and analyzing comprises:

performing Fourier transform on the time domain main signal of each time domain symbol to extract effective subcarriers;

performing inverse Fourier transform on each effective subcarrier and a known subcarrier corresponding to each frequency domain known sequence in a known frequency domain signaling set of the time domain symbol after predetermined mathematical operation, and obtaining an inverse Fourier result corresponding to each frequency domain known sequence; and

each time domain symbol is based on a selected inverse fourier result selected from one or more of the inverse fourier results by a first predetermined selected rule, and then a predetermined processing operation is performed between the plurality of time domain symbols, and the signaling information is resolved based on the obtained inter-symbol processing result.

2. A method of receiving preamble symbols according to claim 1,

wherein the predetermined transmission rule is: and after the frequency domain main body sequence corresponding to the time domain main body signal in each sent time domain symbol is processed to obtain a generated pre-generated subcarrier, performing phase modulation or inverse Fourier transform on each effective subcarrier in a frequency domain by using a preset frequency offset value S, and performing cyclic shift in the time domain.

3. A preamble symbol receiving method as claimed in claim 1, further comprising,

and taking an absolute value or taking the square of the absolute value of the selected result of the inverse Fourier transform, and selecting the selected result of the inverse Fourier transform according to the first preset selection rule.

4. A method of receiving preamble symbols according to claim 1,

wherein the first predetermined selected rule comprises selecting at peak maximum and/or selecting at peak-to-average ratio maximum.

5. A preamble symbol receiving method as claimed in claim 1, further comprising,

a noise filtering processing step, comprising:

the inverse Fourier result of each time domain symbol can be subjected to noise filtering, a large value is reserved, and small values are all set to zero.

6. A method of receiving preamble symbols according to claim 1,

wherein, the analyzed signaling information includes: different frequency domain sequences transmit signaling and/or signaling transmitted by frequency domain modulation frequency offset, namely time domain cyclic shift value.

7. A method of receiving preamble symbols according to claim 1,

the known frequency domain signaling set refers to all possible sequences of a main time domain signal corresponding to each time domain symbol, which are filled to a frequency domain sequence of a subcarrier before a modulation phase of the frequency domain subcarrier.

8. A preamble symbol receiving method as claimed in claim 7,

wherein, when the known frequency domain sequence set of the time domain symbols only has 1 known sequence, the first predetermined selection rule is to directly take the unique inverse fourier result of each time domain symbol as the inverse fourier selection result, then perform predetermined processing operation among a plurality of time domain symbols, and solve the signaling information based on the obtained inter-symbol processing result.

9. A method of receiving preamble symbols according to claim 1,

wherein the predetermined mathematical operation comprises: conjugate multiplication or division.

10. A method of receiving preamble symbols according to claim 1,

wherein, the step of performing a predetermined processing operation between the plurality of time domain symbols and solving the signaling information based on the obtained inter-symbol processing result comprises:

and circularly shifting the next time domain symbol, multiplying or conjugatively multiplying the next time domain symbol by the previous time domain symbol, accumulating to obtain an accumulated value, finding out a shift value corresponding to the maximum accumulated value in all the preset frequency offset values or the cyclic shift values, and calculating the signaling information by using the shift value.

11. A preamble symbol receiving apparatus adapted to be used when a transmitting apparatus satisfies a predetermined transmission rule, comprising:

a processing judgment part for judging whether the baseband signal obtained by the processing has the preamble symbol; and

a positioning analysis part for determining the position of the preamble symbol in the physical frame and analyzing the signaling information carried by the preamble symbol,

wherein the positioning analysis unit includes:

the carrier extraction unit is used for extracting effective subcarriers after the time domain main body signal of each time domain symbol is subjected to Fourier transform;

the operation processing unit is used for performing inverse Fourier transform on each effective subcarrier and a known subcarrier corresponding to each frequency domain known sequence in a known frequency domain signaling set of the time domain symbol after predetermined mathematical operation, and obtaining an inverse Fourier result corresponding to each frequency domain known sequence; and

and each time domain symbol is based on a selected inverse Fourier result selected from one or more inverse Fourier results by a first preset selected rule, then a plurality of time domain symbols are subjected to preset processing operation, and the signaling information is solved based on the obtained inter-symbol processing result.