CN106162726A - A kind of multi-cell joint detection method in TD-SCDMA system - Google Patents

Abstract

This application discloses the multi-cell joint detection method in a kind of TD-SCDMA system, including: needing in the multiple cell participating in joint-detection is detected this community of demodulated signal, all homogeneous-frequency adjacent-domains signal of this community is estimated as interference signal, the channel carrying out this community described；The result that channel according to this community described is estimated calculates interference noise general power, and described interference noise general power includes signal power and the Gaussian noise power of all homogeneous-frequency adjacent-domains；According to participating in the multiple cell of described joint-detection the channel estimation results of other each communities and the ability of multi-cell joint detection, the adjacent area interfering signal power that calculating is eliminated except this community described in addition to by multi-cell joint detection；From described interference noise general power, deduct the adjacent area interfering signal power of described elimination, obtain actual interference noise power；Carry out described multi-cell joint detection according to described actual interference noise power, determine the signal detecting result of this community described.Application the application, it is possible to increase combined detection performance.

Description

A kind of multi-cell joint detection method in TD-SCDMA system

Technical field

The application relates to the signal detection technique in communication system, how little particularly to a kind of TD-SCDMA system District's associated detecting method.

Background technology

The same with other mobile communication system, TD-SCDMA system will be in the face of problem of co-channel interference.Co-channel interference can be tight Ghost image rings the transmission quality of signal, affects the service feature of TD-SCDMA system.Same in TD-SCDMA system Frequency interference is divided into two kinds, and a kind of is in systems due to time variation and the multipath effect of radio communication channel, formation little Interference within district, mainly includes there is intersymbol interference (ISI) between same user data, and with little Multi-access inference between the user that district's other subscriber signals internal cause；Another kind is presence of intercell interference, refers to other with frequency The interference that between community, multiple user signals causes.Multiuser detection technology is used in TD-SCDMA system, Consider all users or the certain user simultaneously taking certain channel, eliminate or weaken other users to any user Impact, and detect the information of all users or certain user simultaneously.Its basic thought is relevant dry by excavating Disturb user (local area interference user and adjacent area interference user) information (time of arrival (toa), the frequency expansion sequence of use, letter Number amplitude etc.) eliminate multi-access inference, and then improve the stability of signal detection.No longer as traditional detector In time domain and frequency domain, the Signal separator of aliasing is out by the signal of multiple users to ignore in system the existence of other users.

General employing multiple cell based on minimum mean square error criterion (MMSE) connection in TD-SCDMA system at present Close detection algorithm (MCJD).Multi-cell joint detection algorithm considers the mutual interference of this community user and with frequency simultaneously The adjacent cell user interference to local area user.

Joint detection algorithm based on MMSE, system model is as follows:

E=Ad+n

Wherein e is the chip-level sequence received, and d is symbol data sequence, and n is the noise sequence of chip-level, and A is The sytem matrix being made up of channel impulse response.Joint detection algorithm based on MMSE passes through following formula to sending symbol d Estimate:

${\hat{d}}_{\mathrm{MMSE}}={(A^H{R}_n^{-1}A+R_d^{-1})}^{-1}{A}^H{R}_n^{-1}e$

Wherein R_nIt is the cross-correlation matrix of noise sequence n, R_dIt it is the cross-correlation matrix of symbol data sequence d.The most not Considering the cross-correlation coefficient on noise and symbol data time and Spatial Dimension, above formula is reduced to:

${\hat{d}}_{\mathrm{MMSE}}={(A^{H}A+{\mathrm{\σ}}^{2}I)}^{-1}{A}^{H}e$

Wherein I is unit matrix, σ²For the interference noise power estimated.Above formula is in current TD-SCDMA system The joint detection algorithm commonly used.

When using above-mentioned MMSE joint detection algorithm, need to calculate sytem matrix A and interference noise power σ²。 Sytem matrix A and interference noise power σ²The order of accuarcy calculated directly influences the performance of joint detection algorithm.

Sytem matrix A and interference noise power σ²The result then estimated according to multi-cell channel calculates.Multiple cell is believed The channel impulse response of local area and adjacent area user is estimated by the algorithm that channel estimation algorithm generally uses interference to eliminate, as Shown in following formula

h_{Local area}=h+n₁

h_{Adjacent area}=h_{Adjacent area 1}+h_{Adjacent area 2}+…+h_{Adjacent area n}+n₂

Then according to the channel impulse response h estimated_{Local area}=h+n₁Calculate interference noise power for joint-detection.

But, above-mentioned associated detecting method signal detection performance in actual applications is the highest.

Summary of the invention

The application provides the multi-cell joint detection method in a kind of TD-SCDMA system, it is possible to increase joint-detection Performance.

For achieving the above object, the application adopts the following technical scheme that:

A kind of multi-cell joint detection method in TD-SCDMA system, including:

Needing in the multiple cell participating in joint-detection is detected this community of demodulated signal, by all same frequency of this community Neighboring area signal is estimated as interference signal, the channel carrying out this community described；

The result that channel according to this community described is estimated calculates interference noise general power, described interference noise general power bag Include signal power and the Gaussian noise power of all homogeneous-frequency adjacent-domains；

According to participate in described joint-detection multiple cell in except this community described in addition to the channel estimation results of other each communities with The ability of multi-cell joint detection, calculates the adjacent area interfering signal power eliminated by multi-cell joint detection；

From described interference noise general power, deduct the adjacent area interfering signal power of described elimination, obtain actual interference noise Power；

Carry out described multi-cell joint detection according to described actual interference noise power, determine the signal inspection of this community described Survey result.

As seen from the above technical solution, by the process of the application, it is possible to cannot will eliminated in joint-detection Sub-signal power counts interference noise power, for joint-detection, so can obtain signal detection knot more accurately Really, signal detection performance is improved.

