CN101374129A - Synchronization sequence generation method, synchronization method and system based on orthogonal frequency division multiplexing - Google Patents

Abstract

The present invention provides a synchronization method and system based on orthogonal frequency multiplexing and a synchronization sequence generation method, which are applied to a wireless communication system. The synchronization method includes the following steps: (a) the transmitter of the synchronization sequence generates a synchronization sequence in the time domain The initial sequence A is divided into k subsequences A _i , and then according to the selected derivation operation method, the subsequence B _i of sequence B is derived from each subsequence A _i correspondingly, 1≤i≤k; (b) The transmitting end combines the corresponding subsequences A _i and B _i into a subsequence pair S _i , combines the obtained k subsequence pairs to generate a synchronization sequence S, and then performs a Fourier transform operation to generate a corresponding frequency domain synchronization sequence, and then maps to the corresponding sub-carrier as a synchronous signal; (c) the receiving end parses the received synchronous signal according to the structure of the synchronous sequence generated, and obtains the subsequences A _i and _Bi of sequences A and B, according to the derived operation method The subsequence B _i is decomposed and operated to obtain each subsequence of the sequence A", and the correlation operation is performed on the sequences A and A" to complete the synchronization.

Description

Synchronization sequence generation method, synchronization method and system based on orthogonal frequency division multiplexing

technical field

The invention relates to a mobile communication system, in particular to a method for generating a time and frequency offset synchronization sequence based on an orthogonal frequency division multiplexing system, and a synchronization method and system based on the method for generating the synchronization sequence.

Background technique

With the development of digital signal processing technology and high-speed devices, Orthogonal Frequency Division Multiplexing (OFDM) technology has been successfully applied in communication systems. OFDM divides the spectrum into several orthogonal sub-channels in the frequency domain, and the carriers of each sub-channel overlap each other, which improves the spectrum utilization. Since the bandwidth of each sub-channel is relatively narrow, the frequency selective channel for the entire transmission bandwidth signal is flat fading for each sub-channel signal, and the equalization can be performed separately for each sub-carrier, which greatly simplifies the receiver structure . Because OFDM has the characteristics of high spectrum utilization rate and simple equalization, it is very suitable for high-speed communication, so it has been widely studied.

Compared with single-carrier systems, OFDM has its own disadvantages while having the above advantages: it is very sensitive to frequency offset. At the same time, the timing of the OFDM system must fall within the range allowed by the cyclic prefix (CP), otherwise, inter-symbol interference will be caused. Therefore, effective timing synchronization is very important for OFDM.

The performance indicators for investigating synchronization mainly include synchronization acquisition probability, synchronization time, receiver overhead, etc. At the same time, because the synchronization channel often needs to transmit some system parameter information, such as cell identification (ID) information, information necessary for broadcast channel (BCH) reception etc. Therefore, the complexity of the synchronization system is also a performance indicator to measure the quality of the synchronization scheme. In the current non-hierarchical synchronization structure design, there are mainly two synchronization methods. One is the synchronization method designed based on the cross-correlation scheme. This method transmits the generated synchronization sequence in the synchronization time slot and captures it by cross-correlation operation at the receiver. Although this method can obtain good capture performance, it is When there are many synchronization sequences, the receiver needs to match all the sequences at the same time, so the complexity is very large. Another solution is based on repetitive structure design. The sender constructs a repeated sequence format so that the receiver does not have to match all the sequences. Only need to perform autocorrelation operation on the received data to capture. The complexity is low, but in the OFDM system, due to the existence of CP (cyclic prefix), if autocorrelation capture is used, there will be a peak flattening phenomenon, which will affect the synchronization accuracy. However, if the cross-correlation method is used to capture, side peaks will appear, which will affect the search of adjacent cells.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for generating a synchronization sequence based on OFDM. The synchronization sequence generated by the method has low complexity and high synchronization accuracy during synchronization.

