CN101102599A - An interface/signal ratio estimation method and device in communication system - Google Patents

Abstract

The method comprises: making the channel estimation and disturbance elimination for the received intermediate data to get the channel pulse response; making the noise reduction for the channel pulse response to the valid.

Description

The method of estimation of signal interference ratio and device in a kind of communication system

Technical field

The present invention relates to field of wireless communications systems, particularly relate to a kind of signal interference ratio estimation approach and device of in the TD-SCDMA system, carrying out.

Background technology

According to of the definition of 3GPP TS25.225 agreement to signal interference ratio, the signal interference ratio in TD-SCDMA (TD SDMA) system (Signal to Interference Ratio, method of estimation SIR) is:

$\mathrm{SIR}=\frac{\mathrm{RSCP}}{\mathrm{Interference}}\×\mathrm{SF}$

Wherein SF represents spreading factor, and RSCP represents the received signal code power of specific DPCH (DPCH) and PDSCH (Physical Downlink Shared Channel), and Interference represents can not be received the interference that device is eliminated in the received signal in the same time slot.

Definition according to standard, the SIR of TD-SCDMA system estimates at several different implementation methods at present, two kinds of typical methods wherein: the first is calculated this user received signal code power (RSCP) by the matched filter despreading, and last comparing with Interference Signal Code Power (ISCP) obtains SIR; It two is directly to calculate RSCP and ISCP by the selection of active path, compares and obtains SIR for last two.By more present several methods of estimation, can draw to draw a conclusion: interference power Interference item is estimated inaccurate, can not reflect actual value; Especially under TD-SCDMA system same frequency operational environment, because the existence of co-channel interference, present SIR method of estimation more can not reflect sir value accurately.And the SIR estimated value is mainly used in closed power control and channel quality indication, and therefore under low SIR and common frequency multi-cell environment, inaccurate SIR estimated value will have a strong impact on the effect of closed power control and the accuracy of channel quality indication.

Summary of the invention

The method of estimation and the device that the purpose of this invention is to provide signal interference ratio in a kind of communication system, solve existing SIR method of estimation and can not obtain Interference Signal Code Power exactly, thereby can't obtain correct sir value, to such an extent as to have a strong impact on the technical problem of closed power control effect and accuracy of indicating channel quality.

To achieve these goals, the invention provides the method for estimation of signal interference ratio in a kind of communication system, wherein, comprise the steps:

Step 1 is carried out channel estimating and interference eliminated with the intermediate code data that receive, and obtains the channel impulse response after all area interference are eliminated;

Step 2 is carried out noise reduction process to the channel impulse response after the described interference eliminated, obtains the effective diameter information of all sub-districts;

Step 3 activates detection to described effective diameter information, obtains the activation channel impulse response of all sub-districts;

Step 4 calculates received signal code power according to described activation channel impulse response;

Step 5 calculates Interference Signal Code Power according to channel impulse response after the described interference eliminated and described activation channel impulse response;

Step 6 according to described received signal code power and described Interference Signal Code Power, calculates the estimated value of signal interference ratio.

Above-mentioned method, wherein, in described step 3, described activation detects and comprises:

Step a calculates the window performance number of each window of each sub-district behind the noise reduction;

Step b detects the maximal window performance number of this user in the Serving cell of system;

Step c, the window performance number of each window of each sub-district is compared with described maximal window performance number, if ratio is more than or equal to predetermined parameters, the activation channel impulse response of then described window correspondence is the window performance number of described window, otherwise the activation channel impulse response of described window correspondence is zero.

Above-mentioned method, wherein, described step 4 further comprises: with the active path performance number addition in the first-selected window of this user in the described Serving cell, and obtain described received signal code power according to the activated code channel number of described first-selected window.

Above-mentioned method wherein, further comprises in described step 5:

Steps A calculates the number in non-zero path in the described activation channel impulse response of each sub-district;

Step B calculates the noise power of each sub-district according to the number in described non-zero path;

Step C averages to the end average noise power with the noise power of a plurality of sub-districts, and with described average noise power as described Interference Signal Code Power.

Above-mentioned method wherein, in described step C, is selected the quantity of described a plurality of sub-districts according to the available accuracy needs.

