CN102082622A - UL CoMP (Uplink Coordinated Multi-Point) efficient data merging method based on direct transmission after judgment - Google Patents

Abstract

The invention discloses a UL CoMP (Uplink Coordinated Multi-Point) efficient data merging method based on direct transmission after judgment, belonging to the technical field of radio communication, and in particular relating to a multi-base-station corporative information interaction and radio communication system information merging detecting method. The method achieves the purposes of reducing the feedback quantity required by passing through an interface X2, furthest improving the system performance on the basis of the low feedback quantity, and achieving better compromise between the feedback quantity and the system performance.

Description

Based on the UL CoMP efficient data merging method of directly transmitting after the judgement

Technical field

The invention belongs to wireless communication technology field, particularly mutual the and wireless communication system information merging detection method of many base stations cooperative information.

Background technology

In radio communication, the application that communication for coordination is the most successful is exactly a cooperative multipoint transmission, and it is the enhancement mode transmission technology of wanting most of LTE Advance, is the effective ways that solve Cell Edge User and average throughput.In mobile communication system, because the UE of cell edge is in interference-limited environment, (Inter-Cell Interference ICI), can reduce this regional average throughput so generally can to adopt fractional frequency reuse modes such as (FFR) to suppress presence of intercell interference.IMT-A covers for cell edge and the requirement of capacity in order to satisfy, and must adopt technology such as coordinate multipoint (CoMP), network MIM0.

In up link,, can realize that the grand diversity in spatial domain to improve transmission performance, improves the up throughput of the UE of cell edge by the antenna number that increases by the mode that many eNB cooperations receive.This method does not need the ascending resource allocation strategy is adjusted, and is a kind of simple method.And the cooperation between base stations of up many base station reception data and data merge mode for cooperative multipoint transmission, are key issues that needs solution.

Summary of the invention

The present invention proposes the judgement back and directly transmit the method that (DT) realizes that the ascending multi-point collaboration communication data merges, adopt this method can reduce the feedback quantity that X2 interface needs in a large number, and on performance, also merge (SC) and promote much, between feedback quantity and performance, found one well to trade off than existing selection.

Innovation part of the present invention is: proposed the judgement back and directly transmitted the method that (DT) realizes that the ascending multi-point collaboration communication data merges, and revised X2 interface and need the feedback data pattern, found good balance between reduction feedback quantity and the elevator system performance.

The present invention proposes the reception data and its bit error rate that obtains by current channel conditions estimation of the collaborative base station of feedback on the basis of directly feeding back different base station reception data; Can recently detect merging by the log-likelihood that recently replaces direct every bit directly to calculate with whole Bit Error Rate Computation log-likelihood at dominant base.

1, system configuration

UL CoMP supposes that Multi-cell UE resides at eNB as shown in Figure 1 _A, eNB _BAnd eNB _CThe edge of these three websites, we select eNB _AAs the main eNB of this UE, then two other becomes auxiliary eNB.In the uplink process, the upstream data of Multi-cell UE is eNB respectively _A, eNB _BAnd eNB _CThese three websites receive.

Each eNB can carry out verification to the data flow that receives separately, between main eNB and auxiliary eNB, carry out data interaction by X2 interface then, share the information after receiving separately, the data that the last strategy of setting according to us will receive separately merge, and merge our final uplink information at main eNB.

2, based on the directly transmission of judgement back

2.1 based on the directly transmission method brief introduction of judgement back

Existing X2 interface message transmission strategy comprises to be selected to merge and two kinds of strategies of high specific merging, but there is the too high and excessive problem of X2 interface feedback quantity of the error rate respectively, we have proposed the strategy based on the direct transmission in judgement back, in the direct transmission method in judgement back, three eNB detect judgement and verification to the data that receive respectively, two kinds of check results may occur:

If a. have an eNB verification correct, then the UL transmission success.If eNB _AReceive correctly, then do not have data to transmit by X2interface, otherwise, need be from eNB _BOr eNB _CTo eNB _AThe transmission data, each upstream data bit needs the X2interface flow of 1bit.

