CN101742600A - Method for selecting common-frequency cell and mobile terminal - Google Patents

Abstract

The invention discloses a method for selecting a common-frequency cell and a mobile terminal. The method comprises the following steps: determining a processing signal in a first signal except for effective information of a first cell by the terminal, wherein the first signal is transmitted to the terminal by a base station, and the first cell is a cell with highest power in a reference common-frequency cell group of the terminal; acquiring initial channel impulse response of each cell in other cells according to the processing signal and basic training sequences of other cells in the reference common-frequency cell group except for the first cell, and acquiring effective diameter power according to the initial channel impulse response of each cell in other cells; and using the cell with effective diameter power more than a predetermined threshold in other cells and the first cell as a common-frequency cell of the terminal. The method and the mobile terminal can take the cell with high correlation as the common-frequency cell, can effectively improve the performance of common-frequency interference elimination in a simple mode, and solve the problem of abnormality of common-frequency interference elimination.

Description

The system of selection of co-frequency cell and portable terminal

Technical field

The present invention relates to the data network communications field, relate in particular to a kind of system of selection and portable terminal of co-frequency cell.

Background technology

As shown in Figure 1, be TD-SCDMA (Time Division-Synchronous Code DivisionMultiple Access, abbreviate TD-SCDMA as) the frame structure schematic diagram of system, in the TD-SCDMA system, by adopting the capacity of the next further expansion of identical networking technology system, though can increase the capacity of system like this, can bring the problem of phase mutual interference between co-frequency cell simultaneously.

Because the existence of co-frequency cell, terminal must be eliminated co-channel interference to guarantee demodulation performance.At present, the base station is by measuring and detect portable terminal, and according to the co-frequency cell tabulation of signal power size configure portable terminal at each time slot, it is that interference cancellation operation is carried out in each sub-district in the co-frequency cell tabulation of its configuration that portable terminal utilizes the base station.But the base station can not consider that in configuration co-frequency cell when tabulation institute the correlation of sub-district carries out the selection of sub-district, after the relatively poor sub-district of correlation is selected into co-frequency cell and tabulates, can cause the result of interference eliminated to occur unusually when carrying out interference eliminated.

At the sub-district of correlation difference influences the problem of interference eliminated owing to not considering the correlation of sub-district in the tabulation of configuration co-frequency cell in the correlation technique, effective solution is not proposed as yet at present.

Summary of the invention

At the sub-district of correlation difference influences the problem of interference eliminated owing to not considering the correlation of sub-district in the tabulation of configuration co-frequency cell in the correlation technique, the present invention proposes a kind of system of selection and portable terminal of co-frequency cell, can be that terminal is selected co-frequency cell according to the correlation of sub-district, avoid co-channel interference to eliminate unusual problem.

At the sub-district of correlation difference influences the problem of interference eliminated owing to not considering the correlation of sub-district in the tabulation of configuration co-frequency cell in the correlation technique, the present invention also proposes a kind of selection portable terminal of co-frequency cell, can be that terminal is selected co-frequency cell according to the correlation of sub-district, avoid co-channel interference to eliminate unusual problem.

Technical scheme of the present invention is achieved in that

A kind of system of selection of co-frequency cell comprises:

Terminal determines to remove in first signal processing signals of the first sub-district effective information, and wherein, described first signal sends to described terminal by the base station, the strongest sub-district of power in the reference co-frequency cell group that described first sub-district is described terminal;

Carry out channel estimating to described with reference to each sub-district in other sub-districts except that described first sub-district in the co-frequency cell group according to described processing signals, obtain the initial channel impulse response of each sub-district in described other sub-districts, and obtain the effective diameter power of this each sub-district according to the initial channel impulse response of each sub-district in described other sub-districts;

With effective diameter power in described other sub-districts greater than Pow _{Max cell}/ Thresh _ACDThe sub-district and described first sub-district as the co-frequency cell of described terminal, wherein, Pow _{Max cell}Be the effective diameter power of described first sub-district, Thresh _ACDFor activating thresholding in predetermined sub-district.

Preferably, described terminal determines that the operation of described processing signals comprises:

Described terminal obtains the initial channel impulse response of described first sub-district according to the basic training sequences of described first signal and described first sub-district, and denoising is carried out in the initial channel impulse response of described first sub-district;

Obtain secondary signal according to the described initial channel impulse response after the denoising and the basic training sequences of described first sub-district, and obtain described processing signals according to described first signal and described secondary signal.