In order to realize purpose of the present invention, the present invention also provides the estimation unit of signal interference ratio in a kind of communication system, wherein, comprise: channel estimating and interference cancellation module, be used for: the intermediate code data that receive are carried out channel estimating and interference eliminated, obtain the channel impulse response after all area interference are eliminated; The noise reduction process module is used for: the channel impulse response after the described interference eliminated is carried out noise reduction process, obtain the effective diameter information of all sub-districts; Window activates detection module, is used for: described effective diameter information is activated detection, obtain the activation channel impulse response of all sub-districts; The received signal code power computing module is used for: calculate received signal code power according to described activation channel impulse response; The Interference Signal Code Power computing module is used for: calculate Interference Signal Code Power according to channel impulse response after the described interference eliminated and described activation channel impulse response; The signal interference ratio computing module is used for: according to described received signal code power and described Interference Signal Code Power, calculate the estimated value of signal interference ratio.

Above-mentioned device, wherein, described window activates detection module and is further used for: the window performance number that calculates each window of each sub-district behind the noise reduction; Detect the maximal window performance number of this user in the Serving cell of system; The window performance number of each window of each sub-district is compared with described maximal window performance number, if ratio is more than or equal to predetermined parameters, the activation channel impulse response of then described window correspondence is the window performance number of described window, otherwise the activation channel impulse response of described window correspondence is zero.

Above-mentioned device, wherein, described received signal code power computing module is further used for: with the active path performance number addition in the first-selected window of this user in the described Serving cell, and obtain described received signal code power according to the activated code channel number of described first-selected window.

Above-mentioned device, wherein, described Interference Signal Code Power computing module is further used for: the number that calculates non-zero path in the described activation channel impulse response of each sub-district; Number according to described non-zero path is calculated the noise power of each sub-district; The noise power of a plurality of sub-districts is averaged to the end average noise power, and with described average noise power as described Interference Signal Code Power.

Above-mentioned device, wherein, described Interference Signal Code Power computing module also is used for: the quantity of selecting described a plurality of sub-districts according to the available accuracy needs.

Above-mentioned device, wherein, described communication system is a TDS-CDMA system.

Technique effect of the present invention is:

1) channel impulse response after the present invention many sub-districts of utilizing window activate to detect to obtain are activated calculates received signal code power and Interference Signal Code Power, activate detection because carried out window, so received signal code power that obtains and Interference Signal Code Power are all more accurate, so the signal interference ratio that obtains is also more accurate, and then utilizing accurately, signal interference ratio can improve the control effect of closed power and improve the accuracy of channel quality indication.

2) the present invention is in calculating the Interference Signal Code Power process, the noise power of a plurality of sub-districts is averaged, and select the quantity of the sub-district that needs average according to the available accuracy needs, and can obtain average noise power comparatively accurately, can adjust precision and amount of calculation as required again.

Description of drawings

The schematic flow sheet that Fig. 1 Signal to Interference plus Noise Ratio of the present invention is estimated.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, describe the present invention below in conjunction with the accompanying drawings and the specific embodiments.

The inventive method is the multi-cell channel estimated result that utilizes after the interference eliminated, at first obtain the information of many sub-districts effective diameter through noise reduction process, activate through window then and detect the channel impulse response that obtains after many sub-districts are activated, secondly the channel impulse response after activating by Serving cell obtains received signal code power, utilize the channel estimation results after channel estimation results after many sub-districts are activated and many area interference are eliminated again, obtain Interference Signal Code Power (Interference), RSCP is compared with Interference can obtain signal interference ratio estimated value SIR at last.

The present invention is with the example that is applied as in TD SDMA (TD-SCDMA) system.

Fig. 1 carries out the schematic flow sheet that SIR estimates in the TD-SCDMA system according to the present invention.Operating procedure concrete among the embodiment is as follows:

At first, the intermediate code data that receive are sent in channel estimating and the interference cancellation module 101.Suppose that N is co-frequency cell number (comprising Serving cell), Serving cell is cell_1.This module is at first carried out circular correlation by the intermediate code that receives with corresponding Midamble (intermediate code training sequence), obtains the channel estimation value of each sub-district, passes through interference eliminated then, obtains the channel estimation value (h after each area interference elimination _{Cell_1}, h _{Cell_2}..., h _{Cell_N}).Because channel estimating and interference eliminated are in the extensive use of mobile communication system, the person skilled in this area is all very familiar to its relevant algorithm and realization, therefore repeats no more here.

