CN101035309A - Relay method based on inter-correlation - Google Patents

Abstract

The invention is a relaying method applied to a communication system, where the communication system comprises at least a relay and multiple communicators. And the relaying method comprises the steps of: first, the relay estimates the correlativity between the received signals transmitted by all the communicators; and then, the relay broadcasts and transmits the estimated correlativity information and the processed signals so that all the communicators can use the correlativity information to improve system's receiving performance.

Description

Trunking method based on cross-correlation

Technical field

The present invention relates to a kind of relay communication method, particularly about a kind of relay communication method of utilizing each communicator transmission signals cross correlation.

Background technology

In communication system, transmission signals is to have to a certain degree correlation between communicator.In relay communications system, the transmission signals of each communicator will be transmitted by relay, relay can be estimated the cross correlation of each the communicator transmission signals that will transmit, to estimate that the cross-correlation information that obtains together sends to each communicator together with treated each communicator signal that relay receives again, thereby each communicator can utilize cross-correlation information to improve its receptivity.Here the relaying in the said relay communications system, refer to the both sides of communication or in many ways between device on the transmission link, it can comprise except that communicating pair or the direct connecting path in many ways other connecting paths, just use trunking scheme when needing by other connecting paths except that direct connecting path when communicating pair or in many ways.In our present most of communication systems, because restrictions such as transfer resource, terminal unit ability, final communicating pair or not direct communication always in many ways, but be connected to the device that some has relay function earlier, communicate by these devices, for example mobile phone is undertaken and the communicating by letter of other mobile phones or landline telephone by the base station again.

Summary of the invention

The purpose of this invention is to provide a kind of trunking method, it can make full use of each communicator transmission signals will transmit this characteristics by relay, by relay the cross-correlation information of each the communicator transmission signals that will transmit is extracted, the system that makes can make full use of cross-correlation information, to reach the purpose that improves systematic function.

According to purpose of the present invention, a kind of trunking method that is used for communication system is proposed.This communication system comprises a relay and a plurality of communicator at least.Its basic principle be relay after receiving the transmission signals of each communicator, obtain the estimation of each communicator transmission signals cross correlation through statistical estimate.Then, relay as a kind of prior information, is broadcast to each communicator together with each communicator transmission signals of handling with the estimation of this cross correlation.Each communicator utilizes cross-correlation information and the known characteristic of self signal that signal is detected after receiving broadcast singal, obtains the transmission signals of other communicators.

The specific implementation step of the method that proposes among the present invention comprises:

Step 1: relay receives the transmission signals of each communicator;

Step 2: relay is estimated the cross correlation of each communicator transmission signals of receiving;

Step 3: relay broadcasts to each communicator with certain orthogonal manner with the transmission signals of treated each communicator that had before received with the cross correlation parameter of each communicator transmission signals of estimating to obtain;

Step 4: each communicator receives from the merging transmission signals of relay and cross-correlation information, because known self the transmission signals of each communicator, so each communicator can utilize cross-correlation information, obtain the estimated value of other communicator transmission signals by self signal, as its prior information that further detects, improve the receptivity of each communicator.

Specific implementation method

Generally include a plurality of communicators in the real network.But for the ease of understanding, use a kind of typical case the most and have that the network configuration of general applicability---three nodal analysis methods are set forth trunking method proposed by the invention, and be that example is discussed with the time-division half-duplex system at this; So-called three nodal analysis methods promptly comprise a relay and two communicators.In this model, there is not DCL between two communicators of hypothesis.But application of the present invention is not limited thereto condition, is equally applicable to have between each communicator the cooperating relay system of DCL.The present invention generally is suitable for for the application scenario that all have essential characteristic in this example.

In the phase I, communicator A sends the burst s that length is N in some way _AThrough behind the channel, the length that relay R receives is the burst y of N+L-1 _{R, A}Can be expressed as:

$y_{R,A}=h_{R,A}^1{s}_A+n_R---\left(1\right)$

H wherein _{R, A} ¹Be the channel response matrix of phase I communicator A to (N+L-1) * N dimension of relay R; n _RFor relay director R degree is the noise sequence of N.

In second stage, communicator B sends the burst s that length is N in some way _BThrough behind the channel, the length that relay R receives is the burst y of N+L-1 _{R, B}Can be expressed as:

$y_{R,B}=h_{R,B}^2{s}_B+n_R---\left(2\right)$

H wherein _{R, B} ²Be the channel response matrix of second stage communicator B to (N+L-1) * N dimension of relay R.

When second stage finished, after relay was handled to received signal, the burst after the algorithm that foundation is certain is handled two groups merged, and the burst after the merging is expressed as:

s _R＝u(f(y _R，A)，g(y _R，B)) (3)

Wherein, f (), g () and u () are the function expression of sequence, represent corresponding algorithm.