Wherein, obtain described secondary signal according to following formula:

Rec _rebuild＝IFFT(FFT(H _{denoise_max?cell}).*FFT(Mid _max?cell))

Wherein, Rec _RebuildBe described secondary signal, H _{Denoise_max cell}Be the described initial channel impulse response after the denoising, Mid _{Max cell}Basic training sequences for described first sub-district.

Wherein, obtain described processing signals according to following formula:

Rec _IC＝Rec _old-Rec _rebuild

Wherein, Rec _ICBe described processing signals, Rec _OldBe described first signal, Rec _RebuildBe described secondary signal.

Wherein, determine the initial channel impulse response of each sub-district in described other sub-districts according to following formula:

H _{ini_intra_i}＝IFFT(FFT(Rec _IC)./FFT(Mid _{intra_i}))，i＝1…N

Wherein, H _{Ini_intra_i}Be the initial channel impulse response of i sub-district in described other sub-districts, Mid _{Intra_i}Be the basic training sequences of i sub-district, Rec _ICBe described processing signals, N is the number of described other sub-districts.

Preferably, the quantity of described co-frequency cell can demodulation greater than described terminal the situation of largest cell quantity under, described method further comprises:

Select the actual co-frequency cell of M sub-district as described terminal according to effective diameter power order from big to small from described co-frequency cell, wherein, M is the largest cell quantity that described terminal can demodulation.

A kind of portable terminal comprises:

Strong cell selecting device is used for selecting the first the strongest sub-district of power as strong sub-district from reference co-frequency cell group;

The first initial channel impulse response estimator is used for obtaining according to the basic training sequences of described first signal and described first sub-district initial channel impulse response of described first sub-district;

The signal reconstruction calculator is used for denoising is carried out in the initial channel impulse response of described first sub-district, and obtains secondary signal according to the described initial channel impulse response after the denoising and the basic training sequences of described first sub-district;

The second initial channel impulse response estimator, be used for obtaining processing signals according to described first signal and described secondary signal, and according to described processing signals and described with reference in the co-frequency cell group except that described first sub-district basic training sequences of other sub-districts, obtain the initial channel impulse response of each sub-district in described other sub-districts, wherein, described processing signals is to remove the signal of the described first sub-district effective information in described first signal;

Detector is activated in the sub-district, is used for the initial channel impulse response according to each sub-district of reference co-frequency cell, detects the effective diameter power of each sub-district, with effective diameter power in described other sub-districts greater than Pow _{Max cell}/ Thresh _ACDThe sub-district and described first sub-district as the co-frequency cell of described terminal, wherein, Pow _{Max cell}Be the effective diameter power of described first sub-district, Thresh _ACDFor activating thresholding in predetermined sub-district.

The present invention obtains the effective diameter power of each sub-district by the processing signals of removing the strongest sub-district of power effective information in definite received signal and then determines the co-frequency cell of this terminal, sub-district that can correlation is high is as co-frequency cell, effectively improve the performance that co-channel interference is eliminated, avoid the unusual problem of co-channel interference elimination appearance in the correlation technique.

Description of drawings

Fig. 1 is the frame structure schematic diagram according to the TD-SCDMA system of prior art;

Fig. 2 is the flow chart of steps according to the system of selection of the co-frequency cell of the embodiment of the invention;

Fig. 3 is the process chart of believing according to the system of selection of the co-frequency cell of the embodiment of the invention;

Fig. 4 is the composition structure connection layout according to the terminal of the embodiment of the invention.

Embodiment

In plurality of communication systems such as the TD-SCDMA system, network using identical networking technology further enlarges power system capacity, but identical networking can bring the interference between co-frequency cell, terminal is in order to improve system's receptivity, need select the same frequency tabulation of high level configuration, how to select co-frequency cell, and the number of co-frequency cell all there is fundamental influence to complexity and the performance of calculating.The present invention obtains the effective diameter power of each sub-district by the processing signals of removing the strongest sub-district of power effective information in definite received signal and then determines the co-frequency cell of this terminal, sub-district that can correlation is high is effectively improved the performance that co-channel interference is eliminated as co-frequency cell in simple mode.

Fig. 2 is the flow chart of steps of system of selection of the co-frequency cell of the embodiment of the invention, and as shown in Figure 2, the specific implementation method is as follows:

Step S201, terminal determines to remove in first signal processing signals of the first sub-district effective information, wherein, first signal is the received signal that the base station sends to terminal, first sub-district is the strongest sub-district of power in the reference co-frequency cell group of terminal, the concrete operations of this step are: terminal obtains the initial channel impulse response of first sub-district according to the basic training sequences of first signal and first sub-district, and the initial channel impulse response of first sub-district carried out denoising, afterwards, basic training sequences according to the initial channel impulse response after the denoising and first sub-district obtains secondary signal, and obtains processing signals according to first signal and secondary signal.