In order to solve the above technical problems, the present invention provides a synchronization method based on orthogonal frequency multiplexing, which is applied to a wireless communication system, and the method includes the following steps:

(a) The transmitting end of the synchronization sequence generates the initial sequence A in the time domain, and divides it into k subsequences A _i , and then derives the subsequence B of the sequence B from each subsequence A _i correspondingly according to the selected derivation operation method Sequence B _i , 1≤i≤k;

(b) The transmitting end combines the corresponding subsequences A _i and B _i into subsequence pairs S _i , combines the obtained k subsequence pairs to generate a synchronization sequence S in the time domain, and then generates the corresponding S through Fourier transform operation The frequency domain synchronization sequence is then mapped to the corresponding subcarrier and transmitted as a synchronization signal;

(c) The receiving end parses the received synchronization signal according to the structure of the generated synchronization sequence, and obtains the subsequences A _i and B i of sequences A and B, and calculates the subsequence _{B i according} to the derived operation method to obtain sequence A" Each sub-sequence of A and A" is correlated to complete the synchronization.

Further, the above method may also have the following features, step (b) before the sending end generates the synchronization sequence S, it also adjusts the order of the subsequences of A and B in the partial subsequence pair, so that in the synchronization sequence S, In two adjacent subsequence pairs, the two subsequences adjacent to each other are both subsequences of A or subsequences of B.

Further, the above method may also have the following features, step (b) before the sending end generates the synchronization sequence S, it also mirrors the data of a subsequence A _i or B _i in each subsequence pair S _i processing, get S _i as A _i B _i ′ or B _i ′A _i or A _i ′B _i or B _i A _i ′, where A _i ′ is the mirror image subsequence corresponding to A _i , and B _i ′ is corresponding to The mirrored subsequence of B _i ; step (c) when the receiving end parses the received synchronization signal, it needs to restore the mirrored subsequence to the subsequence before mirroring processing.

Further, the above method may also have the following characteristics, when k is an odd number, the generated synchronization sequence S is one of the following structures:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ;</span>$

When k is an even number, the generated synchronization sequence S is one of the following structures:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}$

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; .</span>$

Further, the above method may also have the following characteristics, the operation method selected in step (b) is to obtain B _i by taking the conjugate of A _i .

Further, the above-mentioned method can also have the following characteristics, when the step (c) performs a correlation operation on the sequences A and A", first perform a correlation operation on the subsequences corresponding to A and A", respectively, to obtain the correlation values of each pair of subsequences, Then the correlation value of each pair of sub-sequences is added as the correlation value of the whole sequence to complete the synchronization.

Further, the above method can also have the following characteristics, the time domain length of the initial sequence A generated in step (a) is N/2, N is the bandwidth of the synchronization channel, and when dividing A, it is divided into It is equally divided into k subsequences A _i .

A method for generating a synchronization sequence based on orthogonal frequency multiplexing, comprising the steps of:

(a) The transmitter of the synchronization sequence generates the initial sequence A in the time domain, and divides it into k subsequences A _i , 1≤i≤k;

(b) The transmitting end derives the subsequence B _i of the sequence B from each subsequence A _i respectively according to the selected operation method;

(c) The transmitting end combines the corresponding subsequences A _i and B _i into a subsequence pair S _i , and combines the obtained k subsequence pairs to generate a synchronization sequence S in the time domain.

Further, the above-mentioned method may also have the following characteristics, step (c) also adjusts the order of the subsequences of A and B in the partial subsequence pair before generating the synchronization sequence in the time domain, so that in the generated synchronization sequence, two In the pair of adjacent subsequences, the two subsequences adjacent to each other are both subsequences of A or subsequences of B.

Further, the above method may also have the following characteristics, before generating the synchronization sequence in the time domain, the data of each subsequence A _i or B _i in S _i is mirrored, that is, Said S _i is A _i B _i ′ or B _i ′A _i or A _i ′B _i or B _i A _i ′, wherein A _i ′ _is the mirror image subsequence corresponding to A i , and B _i ′ is the subsequence corresponding to B _i The mirror subsequence of .