If b. whether there is the eNB verification correct.ENB _BAnd eNB _CThe data result that will obtain after will adjudicating by X2interface directly is passed to eNB _A, need simultaneously and will estimate that by current channel conditions the bit error rate that obtains is transferred to eNB _A, at eNB _AThe result who receives is merged detection obtain final result.Each upstream data bit needs the X2interface flow (the bit-error rate results data volume is very little, can ignore) of 2bit.Suppose that the transmission data are b[n] ∈ 0,1}, (n=1 ... N).If eNB _BAnd eNB _CThe data that judgement obtains after receiving are respectively

With The judgement bit error rate is respectively P _BAnd P _CENB _ADirect reception detects the log-likelihood ratio that obtains:

$L_A\left[n\right]=\ln \frac{\mathrm{Pr}\left(b\right[n]=1)}{\mathrm{Pr}\left(b\right[n]=0)}$

Then obtaining

P _B, P _CAnd L _AAfter [n], the merging method is:

$\hat{b}\left[n\right]=\frac{1}{2}\left\{\mathrm{sign}\right[L_A\left[n\right]+(2{\hat{b}}_B\left[n\right]-1)\ln \left(\frac{1-P_B}{P_B}\right)+\left(2{\hat{b}}_C\right[n]-1)\ln \left(\frac{1-P_C}{P_C}\right)]+1\}$

2.2 based on the step of directly transmitting after the judgement

The first step: at eNB _A, eNB _BAnd eNB _CCarry out data check respectively,, then directly send and confirm transmission success to UE if there is an eNB verification correct.

Second step: if eNB _AVerification is correct, directly to the upper strata data delivery, and this transmission success.

The 3rd step: if eNB _ACheck errors, but eNB _BAnd eNB _CHave one correct, then from correct eNB to eNB _ATransmit correct data by X2 interface, by eNB _ATo the upper strata data delivery, this transmission success.

The 4th step: if all eNB check errors, then eNB _BAnd eNB _CDirectly to eNB _AData result after the transmission judgement reaches the bit error rate that each website estimates from current channel conditions.

The 5th step: use eNB _BAnd eNB _CBit error rate P _BAnd P _CCalculate log-likelihood ratio separately With $L_A\left[n\right]=\ln \frac{\mathrm{Pr}\left(b\right[n]=1)}{\mathrm{Pr}\left(b\right[n]=0)}.$

The 6th step: calculate eNB _ADirectly receive and detect the log-likelihood ratio that obtains

The 7th step: merge according to 3 websites log-likelihood ratio separately that calculates above and to draw last judgement data result:

$\hat{b}\left[n\right]=\frac{1}{2}\left\{\mathrm{sign}\right[L_A\left[n\right]+(2{\hat{b}}_B\left[n\right]-1)\ln \left(\frac{1-P_B}{P_B}\right)+\left(2{\hat{b}}_C\right[n]-1)\ln \left(\frac{1-P_C}{P_C}\right)]+1\}.$

Description of drawings

Fig. 1 UL CoMP schematic diagram.

Claims (2)

1. based on the UL CoMP efficient data merging method of directly transmitting after the judgement, when existing the eNB data check correct, directly adopt its checking data, and under all eNB data check error situations, then adopt from eNB and directly transmit judgement data and current eNB estimation bit error rate to main eNB, the bit error rate that adopts the overall channel situation to draw replaces the individual data Bit Error Rate Computation to go out log-likelihood ratio, carries out final efficient data and merges.

2. according to the described efficient data of claim 1 merging method, provide the merging processing method, comprise following step:

Step 1: at eNB _A, eNB _BAnd eNB _CCarry out data check respectively,, then directly send and confirm transmission success to UE if there is an eNB verification correct;

Step 2: if eNB _AVerification is correct, directly to the upper strata data delivery, and this transmission success;

Step 3: if eNB _ACheck errors, but eNB _BAnd eNB _CHave one correct, then from correct eNB to eNB _ATransmit correct data by X2 interface, by eNB _ATo the upper strata data delivery, this transmission success;

Step 4: if all eNB check errors, then eNB _BAnd eNB _CDirectly to eNB _AData result after the transmission judgement reaches the bit error rate that each website estimates from current channel conditions;

Step 5: use eNB _BAnd eNB _CBit error rate P _BAnd P _CCalculate log-likelihood ratio separately

With $L_A\left[n\right]=\ln \frac{\mathrm{Pr}\left(b\right[n]=1)}{\mathrm{Pr}\left(b\right[n]=0)};$

Step 6: calculate eNB _ADirectly receive and detect the log-likelihood ratio that obtains

Step 7: merge according to 3 websites log-likelihood ratio separately that calculates above and to draw last judgement data result:

$\hat{b}\left[n\right]=\frac{1}{2}\left\{\mathrm{sign}\right[L_A\left[n\right]+(2{\hat{b}}_B\left[n\right]-1)\ln \left(\frac{1-P_B}{P_B}\right)+\left(2{\hat{b}}_C\right[n]-1)\ln \left(\frac{1-P_C}{P_C}\right)]+1\}.$

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