Step S202, according to processing signals channel estimating is carried out in each sub-district in other sub-districts except that first sub-district in the reference co-frequency cell group, obtain the initial channel impulse response of each sub-district in other sub-districts, and obtain the effective diameter power of this each sub-district according to the initial channel impulse response of each sub-district in other sub-districts.

Step S203, with effective diameter power in other sub-districts greater than Pow _{Max cell}/ Thresh _ACDThe sub-district and first sub-district as the co-frequency cell of terminal, wherein, Pow _{Max cell}Be the effective diameter power of first sub-district, Thresh _ACDFor activating thresholding in predetermined sub-district, wherein, Thresh _ACDSpan is the natural number between [4,32].

Preferably, the quantity of co-frequency cell can demodulation greater than terminal the situation of largest cell quantity under, can select the actual co-frequency cell of M sub-district as terminal from co-frequency cell according to effective diameter power order from big to small, wherein, M is the largest cell quantity that terminal can demodulation.For example, S201 is to step S203 for the process above-mentioned steps, the number of determining the co-frequency cell of terminal is 6, and according to the demodulation ability of terminal, terminal can demodulation largest cell quantity be 5, be M=5, then terminal goes out the actual co-frequency cell of 5 sub-districts as terminal with these 6 co-frequency cells according to effective diameter power selective sequential from big to small.Again for example, to step S203, the number of determining the co-frequency cell of terminal is 6 through above-mentioned steps S201, and according to the demodulation ability of terminal, terminal can demodulation largest cell quantity be 7, i.e. M=7, then terminal with these 6 co-frequency cells all as the actual co-frequency cell of terminal.

Need to prove, terminal can be as required, select flexibly to carry out the moment of above-mentioned steps S201 to step S203, for example, terminal can be carried out a step S201 to step S203 by a time slot, also can carry out a step S201 to step S203 by at interval several time slots, and perhaps terminal configuration execution in step S201 is to the cycle of step S203, to step S203, execution in step S201 is to step S203 in the time of also can behind starting up of terminal business being arranged with regard to execution in step S201 for certain hour at interval.And in correlation technique, the co-frequency cell list configuration well will can not change in a very long time afterwards, if during network condition change, will cause the co-frequency cell tabulation can't satisfy the requirement of real-time, therefore, by regular execution above-mentioned processing of the present invention, can determine in real time in time to adapt to the variation of network by co-frequency cell.

Fig. 3 is the process chart of believing according to the system of selection of the co-frequency cell of the embodiment of the invention, as shown in Figure 3, comprises following processing:

Step S301, terminal is at first tabulated (promptly from the same frequency of high level configuration, reference co-frequency cell group mentioned above) selects a strongest sub-district of power in (promptly as strong sub-district, first sub-district mentioned above), for example, high-rise when the configuration co-frequency cell, also carried the historical signal power level of co-frequency cell simultaneously.Terminal can be selected maximum signal power intensity corresponding district from the historical signal power level of each sub-district be strong sub-district.

Step S302, terminal receives from the received signal of base station (promptly, first signal mentioned above), and be that the middle Midamble sign indicating number (training sequence) of 128chips and the basic Midamble sign indicating number of strong sub-district carry out channel estimating according to length in this received signal, obtain the initial channel impulse response H of strong sub-district _{Ini_max cell}, for example, can utilize following formula to determine H _{Ini_max cell}:

H _{Ini_max cell}=IFFT (FFT (Rec _Old)/Mid _{Max cell}) wherein, Rec _OldFor being the middle Midamble sign indicating number of 128chips from length in the received signal of base station, Mid _{Max cell}Basic Midamble sign indicating number for strong sub-district.

Step S303 carries out denoising to the initial channel impulse response of strong sub-district, and utilizes channel impulse response and the strong above-mentioned received signal of sub-district basic Midamble code weight structure after the denoising of strong sub-district, obtains reconstruction signal (that is, mentioned above secondary signal).