Further, the above-mentioned method can also have the following characteristics, after the step (c), it also includes a step (d): perform a Fourier transform operation on the synchronization sequence S according to its corresponding inverse Fourier transform IFFT points, and generate a corresponding frequency domain synchronization sequence .

Further, the above method can also have the following characteristics, in step (c),

When k is an odd number, the generated synchronization sequence S is one of the following structures:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ;</span>$

When k is an even number, the generated synchronization sequence S is one of the following structures:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}$

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; .</span>$

Further, the above method can also have the following characteristics, the time domain length of the initial sequence A generated in step (a) is N/2, N is the bandwidth of the synchronization channel, and when dividing A, it is divided into It is equally divided into k subsequences A _i .

Further, the above method may also have the following characteristics, the operation method selected in step (b) is to obtain B _i by taking the conjugate of A _i .

An OFDM system, comprising a transmitting end, the transmitting end further comprises an initial sequence generation unit, a derivation unit, a combining unit, and a transmitting unit, wherein,

The initial sequence generation unit is used to generate the initial sequence A in the time domain, and divide it into k subsequences A _i ;

The derivation unit is used to derive the subsequence B _i of the sequence B correspondingly from each subsequence A _i according to the selected derivation operation mode, 1≤i≤k;

The combination unit is used to combine subsequences A _i and B _i into subsequence pairs S _i , and combine the obtained k subsequence pairs to generate a synchronization sequence S in the time domain;

The transmitting unit is used to generate a synchronization sequence in the corresponding frequency domain through the Fourier transform operation of the synchronization sequence S, and then map it to a corresponding subcarrier and transmit it as a synchronization signal;

It also includes a receiving end, and the receiving end further includes a receiving analysis unit and a related computing unit, wherein,

The receiving analysis unit is used to receive the synchronization signal, analyze the received synchronization signal according to the structure of the generated synchronization sequence, and obtain the subsequences A _i and B _i of the sequences A and B, according to the derivative operation mode of the derivation unit Solve the operation on the subsequence B _i to obtain each subsequence of the sequence A";

The correlation calculation unit is used to perform correlation calculations on sequences A and A" to complete synchronization.

Further, the above-mentioned system can also have the following characteristics, when the combination unit generates the synchronization sequence S, it also adjusts the order of the subsequences of A and B in the partial subsequence pair, so that in the synchronization sequence S, two phases In the pair of adjacent subsequences, the two subsequences adjacent to each other are both subsequences of A or subsequences of B.

Further, the above-mentioned system can also have the following characteristics, when the combination unit generates the synchronization sequence S, it also mirrors the data of a subsequence A _i or B _i in each subsequence pair S _i to obtain S _i is A _i B _i ′ or B _{i ′} A _i or A _i ′B _i or B _i A _i ′, where A _i ′ is the mirror image subsequence corresponding to A i , and B _i ′ is the subsequence corresponding to B _i mirror subsequence;

When the receiving analysis unit at the receiving end analyzes the received synchronization signal, it needs to restore the mirrored subsequence to the subsequence before mirroring processing.

Further, the above system can also have the following characteristics, when k is an odd number, the synchronization sequence S obtained by the combination unit is one of the following structures:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ;</span>$

When k is an even number, the generated synchronization sequence S is one of the following structures:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}$

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; .</span>$

Further, the above system may also have the following feature, the derivation unit obtains B _i by taking the conjugate of A _i .

Further, the above-mentioned system can also have the following characteristics. When the correlation operation unit performs correlation operations on sequences A and A", it first performs correlation operations on the subsequences corresponding to A and A" to obtain the correlation values of each pair of subsequences , and then add the correlation values of each pair of sub-sequences as the correlation value of the whole sequence to complete the synchronization.

Further, the above system may also have the following characteristics, the time domain length of the initial sequence A generated by the initial sequence generation unit is N/2, N is the bandwidth of the synchronization channel, and when A is divided, it is Divide it equally into k subsequences A _i .

This paper proposes a design scheme that combines synchronization and diversity into consideration. This scheme can reduce the complexity of synchronization while ensuring synchronization performance, and at the same time avoid side peaks during cross-correlation.