Accompanying drawing explanation

Fig. 1 is the basic procedure schematic diagram of allied signal detection method in the application.

Detailed description of the invention

In order to make the purpose of the application, technological means and advantage clearer, below in conjunction with accompanying drawing to this Shen Please be described in further details.

In the associated detecting method that background technology is given, owing to the local area channel impulse response calculated has been incited somebody to action The channel impulse response of adjacent area interference signal is separated, and the interference noise power at this moment calculated only comprises noise n₁ Power.But in a practical situation due to the restriction of base station demodulation process ability, multi-cell joint detection be only capable of by The adjacent cell signal of part is included joint-detection in and is eliminated.And the adjacent cell signal of remainder cannot include connection in Inspection eliminates, then interfere for local area.But the interference noise power that existing algorithm calculates only includes noise Power, does not include jamming power, and the valuation calculated is less than actual value, therefore this valuation is used for joint-detection Rear just cause joint inspection hydraulic performance decline.

Based on above-mentioned analysis, in the application, when carrying out channel impulse response and calculating, can the most only estimate that this is little The channel in district is estimated, and is not eliminated by the channel impulse response of adjacent cell, and adjacent cell signal is as interference signal It is retained in this cell channel estimated value.Then the power of interference noise is estimated according to interference noise algorithm for estimating, This estimated value includes all of homogeneous-frequency adjacent-domain signal power and Gaussian noise power.Examine then according to multi-plot joint How little the adjacent cell channel estimated result that the ability surveyed and multi-cell channel algorithm for estimating estimate, can include in The homogeneous-frequency adjacent-domain signal power of district's joint-detection is calculated.Finally include all of homogeneous-frequency adjacent-domain by estimate Signal power and Gaussian noise power deduct the neighboring area signal power that can be eliminated by multi-cell joint detection, just It is remaining co-channel interference signal and the power of noise.This performance number is i.e. that the co-channel interference that system is really subject to is believed Number performance number and the Gaussian noise power received and, be i.e. to need to use in multi-cell joint detection algorithm Interference noise power σ²。

Fig. 1 is the schematic flow sheet of associated detecting method in the application.As it is shown in figure 1, the method includes:

Step 101, detects this community A of demodulated signal, meter for needing in each community of participation joint-detection The channel calculating community A is estimated, by all homogeneous-frequency adjacent-domains signal as interference signal.

Wherein, channel is estimated to use existing channel estimation method, such as, uses general ZF channel Algorithm for estimating, detailed algorithm no longer describes in detail.

h_{Local area}=h+I+n=h+ (h_{Adjacent area 1}+…+h_{Adjacent area n}+ n), h is the channel impulse response that local area A is current, and I is that adjacent area is done Disturb signal, n Gaussian noise.

Step 102, calculates interference noise general power according to the channel estimation results of this community A.

Here interference noise total power value include the signal power of all homogeneous-frequency adjacent-domains of community A that receives and Gaussian noise power.The algorithm for estimating of interference noise general power uses existing general algorithm for estimating, no longer describes in detail.

(including neighboring area signal power and the noise power received)

P_IFor all homogeneous-frequency adjacent-domains interfering signal power sum received；P_{Adjacent area n}The signal power of the adjacent area n for receiving Value,For Gaussian noise performance number.

Step 103, according to the least except this in the ability of system multi-cell joint detection and each community of participation joint-detection The channel estimation results of other communities outside district A, calculates the adjacent area interference signal merit eliminated by multi-cell joint detection Rate.

h_nEstimate for the channel of the co-frequency neighbor cell that multi-cell joint detection eliminates can be included in Value, can be included into joint inspection according to Demodulation Systems ability M co-frequency neighbor cell signal altogether and eliminate.

Step 104, calculates the actual interference noise power of system.

Here, actual interference noise power σ²It is the co-channel interference signal that multi-cell joint detection system is really subject to Performance number and the Gaussian noise power received and:

Aforementioned interference noise general power is substituted into above formula, and can obtain actual interference noise power is:

Wherein P_{Adjacent area M+1}+…P_{Adjacent area n}The co-channel interference noise power that cannot eliminate for joint-detection.

Step 105, actual interference noise power σ that will calculate²Substitute into joint detection algorithm and carry out signal detection.

Such as, when using MMSE joint detection algorithm, i.e. pass throughCarry out signal Detection.

So far, the method flow in the application terminates.By above-mentioned process, it is possible to by cannot in joint-detection The a part of signal power eliminated counts interference noise power, for joint-detection, so can obtain more accurate True signal detecting result, improves signal detection performance.

The foregoing is only presently preferred embodiments of the present invention, not in order to limit the present invention, all in the present invention Spirit and principle within, any modification, equivalent substitution and improvement etc. done, should be included in the present invention protect Within the scope of protecting.

Claims (1)

1. the multi-cell joint detection method in a TD-SCDMA system, it is characterised in that including:

Needing in the multiple cell participating in joint-detection is detected this community of demodulated signal, by all same frequency of this community Neighboring area signal is estimated as interference signal, the channel carrying out this community described；

The result that channel according to this community described is estimated calculates interference noise general power, described interference noise general power bag Include signal power and the Gaussian noise power of all homogeneous-frequency adjacent-domains；

According to participate in described joint-detection multiple cell in except this community described in addition to the channel estimation results of other each communities with The ability of multi-cell joint detection, calculates the adjacent area interfering signal power eliminated by multi-cell joint detection；

From described interference noise general power, deduct the adjacent area interfering signal power of described elimination, obtain actual interference noise Power；

Carry out described multi-cell joint detection according to described actual interference noise power, determine the signal inspection of this community described Survey result.