Particularly, the every some performance number and the noise power threshold value of the initial channel impulse response of strong sub-district compare, if performance number then is changed to 0 with performance number less than this noise power threshold, otherwise keep this performance number, obtain the channel impulse response H after the denoising of strong sub-district _{Denoise_max cell}, wherein, denoising thresholding Thresh _DenoiseCan for: ${\mathrm{Thresh}}_{\mathrm{denoise}}=P_{\mathrm{denoise}}*(\underset{k=0}{\overset{127}{\mathrm{\Σ}}}{\left|h_{\mathrm{ini}\_\max \mathrm{cell}\_k}\right|}^2/128),$ Parameter P wherein _DenoiseBe adjustable parameter, can adjust, and can utilize following formula that denoising is carried out in the initial channel impulse response of strong sub-district to obtain H according to simulation performance _{Denoise_max cell}:

$H_{\mathrm{denoise}\_\max \mathrm{cell}\_k}=\left\{\begin{array}{cc}{H}_{\mathrm{ini}\_\max \mathrm{cell}\_k},& \mathrm{if}{\left|h_{\mathrm{ini}\_\max \mathrm{cell}\_k}\right|}^2>{\mathrm{Thresh}}_{\mathrm{denoise}}\\ 0,& \mathrm{or\; else}\end{array}\right..$

Then, utilize H _{Denoise_max cell}Obtain reconstruction signal with the basic Midamble sign indicating number of strong sub-district, for example, can utilize following formula to obtain reconstruction signal Rec _Rebuild:

Rec _Rebuild=IFFT (FFT (H _{Denoise_max cell}) .*FFT (Mid _{Max cell})) wherein, H _{Denoise_maxcell}Be the channel impulse response after the strong sub-district denoising, Mid _{Max cell}Basic Midamble sign indicating number for strong sub-district.

Step S304 is according to above-mentioned received signal Rec _DataObtain received signal Rec with reconstruction signal _DataThe middle processing signals of removing strong sub-district effective information for example, can utilize following formula to obtain processing signals Rec _IC:

Rec _IC＝Rec _old-Rec _rebuild。

Step S305, for in the co-frequency cell table except that strong sub-district each sub-district in other sub-districts, the basic Midamble sign indicating number according to processing signals and this sub-district obtains the initial channel impulse response of this sub-district, for example, can utilize following formula to determine the initial channel impulse response of this each sub-district:

H _{Ini_intra_i}=IFFT (FFT (Rec _IC) ./FFT (Mid _{Intra_i})), i=1 ... N, wherein, H _{Ini_intra_i}Be the initial channel impulse response of i sub-district in other sub-districts, Mid _{Intra_i}Be the basic Midamble sign indicating number of i sub-district, Rec _ICBe processing signals, N be in the co-frequency cell table except that strong sub-district the number of other sub-districts.

Step S306, initial channel impulse response according to strong sub-district, calculate the effective diameter power of this strong sub-district, and obtain the effective diameter power of each sub-district according to the initial channel impulse response of each sub-district in other sub-districts, afterwards, with the sub-district and strong sub-district co-frequency cell as terminal of effective diameter power in other sub-districts greater than predetermined threshold.For example, the effective diameter power of each sub-district is (Pow in other sub-districts _{Max cell}, Pow _{Intra_1}..., Pow _{Intra_N}), the effective diameter power of strong sub-district is Pow _{Max cell},

Wherein, the effective diameter power of strong sub-district can obtain by following formula: Pow _{Max cell}=Max (| h _j| ²), wherein, Pow _{Max cell}Be the effective diameter power of strong sub-district, h _jBe the j item in the channel impulse response array after the strong sub-district denoising, j=1,2 ..., 128.

The effective diameter power of other each sub-districts can obtain by following formula: Pow _{Intra_i}=Max (| H _{Ini_intra_i}(j) | ²), wherein, H _{Ini_intra_i}(j) be the numerical value of j item in the channel impulse response array of i sub-district in N the sub-district, j=1,2 ..., 128, i=1 ..., N.

Effective diameter power Pow i sub-district _{Intra_i}When meeting the following conditions, with the co-frequency cell of this sub-district as terminal, Pow _{Intra_i}＞Pow _{Max cell}/ Thresh _ACD, wherein, parameter Thresh _ACDBe adjustable parameter.

Step S307, the quantity N of co-frequency cell can demodulation greater than terminal the situation of largest cell quantity under, can select the actual co-frequency cell of M sub-district as terminal from co-frequency cell according to effective diameter power order from big to small, wherein, M is the largest cell quantity that terminal can demodulation.

By above-mentioned processing, can further screen the sub-district in the co-frequency cell tabulation of system configuration, effectively improve the correlation of co-frequency cell, improve the performance that co-channel interference is eliminated.