Description of drawings

FIG. 1 is a flow chart of a transmitter constructing and transmitting a synchronization sequence according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a time-domain sequence structure according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a data format of a time domain sequence according to an embodiment of the present invention.

FIG. 4 is a basic flow chart of receiving end synchronization according to an embodiment of the present invention.

Detailed ways

Aiming at the problems existing in the current synchronization structure design, the present invention designs a segmented and interleaved synchronization structure. In this synchronization structure, the receiver can overcome the problem of excessively high complexity of cross-correlation capture by performing autocorrelation operations, and at the same time can Improve the capture performance of autocorrelation, as well as the synchronization problem in high-speed scenes, and overcome the peak flat top and side peak problems of autocorrelation capture.

Assuming that the number of useful subcarriers of the synchronization channel is N, the number of segments is determined to be k according to the high-speed evaluation of the system. The sending end of the synchronization sequence constructs and sends the method for the synchronization sequence as shown in Figure 1, including the following steps:

Step 110: determine the time domain length of the synchronization sequence, and generate an initial sequence A in the time domain (in order to be separated from the final synchronization sequence, A is called the initial sequence, and S is called the synchronization sequence, please approve);

According to the synchronization channel bandwidth, determine the time domain length of the initial sequence A. When the bandwidth length is N, its A length is selected as N/2, where the A sequence is all optional synchronization sequences. For example: ZC, GCL sequence, etc.

Step 120: Divide A into k segments to generate k subsequences A _i , 1≤i≤k;

The segment number k may be determined according to the maximum moving speed of the user equipment UE considered by the system. The k here can be determined by simulation to obtain the most suitable k. For segment A, it can also be divided equally or not. But it is certain that the specific segmentation situation is known at the receiving end.

Step 130: Select an operation method for deriving sequence B from initial sequence A, and derive subsequence B _i of B from each subsequence A _i of A;

When selecting the operation method, there should be a good correlation between each subsequence of A and each subsequence of B (not the correlation between B _i and A _i , right?), and at the same time make the relationship between each subsequence of B There is a good correlation. The correlation thresholds are at least lower than the respective conjugate correlations. For example, the operation method can be obtained by conjugating the subsequence of A to obtain B, and B can also be obtained symmetrically according to different zero-crossing points, that is, the correspondence between each A and B subsequences is independent of each other, for example: for different A _i and its derived B _i are calculated in different ways.

Step 140: combining A _i and B _i to obtain a subsequence pair S _i , and mirroring the data of the subsequence A _i or B _i in S _i to generate a mirror image subsequence of A _i or B _i ;

The specific method is as follows, assuming that A _i is a _i1 a _i2 ...... a _in , and the derived B _i is b _i1 b _i2 ...... _bin , then the combined S _i can be a _i1 a _i2 ......a _in b _in b _i(n-1) ......b _i2 b _i1 , or b _in b _i(n-1) ......b _i2 b _i1 a _i1 a _i2 ......a _in , or b _i1 b _i2 .....b _i(n-1) b _in a _in a _i(n-1) .....a _i2 a _i1 , or a _in a _i(n-1) ..... a _i2 a _i1 b _i1 b _i2 ..... b _i(n-1) b _in .

Denote the mirror image sequence of A _i as A _i ′, A _i ′ is a _in a _i(n-1) ...... a _i1 a _i2 , and denote the mirror image sequence of B _i as B _i ′, B _i ’ is b _in b _i(n-1) ...... b _i2 b _i1 , then S _i can be A _i B _i ′, or B _i ′A _i , or B _i A _i ′, or A _i 'B _i .

Step 150: Combining the above subsequence pairs in sequence into a synchronous sequence S=S ₁ S ₂ .... S _k , and adjusting the order of the subsequences of A and B in some subsequence pairs so that two adjacent subsequence pairs The two subsequences adjacent to each other are either subsequences of A or subsequences of B;

In this paper, the mirror image sequence A _i ′ of A _i and A _i is regarded as a subsequence of A, and the mirror image sequence B _{i ′} of B i and _{B i} is regarded as a subsequence of B. After order adjustment, S _i S _i+1 can be A _i B _i ′B _i+1 ′A _i+1 , or A _i B _i ′B _i+1 A _i+1 ′, or B _i ′A _i A _i+1 ′B _i+1 , or B _i ′A _i A _i+1 B _i+1 ′, and the rest are similar.