Secondly, the channel estimation results after all area interference eliminations is sent in the noise reduction process module 102.This module is determined effective diameter according to the Path selection thresholding, export channel impulse response behind all sub-district noise reductions (

).The Path selection thresholding fixes on really a variety of methods in the present mobile communication system, repeat no more here.The path power value is higher than the Path selection thresholding, all elects effective diameter as, otherwise then is noise path.

Then, the channel impulse response of all sub-districts behind the noise reduction is input to window activates in the detection module 103, this module according to window activate Threshold detection go out the channel impulse response that all sub-districts are activated (

).At first calculate each window performance number of each sub-district correspondence behind the noise reduction, that is:

$P_{n,m}=\underset{i=1}{\overset{L}{\mathrm{\Σ}}}{\left|{\stackrel{-}{h}}_{\mathrm{cell}\_n}\left(i\right)\right|}^2,m=1,...,M;n=1,...N.$

Wherein, P _{N, m}Represent the window performance number of m the window in n sub-district, L represents window long, and N represents the number of co-frequency cell, and M represents the number of window in the sub-district.

Detect the window performance number of this user maximum among the Serving cell cell_1, method is as follows:

Detect the channel impulse response of activation then by following decision criteria:

Wherein parameter beta is by default.

Then, with the channel estimation results after noise reduction and the window activation detection

In this user's channel estimation results

Be sent in the received signal code power computing module 104.This module is the active path performance number addition in the first-selected window of Serving cell (the channel estimating window width is an example with 16), and obtains receive channel sign indicating number power according to first-selected window activated code channel number.Received signal code power can be used following formulate:

$\mathrm{RSCP}=\frac{1}{K}\underset{i=1}{\overset{16}{\mathrm{\Σ}}}{\left|{\stackrel{\widetilde{-}}{h}}_{\mathrm{cell}\_1}^{\mathrm{local}}\left(i\right)\right|}^2$

Wherein, K represents the activated code channel number of first-selected window correspondence.

Then, with the channel estimation value (h after the interference eliminated _{Cell_1}, h _{Cell_2}..., h _{Cell_N}) and activate to detect through window after channel estimation value (

) be sent in the Noise Estimation module 105.This module at first calculates each sub-district

The number N in middle non-zero path _{Path, n}, calculate the noise power of each sub-district then, the noise power with each sub-district averages the last noise power-value of output at last.Each sub-district noise power calculation formula is as follows:

$P_{\mathrm{noise},n}=(\underset{i=1}{\overset{128}{\mathrm{\Σ}}}{\left|\right|h_{\mathrm{cell}\_n}^i\left|\right|}^2-\underset{i=1}{\overset{128}{\mathrm{\Σ}}}{\left|\right|{\stackrel{\widetilde{-}}{h}}_{\mathrm{cell}\_n}^i\left|\right|}^2)\×128/(128-N_{\mathrm{palh},n}),n=1,...,N$

The average noise power value that averages the noise power of a plurality of sub-districts to the end then, computing formula is as follows:

${\stackrel{-}{P}}_{\mathrm{noise}}=\frac{1}{N}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{P}_{\mathrm{noise},n}$

At last, with the RSCP value that calculates and

Be sent in the SIR estimation module 106, this module with the RSCP value with

Compare, obtain the estimated value of SIR.

As from the foregoing, the present invention can bring following technique effect:

1) channel impulse response after the present invention many sub-districts of utilizing window activate to detect to obtain are activated calculates received signal code power and Interference Signal Code Power, activate detection because carried out window, so received signal code power that obtains and Interference Signal Code Power are all more accurate, so the signal interference ratio that obtains is also more accurate, and then utilizing accurately, signal interference ratio can improve the control effect of closed power and improve the accuracy of channel quality indication.

2) the present invention is in calculating the Interference Signal Code Power process, the noise power of a plurality of sub-districts is averaged, and select the quantity of the sub-district that needs average according to the available accuracy needs, and can obtain average noise power comparatively accurately, can adjust precision and amount of calculation as required again.

More than, the present invention only is to be example with the TD-SCDMA system, but is not limited thereto, the present invention also can be used for the stationary problem of other field of wireless communications systems.