Simultaneously, relay is estimated the statistics cross correlation of the transmission signal sequence of two communicators.If the statistics cross-correlation matrix of two bursts can be expressed as: $\mathrm{\ρ}=E\left[s_A{s}_B^H\right].$

Burst sR after relay R will merge in the phase III adopts suitable mode to send to communicator A and B simultaneously, for example is broadcast to communicator A and B, establishes the burst that these two communicators receive and is respectively y _{A, R}And y _{B, R}:

$y_{A,R}=h_{A,R}^3{s}_R+n_A---\left(4\right)$

$y_{B,R}=h_{B,R}^3{s}_R+n_B---\left(5\right)$

H wherein _{A, R} ³And h _{B, R} ³Be respectively the channel response matrix of phase III relay R to (N+L-1) * N dimension of communicator A and communicator B; n _AAnd n _BBe respectively communicator A and communicator director B degree is the noise sequence of N.

Estimate that the burst statistics correlation information that obtains also is broadcast to each communicator simultaneously.In broadcast channel, correlation information can be transmitted by time-multiplexed mode each communicator signal with forwarding.In order to improve efficiency of transmission, cross-correlation information can selectively be transmitted.For example, only transmit the value that cross correlation surpasses certain thresholding; The value that is lower than this thresholding will not be transmitted, and communicator can think that when handling the cross correlation between these signals is zero.In addition, cross correlation can also be quantified as several specific numerical value, the cross correlation value just is quantized the particular value of this interval correspondence in certain interval, thereby can have 2 with k bit transfer ^kThe correlation information of individual grade is given each communicator.And because the cross correlation between each communicator transmission signals all is constant in long time, so the broadcasting frequency of cross-correlation information can be very low, promptly can insert one section time slot that is used to transmit cross-correlation information, thereby can obviously not reduce message transmission rate every the frame of some.

Because the known signal that oneself sends of each communicator, the therefore influence that can from the combined signal that receives, produce according to respective algorithms elimination self signal.For example, the burst that communicator A receives after the processing can be expressed as:

x _A＝v(s _B)+n (6)

Wherein, v () is the function expression of sequence; N comprises thermal noise and error noise.

In addition, according to the correlation information of the burst of relay broadcasting, each communicator can estimate obtain the information of the other side's communicator transmission signal sequence from self burst, as its prior information that further detects, thereby improves systematic function.For example, the information of the other side's communicator transmission signal sequence of estimating according to self burst of communicator A can be expressed as:

s _B＝ρs _A (7)

Can find out more than comprehensive that the trunking method based on cross-correlation that the present invention proposes has following features:

1, takes full advantage of in the communication system cross correlation of signal transmission between each communicator;

2, relay is regularly estimated the statistics cross correlation of signal transmission between each communicator, then cross-correlation information is selectively sent out Give each communicator, as the estimation of signal transmission cross correlation between each communicator of this one-phase;

3, the cross correlation estimated information that sends according to relay of each communicator and the signal of self obtain other communicator signal transmissions Information is as the prior information of further detection;

4, the cross correlation of each communicator signal transmission is more big, and performance improvement is more big;

5, insensitive to concrete implementation method and protocol specification, possess compatibility.

In a word, the present invention is a kind of trunking method of flexible practicality, its objective is with simple structure, the easy method that realizes, fully excavates each and communicates by letter The cross correlation of signal transmission between device, the overall performance of improvement system.

Claims (7)

1, a kind of trunking method that is used for communication system, this communication system comprises a relay and a plurality of communicator at least, and each communicator is by the relay forward signal, and this trunking method comprises the following step at least:

At first, relay is received the signal from each communicator;

Then, relay is estimated the cross correlation of its each communicator signal of receiving;

Then, relay is with the cross-correlation information estimating to obtain and the transmission signals broadcast transmission in the lump of each communicator of processing in a certain way;

At last, each communicator receive cross-correlation information and handle after transmission signals after, can obtain the information of other communicator transmission signals by self signal by cross-correlation information, as its prior information that further detects.

2, the trunking method that is used for communication system described in claim 1 can be used for the communication system that all have relaying, cooperative nature.

3, the trunking method that is used for communication system described in claim 1, the burst that relay is treated forwarding carries out the cross correlation estimation, obtain reflecting the result of associating statistical nature between these bursts, the specific implementation of the algorithm for estimating of the burst cross correlation that wherein relates to is flexibly.

Whether 4, the trunking method that is used for communication system described in claim 1, relay need to send cross-correlation information is to determine according to concrete cross-correlation situation.

5, the trunking method that is used for communication system described in claim 1, relay sends cross-correlation information, and its concrete sending method that relates to is flexibly.

6, the trunking method that is used for communication system described in claim 1, communicator is estimated other communicator burst information according to the cross-correlation information of self burst and acquisition, the specific implementation of the algorithm that wherein relates to is flexibly.

7, the communicator described in claim 6 is estimated other communicator burst information according to self burst and cross-correlation information, wherein communicator judges whether to utilize cross-correlation information as the case may be and how to utilize cross-correlation information, and the specific implementation of the method that relates to is flexibly.