According to the above various combinations, when k is an odd number, the synchronous sequence S generated is one of the following structures:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ;</span>$

When k is an even number, the generated synchronization sequence S is one of the following structures:

${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}$

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="A"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">A</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="B"\; filenames="A200710141467E00192.png"\; state="\{\{state\}\}">B</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; .</span>$

The above-mentioned steps 140 and 150 can also be reversed in order. First, A _i and B _i are combined into S _i , and the synchronization sequence S ₁ S ₂ .... S _k is obtained from _{S i and} satisfies _{the and} The two adjacent subsequences of the opposite party are both subsequences of A or subsequences of B, and then perform mirroring processing on a subsequence A _i or B _i in S _i one by one, and the structure of the obtained synchronization sequence S is the same of.

So far, the construction of the entire time domain sequence is basically completed, as shown in Figure 2 and Figure 3 . When it is necessary to construct a synchronization sequence from the frequency domain, the following steps are performed:

In the synchronous sequence, the order of S ₁ S ₂ .... S _k can be rearranged, such as starting from the middle or the end in a cyclic shift manner, or disrupting the original order, and so on. However, after its reordering, its own relevance should be considered.

Step 160: Perform a Fourier transform (FFT) operation on the complete sequence generated in the time domain according to its corresponding inverse Fourier transform IFFT points, so as to generate a synchronization sequence corresponding to the frequency domain.

Step 170: Map the frequency-domain synchronization sequence generated above to its corresponding subcarrier for transmission. At this point, the construction of the synchronization channel is completely completed.

The calculation method and the selected structure of the above-mentioned synchronization sequence are known at the receiving end, and when performing synchronization processing, as shown in Figure 4, the following steps are included:

Step 410: Analyze the received synchronization signal according to the structure of the synchronization sequence to obtain the subsequences A _i and B _i that make up the synchronization sequence, including the process of restoring the mirror image subsequences to the original subsequences;

Step 420, according to the operation method of deriving the sequence B at the transmitting end to obtain the sequence B, perform the solution operation on the subsequence B _i respectively, and obtain the subsequence of the sequence A" which is structurally completely corresponding to the subsequence of A;

Since the signals appear in pairs in the time domain, the receiving end can solve the B _i according to the operation method specified by the system.

Step 430, performing a correlation operation on sequence A and sequence A" to complete synchronization.

In this step, when the correlation operation is performed on A and A", the correlation operation is first performed on the subsequences corresponding to A and A" to obtain the correlation value of each pair of subsequences, and the correlation values of each subsequence are added together as the correlation of the entire sequence value, the peak value can be accurately captured.

The present invention also proposes an OFDM system, which includes a transmitting end, and the transmitting end further includes an initial sequence generation unit, a derivation unit, a combining unit, and a transmitting unit, wherein,

The initial sequence generation unit is used to generate the initial sequence A in the time domain, and divide it into k subsequences A _i ;

The time domain length of the initial sequence A generated by the initial sequence generation unit is N/2, and N is the bandwidth of the synchronization channel, and when dividing A, it is equally divided into k subsequences A _i .

The derivation unit is used to derive the subsequence B _i of the sequence B correspondingly from each subsequence A _i according to the selected derivation operation mode, 1≤i≤k;

The derivation unit can conjugate a subsequence through A to obtain B.

The combination unit is used to combine subsequences A _i and B _i into subsequence pairs S _i , and combine the obtained k subsequence pairs to generate a synchronization sequence S in the time domain;

When generating the synchronization sequence S, the combination unit also adjusts the order of the subsequences of A and B in some subsequence pairs, so that in the synchronization sequence S, two adjacent subsequence pairs adjacent to each other All subsequences are subsequences of A or subsequences of B.