Those of ordinary skills can carry out multiple different modification to the present invention in spirit of the present invention and viewpoint.All equal variation and modifications of being done according to claims scope of the present invention are all the scope that the present invention protects.

Claims (11)

1. the method for estimation of signal interference ratio in the communication system is characterized in that, comprises the steps:

Step 1 is carried out channel estimating and interference eliminated with the intermediate code data that receive, and obtains the channel impulse response after all area interference are eliminated;

Step 2 is carried out noise reduction process to the channel impulse response after the described interference eliminated, obtains the effective diameter information of all sub-districts;

Step 3 activates detection to described effective diameter information, obtains the activation channel impulse response of all sub-districts;

Step 4 calculates received signal code power according to described activation channel impulse response;

Step 5 calculates Interference Signal Code Power according to channel impulse response after the described interference eliminated and described activation channel impulse response;

Step 6 according to described received signal code power and described Interference Signal Code Power, calculates the estimated value of signal interference ratio.

2. method according to claim 1 is characterized in that, in described step 3, described activation detects and comprises:

Step a calculates the window performance number of each window of each sub-district behind the noise reduction;

Step b detects the maximal window performance number of this user in the Serving cell of system;

Step c, the window performance number of each window of each sub-district is compared with described maximal window performance number, if ratio is more than or equal to predetermined parameters, the activation channel impulse response of then described window correspondence is the window performance number of described window, otherwise the activation channel impulse response of described window correspondence is zero.

3. method according to claim 2, it is characterized in that, described step 4 further comprises: with the active path performance number addition in the first-selected window of this user in the described Serving cell, and obtain described received signal code power according to the activated code channel number of described first-selected window.

4. according to claim 1,2 or 3 described methods, it is characterized in that, further comprise in described step 5:

Steps A calculates the number in non-zero path in the described activation channel impulse response of each sub-district;

Step B calculates the noise power of each sub-district according to the number in described non-zero path;

Step C averages to the end average noise power with the noise power of a plurality of sub-districts, and with described average noise power as described Interference Signal Code Power.

5. method according to claim 4 is characterized in that, in described step C, selects the quantity of described a plurality of sub-districts according to the available accuracy needs.

6. the estimation unit of signal interference ratio in the communication system is characterized in that, comprising:

Channel estimating and interference cancellation module are used for: the intermediate code data that receive are carried out channel estimating and interference eliminated, obtain the channel impulse response after all area interference are eliminated;

The noise reduction process module is used for: the channel impulse response after the described interference eliminated is carried out noise reduction process, obtain the effective diameter information of all sub-districts;

Window activates detection module, is used for: described effective diameter information is activated detection, obtain the activation channel impulse response of all sub-districts;

The received signal code power computing module is used for: calculate received signal code power according to described activation channel impulse response;

The Interference Signal Code Power computing module is used for: calculate Interference Signal Code Power according to channel impulse response after the described interference eliminated and described activation channel impulse response;

The signal interference ratio computing module is used for: according to described received signal code power and described Interference Signal Code Power, calculate the estimated value of signal interference ratio.

7. device according to claim 1 is characterized in that, described window activates detection module and is further used for: the window performance number that calculates each window of each sub-district behind the noise reduction; Detect the maximal window performance number of this user in the Serving cell of system; The window performance number of each window of each sub-district is compared with described maximal window performance number, if ratio is more than or equal to predetermined parameters, the activation channel impulse response of then described window correspondence is the window performance number of described window, otherwise the activation channel impulse response of described window correspondence is zero.

8. device according to claim 7, it is characterized in that, described received signal code power computing module is further used for: with the active path performance number addition in the first-selected window of this user in the described Serving cell, and obtain described received signal code power according to the activated code channel number of described first-selected window.

9. according to claim 6,7 or 8 described devices, it is characterized in that described Interference Signal Code Power computing module is further used for: the number that calculates non-zero path in the described activation channel impulse response of each sub-district; Number according to described non-zero path is calculated the noise power of each sub-district; The noise power of a plurality of sub-districts is averaged to the end average noise power, and with described average noise power as described Interference Signal Code Power.

10. device according to claim 9 is characterized in that, described Interference Signal Code Power computing module also is used for: the quantity of selecting described a plurality of sub-districts according to the available accuracy needs.

11. device according to claim 9 is characterized in that, described communication system is a TDS-CDMA system.

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