CN102045292B

CN102045292B - Synchronous sequence construction method for cooperative relay system

Info

Publication number: CN102045292B
Application number: CN 201010589162
Authority: CN
Inventors: 蒋雁翔; 尤肖虎; 高西奇
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2010-12-15
Filing date: 2010-12-15
Publication date: 2013-01-09
Anticipated expiration: 2030-12-15
Also published as: CN102045292A

Abstract

The invention discloses a synchronous sequence construction method for a cooperative relay system and relates to a design method for constructing a synchronous training sequence by utilizing constant amplitude zero autocorrelation base sequences and suitable for the cooperative relay system. The constructed synchronous sequence consists of two parts, wherein the first part consists of unequal period short base sequences; and the second part consists of long base sequences. Timing offset estimation can be finished according to the unequal period short base sequences in the constructed synchronous sequence; frequency offset estimation can be finished according to the long base sequences in the constructed synchronous sequence; and a related timing offset estimation algorithm only needs simple autocorrelation and crosscorrelation operation. By the synchronous sequence construction method provided by the invention, the problems of multi-timing offset and multi-frequency offset peculiar to the cooperative relay system are effectively solved; and a sequence-based synchronous algorithm is low in computational complexity and is high in estimated performance.

Description

Synchronous sequence construction method for cooperative relay system

Technical field

The present invention is a kind of synchronous sequence construction method that can be applicable in the cooperative relaying communication system, belongs to the simultaneous techniques field in the mobile communication.

Background technology

The basic problem that traditional cellular communication system faces is that the limited communication reliability that causes with timely change multipath fading of capacity that is caused by finite bandwidth descends.If continue to take this network configuration, can't adapt to the requirement of following wireless application.Relaying technique is by placing the relatively simply fixing or mobile-relay station of some functions and amplify or decipher the signal between repeating base station and the mobile subscriber in cellular cell, can reduce the transmitting power of signal, extend the coverage of base station, eliminate coverage hole, thereby can effectively reduce cost.Further, the cooperative relaying technology can be utilized space diversity further to resist the multipath fading of wireless channel, overcome shadow effect, thereby further strengthen communication quality by the cooperation between the relaying, improves spectrum efficiency.

Yet, in cooperative relay system, not because not mating mutually between different and a plurality of crystal oscillators of relaying location distribution, have a plurality of different timing slips and a plurality of different carrier frequency shifts between a plurality of repeated links, this is the most remarkable part that cooperative relay system is different from traditional Point-to-Point Communication System.Therefore, need research for the effective synchronous sequence construction method of cooperative relay system.

Summary of the invention

Technical problem: the objective of the invention is in collaboration relay system, a kind of synchronous sequence construction method that can effectively estimate a plurality of timing slips and a plurality of frequency shift (FS)s is provided.The synchronizing sequence that constructs has and generates simple, the low advantage of system load, and has lower computation complexity based on timing estimation and the frequency deviation estimating method of institute's tectonic sequence, but the while can reach gratifying systematic function requirement.

Technical scheme: the present invention is based on the communication for coordination relay system and puts forward for the existing a plurality of timing slips of this system and a plurality of this problem of frequency shift (FS).The synchronizing sequence that is suitable for collaboration relay system that utilizes the permanent width of cloth zero autocorrelation sequence to construct, whole sequence is made of two parts, finish respectively thick timing estimation,

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Thin timing estimation and decimal frequency bias are estimated, integer frequency bias is estimated; The first of sequence is by waiting short basic sequence of cycle to consist of, and wherein, it is different not to wait the cycle mainly to refer to its cycle of the basic sequence of weak point of corresponding each cooperative relaying, and the second portion of sequence waits long basic sequences of cycles to consist of by two; Short basic sequence adopts the permanent width of cloth zero autocorrelation sequence and takes full advantage of its good auto-correlation with cross correlation properties to overcome owing to partially partially affect the relay well interference that is brought with multifrequency when many; The frequency domain sequence corresponding with long basic sequence also adopts the permanent width of cloth zero autocorrelation sequence and takes full advantage of its good auto-correlation with cross correlation properties to optimize simultaneously decimal frequency bias and estimate and the performance of integer frequency bias estimation.