When the combination unit generates the synchronization sequence S, it also mirrors the data of a subsequence A _i or B _i in each subsequence pair S _i to obtain S _i as A _i B _i ' or B _i ′A _i or A _i ′B _i or B _i A _i ′, where A _i ′ is the mirror image subsequence corresponding to A _i , and B _i ′ is the mirror image subsequence corresponding to B _i .

The transmitting unit is used to generate a synchronization sequence in the corresponding frequency domain through the Fourier transform operation of the synchronization sequence S, and then map it to a corresponding subcarrier and transmit it as a synchronization signal;

It also includes a receiving end, and the receiving end further includes a receiving analysis unit and a related computing unit, wherein,

The receiving analysis unit is used to receive the synchronization signal, analyze the received synchronization signal according to the structure of the generated synchronization sequence, and obtain the subsequences A _i and B _i of the sequences A and B, according to the derivative operation mode of the derivation unit Solve the operation on the subsequence B _i to obtain each subsequence of the sequence A";

When the receiving analysis unit at the receiving end analyzes the received synchronization signal, it needs to restore the mirrored subsequence to the subsequence before mirroring processing.

The correlation calculation unit is used to perform correlation calculations on sequences A and A" to complete synchronization.

When the correlation calculation unit performs a correlation operation on A and A", it first performs a correlation operation on the subsequences corresponding to A and A" to obtain the correlation values of each pair of subsequences, and add the correlation values of each subsequence as the whole The correlation value of the sequence can accurately capture the peak value.

The inventive method has the following technical effects:

1) Compared with the existing time domain repetition structure, the synchronous sequence of the present invention adopts the combination of sequence A and B and the segmented structure, and makes the correlation value between each subsequence of A close to 0, thereby solving the cross-correlation operation side peak problem in .

2) The synchronization sequence of the present invention has a structure divided into k segments, which can greatly improve the synchronization performance under high-speed conditions.

Because under high-speed conditions, channel changes are relatively large. When the synchronization method of the present invention is at the receiving end, because of the use of autocorrelation, the two subsequences before and after it are relatively close, and _Ai and _Bi perform correlation operations, and the channel change is relatively small during this period. , so the peak value can be captured better, and the synchronization can be solved better. However, there is no segmentation in the prior synchronous sequence structure, and the ability to capture the peak value is poor.

3) Compared with the combination of the existing time domain A and B, it can solve the problem of flattening the correlation peak.

This problem is mainly solved by the present invention for subsequences that are the same sequence between each adjacent S subsequence, that is, either both are A or both are B. The method that the A and B subsequences are adjacent is for the nearest correlation to meet the synchronization under high-speed conditions. When the capture position dislocation is not a complete S subsequence, for example, when a subsequence of A is just wrong, if the sorting method of A1B1A2B2... is adopted, the correlation is B1A2B2 A3..., and its autocorrelation may produce certain Peak. But if it is the structure of A1B1B2A2... described in the present invention, the above problems can be solved. Because the correlation between the same complete sequence is very good. For example, both are subsequences of A, or both are subsequences of B.

4) When there is a relatively large frequency offset or time-selective fading in the channel, since the synchronization sequence of the present invention adopts a segmented structure and the A and B segments are separated, the channel characteristic change of adjacent signals is very small, then in Greater gains can be obtained in terms of anti-time fading and frequency offset.

5) Considering the complexity of the receiver, during the cell search process, due to the large number of cell IDs and the need to transmit the necessary information for BCH reception during the synchronization process, the amount of synchronization sequences is very large. If cross-correlation is used If the synchronous acquisition is carried out in the same way, the complexity of the receiver is very high. However, the complexity of synchronous capture in this scheme is equivalent to the complexity of using a repeating structure. Therefore, overheads such as synchronization time and computational complexity at the receiving end are reduced.

Claims (21)

1. A synchronization method based on Orthogonal Frequency Multiplexing, applied to a wireless communication system, the method comprises the steps: (a) The transmitting end of the synchronization sequence generates the initial sequence A in the time domain, and divides it into k subsequences A _i , and then derives the subsequence B of the sequence B from each subsequence A _i correspondingly according to the selected derivation operation method Sequence B _i , 1≤i≤k; (b) The transmitting end combines the corresponding subsequences A _i and B _i into subsequence pairs S _i , combines the obtained k subsequence pairs to generate a synchronization sequence S in the time domain, and then generates the corresponding S through Fourier transform operation The frequency domain synchronization sequence is then mapped to the corresponding subcarrier and transmitted as a synchronization signal; (c) The receiving end parses the received synchronization signal according to the structure of the generated synchronization sequence, and obtains the subsequences A _i and B i of sequences A and B, and calculates the subsequence _{B i according} to the derived operation method to obtain sequence A" Each sub-sequence of A and A" is correlated to complete the synchronization. 2. The method of claim 1, wherein: Step (b) Before the sending end generates the synchronization sequence S, it also adjusts the order of the subsequences of A and B in some subsequence pairs, so that in the synchronization sequence S, two adjacent subsequence pairs are opposite to each other Two adjacent subsequences are both subsequences of A or both are subsequences of B. 3. The method according to claim 1 or 2, characterized in that: Step (b) Before the sending end generates the synchronization sequence S, it also mirrors the data of a subsequence A _i or B _i in S _i for each subsequence, and obtains S _i as A _i B _i ' Or B _i ′A _i or A _i ′B _i or B _i A _i ′, wherein A _i ′ is a mirror image subsequence corresponding to A i, and B _i ′ is a mirror image subsequence corresponding to _{B i ;} Step (c) When the receiving end parses the received synchronization signal, it needs to restore the mirrored subsequence to the subsequence before mirroring processing. 4. The method of claim 3, wherein: When k is an odd number, the generated synchronization sequence S is one of the following structures: ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ;</span>$ When k is an even number, the generated synchronization sequence S is one of the following structures: ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; .</span>$ 5. The method according to claim 1 or 2, characterized in that: The operation mode selected in step (b) is to obtain B _i by taking the conjugate of A _i . (Please verify whether this statement is correct? In addition, is it a kind of conjugation to take symmetry according to different zero-crossing straight lines?) 6. The method of claim 1, 2 or 4, characterized in that: Step (c) When performing correlation operations on sequences A and A", first perform correlation operations on the subsequences corresponding to A and A" to obtain the correlation values of each pair of subsequences, and then add the correlation values of each pair of subsequences Synchronization is done as the relative value of the entire sequence. 7. The method of claim 1, 2 or 4, characterized in that: The time domain length of the initial sequence A generated in step (a) is N/2, and N is the bandwidth of the synchronization channel, and when dividing A, it is equally divided into k subsequences A _i . 8. A method for generating a synchronization sequence based on orthogonal frequency multiplexing, comprising the steps of: (a) The transmitter of the synchronization sequence generates the initial sequence A in the time domain, and divides it into k subsequences A _i , 1≤i≤k; (b) The transmitting end derives the subsequence B _i of the sequence B from each subsequence A _i respectively according to the selected operation method; (c) The transmitting end combines the corresponding subsequences A _i and B _i into a subsequence pair S _i , and combines the obtained k subsequence pairs to generate a synchronization sequence S in the time domain. 9. The method of claim 8, wherein: Step (c) Before generating the synchronization sequence in the time domain, the order of the subsequences of A and B in some subsequence pairs is also adjusted, so that in the generated synchronization sequence, two adjacent subsequence pairs adjacent to each other Both subsequences are subsequences of A or both are subsequences of B. 10. The method according to claim 8 or 9, characterized in that: Before generating the synchronization sequence in the time domain, each subsequence is also mirrored to the data of a subsequence A _i or B _i in S _i , that is, the S _i is A _i B _i ' or B _i ′A _i or A _i ′B _i or B _i A _i ′, where A _i ′ is the mirror image subsequence corresponding to A _i , and B _i ′ is the mirror image subsequence corresponding to B _i . 