Its sequence structure concrete grammar is as follows:

1.) K cycle of structure is respectively L ₁, L ₂, L L _KDo not wait short basic sequence of cycle, and make it satisfy the permanent width of cloth zero automatic correlative property, wherein, K is the number of via node in the collaboration relay system;

2.) cycle repeats the basic sequence of above-mentioned weak point respectively, forms K the first corresponding to each relay synchronization sequence that length is N, and wherein, N is the data frame length of relay system, and its data are taken as 2 power, and can be decomposed into N=PQ and P, Q are arranged all be integer;

3.) structure length is the permanent width of cloth zero autocorrelation sequence of P, wherein, and P＜N and P=N/Q is arranged;

4. the sequence that) step 3 is constructed is done even zero insertion operation, is extended to the sequence that length is N=PQ;

5. the sequence that) step 4 is constructed is done respectively K ring shift right bit manipulation, and the displacement side-play amount is respectively 0, m, 2m, and L, (K-1) m, wherein,

Be basic displacement length,

For rounding operator;

6. K the sequence that) step 5 is constructed done respectively anti-Discrete Fourier transform operation, and the cycle repeat once, obtain K length and be the second portion corresponding to the synchronizing sequence of each relaying of 2N;

7.) insert zero prefix in the front of the first of the synchronizing sequence of constructing, between the first of the synchronizing sequence of constructing and second portion, insert Cyclic Prefix, then obtain the final synchronizing sequence corresponding to K relaying.

Beneficial effect:

1, in cooperation relay communication system, sequence constructing method proposed by the invention is simple, and the low complex degree that is beneficial to transmitter is realized;

2, based on sequence constructing method proposed by the invention, the timing estimation in the receiver and frequency deviation algorithm for estimating only need to be done simple auto-correlation and computing cross-correlation just can obtain good estimated performance, and the low complex degree that is beneficial to receiver is realized;

3, sequence constructing method proposed by the invention can extend in other communication systems such as distributing antenna system, wireless sensor network, self-organization network.

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Description of drawings

Fig. 1 is the cooperative relay system model framework chart.

Fig. 2 is synchronizing sequence overall structure schematic diagram.

Fig. 3 is the structural representation of the short-and-medium basic sequence of synchronizing sequence (SBS) part.

Fig. 4 is the frequency domain sequence structural representation corresponding to long basic sequence (LBS) part in the synchronizing sequence.

Fig. 5 is the implementation structure schematic diagram of the synchronous sequence construction method for cooperative relay system that proposes.

Embodiment

According to the implementation structure schematic diagram of synchronizing sequence overall structure schematic diagram shown in Figure 2 and synchronous sequence construction method for cooperative relay system shown in Figure 5, the specific implementation step that provides the synchronizing sequence that proposes is as follows:

A) structure K does not wait the cycle (cycle is respectively L ₁, L ₂, L L _K) the basic sequence of weak point, and make it satisfy the permanent width of cloth zero automatic correlative property;

B) cycle repeats the basic sequence of above-mentioned weak point respectively, forms K the first corresponding to each relay synchronization sequence that length is N;

C) structure length is the permanent width of cloth zero autocorrelation sequence of P;

D) sequence that step 3 is constructed is done even zero insertion operation, is extended to the sequence that length is N=PQ;

E) sequence that step 4 is constructed do respectively K ring shift right bit manipulation (displacement side-play amount be respectively 0, m, 2m, L, (K-1) m, wherein,

For rounding operator);

F) K the sequence that step 5 is constructed done respectively anti-Discrete Fourier transform operation, and the cycle repeat once, obtain K length and be the second portion corresponding to the synchronizing sequence of each relaying of 2N;

G) insert zero prefix in the front of the first of the synchronizing sequence of constructing, between the first of the synchronizing sequence of constructing and second portion, insert Cyclic Prefix, then obtain the final synchronizing sequence corresponding to K relaying.

Claims

1. synchronous sequence construction method for cooperative relay system, the synchronizing sequence that is suitable for collaboration relay system that it is characterized in that utilizing the permanent width of cloth zero autocorrelation sequence to construct, whole sequence is made of two parts, finishes respectively thick timing estimation, thin timing estimation and decimal frequency bias estimation, integer frequency bias and estimates; The first of sequence is by waiting short basic sequence of cycle to consist of, and wherein, it is different not to wait the cycle mainly to refer to its cycle of the basic sequence of weak point of corresponding each cooperative relaying, and the second portion of sequence waits long basic sequences of cycles to consist of by two; Short basic sequence adopts the permanent width of cloth zero autocorrelation sequence and takes full advantage of its good auto-correlation with cross correlation properties to overcome owing to partially partially affect the relay well interference that is brought with multifrequency when many; The frequency domain sequence corresponding with long basic sequence also adopts the permanent width of cloth zero autocorrelation sequence and takes full advantage of its good auto-correlation with cross correlation properties to optimize simultaneously decimal frequency bias and estimate and the performance of integer frequency bias estimation;

The method of this structure is specially:

1.) K cycle of structure is respectively L ₁, L ₂... L _KDo not wait short basic sequence of cycle, and make it satisfy the permanent width of cloth zero automatic correlative property, wherein, K is the number of via node in the collaboration relay system;

5. the sequence that) step 4 is constructed is done respectively K ring shift right bit manipulation, and the displacement side-play amount is respectively 0, m, 2m ..., (K-1) m, wherein, Be basic displacement length,

For rounding operator;