11. The method according to claim 8 or 9, characterized in that: After the step (c), a step (d) is also included: performing Fourier transform operation on the synchronization sequence S according to its corresponding inverse Fourier transform IFFT points to generate a corresponding frequency domain synchronization sequence. 12. The method according to claim 11, characterized in that: in step (c), When k is an odd number, the generated synchronization sequence S is one of the following structures: ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ;</span>$ When k is an even number, the generated synchronization sequence S is one of the following structures: ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; .</span>$ 13. The method of claim 8, 9 or 12, wherein: The time domain length of the initial sequence A generated in step (a) is N/2, and N is the bandwidth of the synchronization channel, and when dividing A, it is equally divided into k subsequences A _i . 14. The method of claim 8, 9 or 12, wherein: The operation method selected in step (b) is to obtain B _i by taking the conjugate of A _i . 15. An OFDM system, comprising a transmitting end, the transmitting end further comprising an initial sequence generation unit, a derivation unit, a combining unit, and a transmitting unit, wherein, The initial sequence generation unit is used to generate the initial sequence A in the time domain, and divide it into k subsequences A _i ; The derivation unit is used to derive the subsequence B _i of the sequence B correspondingly from each subsequence A _i according to the selected derivation operation mode, 1≤i≤k; The combination unit is used to combine subsequences A _i and B _i into subsequence pairs S _i , and combine the obtained k subsequence pairs to generate a synchronization sequence S in the time domain; The transmitting unit is used to generate a synchronization sequence in the corresponding frequency domain through the Fourier transform operation of the synchronization sequence S, and then map it to a corresponding subcarrier and transmit it as a synchronization signal; It also includes a receiving end, and the receiving end further includes a receiving analysis unit and a related computing unit, wherein, The receiving analysis unit is used to receive the synchronization signal, analyze the received synchronization signal according to the structure of the generated synchronization sequence, and obtain the subsequences A _i and B _i of the sequences A and B, according to the derivative operation mode of the derivation unit Solve the operation on the subsequence B _i to obtain each subsequence of the sequence A"; The correlation calculation unit is used to perform correlation calculations on sequences A and A" to complete synchronization. 16. The system of claim 15, wherein: When generating the synchronization sequence S, the combining unit also adjusts the order of subsequences of A and B in some subsequence pairs, so that in the synchronization sequence S, two adjacent subsequence pairs adjacent to each other All subsequences are subsequences of A or subsequences of B. 17. The system of claim 15 or 16, wherein: When the combination unit generates the synchronization sequence S, it also mirrors the data of a subsequence A _i or B _i in each subsequence pair S _i to obtain S _i as A _i B _i ' or B _i ′A _i or A _i ′B _i or B _i A _i ′, wherein A _i ′ is a mirror image subsequence corresponding to A _i , and B _i ′ is a mirror image subsequence corresponding to B _i ; When the receiving analysis unit at the receiving end analyzes the received synchronization signal, it needs to restore the mirrored subsequence to the subsequence before mirroring processing. 18. The system of claim 17, wherein: When k is an odd number, the synchronization sequence S obtained by the combination unit is one of the following structures: ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ;</span>$ When k is an even number, the generated synchronization sequence S is one of the following structures: ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; ,</span>$ ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&prime;</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&prime;</span>}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; .</span>$ 19. The system of claim 15 or 16, wherein: The derivation unit obtains B _i by taking the conjugate of A _i . 20. The system of claim 15, 16 or 18, wherein: When the correlation calculation unit performs correlation calculations on the sequences A and A", it first performs correlation calculations on the subsequences corresponding to A and A", respectively, to obtain the correlation values of each pair of subsequences, and then compare the correlation values of each pair of subsequences Added as the correlation value of the entire sequence to complete the synchronization. 21. The system of claim 15, 16 or 18, wherein: The time domain length of the initial sequence A generated by the initial sequence generation unit is N/2, and N is the bandwidth of the synchronization channel, and when dividing A, it is equally divided into k subsequences A _i .

Images