Fig. 4 is the composition structure chart of following according to the portable terminal of the embodiment of the invention, and as shown in Figure 4, this portable terminal comprises:

Strong cell selecting device 401 is used for selecting the first the strongest sub-district of power as strong sub-district from reference co-frequency cell group;

The first initial channel impulse response estimator 402 is used for obtaining according to the basic training sequences of first signal and first sub-district initial channel impulse response of first sub-district;

Signal reconstruction calculator 403 is used for denoising is carried out in the initial channel impulse response of first sub-district, and obtains secondary signal according to the basic training sequences of the initial channel impulse response after the denoising and first sub-district;

The second initial channel impulse response estimator 404, be used for obtaining processing signals according to first signal and secondary signal, and according to processing signals and with reference in the co-frequency cell group except that first sub-district basic training sequences of other sub-districts, obtain the initial channel impulse response of each sub-district in other sub-districts, wherein, processing signals is to remove the signal of the first sub-district effective information in first signal;

Detector 405 is activated in the sub-district, is used for the initial channel impulse response according to each sub-district of reference co-frequency cell, detects the effective diameter power of each sub-district, with effective diameter power in other sub-districts greater than Pow _{Max cell}/ Thresh _ACDThe sub-district and first sub-district as the co-frequency cell of terminal, wherein, Pow _{Max cell}Be the effective diameter power of first sub-district, Thresh _ACDFor activating thresholding in predetermined sub-district.

Each device in the portable terminal shown in Figure 4 is realized the selection course of co-frequency cell of the present invention according to following operation principle:

Strong cell selecting device 401 selects the strongest sub-district of power as strong sub-district from the co-frequency cell tabulation of high level configuration, for example, high-rise when the configuration co-frequency cell, also carried simultaneously the historical signal power level of co-frequency cell, strong cell selecting device 401 can be selected maximum signal power intensity corresponding district from the historical signal power level of each sub-district be strong sub-district.

The received signal that the first initial channel impulse response estimator 402 receives from the base station, and be that the basic Midamble sign indicating number of the strong sub-district selected in the middle Midamble sign indicating number of 128chips and the strong cell selecting device 401 carries out channel estimating according to length in this received signal, obtain the initial channel impulse response H of strong sub-district _{Ini_max cell}, that is, be the Midamble data Rec of 128chips with receiving length _OldWith strong zone leader be the basic Midamble sign indicating number Mid of 128chips _ServiceBe input in the first initial channel impulse response estimator 402, the algorithm of initial channel impulse response can be realized by the method for prior art.For example, can utilize following formula to determine H _{Ini_max cell}:

H _{Ini_max cell}=IFFT (FFT (Rec _Old)/Mid _{Max cell}), wherein, Rec _OldFor being the middle Midamble sign indicating number of 128chips from length in the received signal of base station, Mid _{Max cell}Basic Midamble sign indicating number for strong sub-district.

Signal reconstruction calculator 403, denoising is carried out in initial channel impulse response to the strong sub-district determined in the first initial channel impulse response estimator 402, and utilize channel impulse response and the strong above-mentioned received signal of sub-district basic Midamble code weight structure after the denoising of strong sub-district, obtain reconstruction signal.That is, the initial channel impulse response of strong sub-district is input in the signal reconstruction calculator 403, signal reconstruction calculator 403 at first carries out denoising to the initial channel impulse response of strong sub-district.

Particularly, signal reconstruction calculator 403 can carry out denoising to the initial channel impulse response of strong sub-district by following manner: the every some performance number and the noise power threshold value of the initial channel impulse response of strong sub-district compare, if performance number is less than this noise power threshold, then performance number is changed to 0, otherwise keep this performance number, obtain the channel impulse response H after the denoising of strong sub-district _{Denoise_max cell}, wherein, denoising thresholding Thresh _DenoiseCan for: ${\mathrm{Thresh}}_{\mathrm{denoise}}=P_{\mathrm{denoise}}*(\underset{k=0}{\overset{127}{\mathrm{\Σ}}}{\left|h_{\mathrm{ini}\_\max \mathrm{cell}\_k}\right|}^2/128),$ Parameter P wherein _DenoiseBe adjustable parameter, can adjust, and can utilize following formula that denoising is carried out in the initial channel impulse response of strong sub-district to obtain H according to simulation performance _{Denoise_max cell}:

$H_{\mathrm{denoise}\_\max \mathrm{cell}\_k}=\left\{\begin{array}{cc}{H}_{\mathrm{ini}\_\max \mathrm{cell}\_k},& \mathrm{if}{\left|h_{\mathrm{ini}\_\max \mathrm{cell}\_k}\right|}^2>{\mathrm{Thresh}}_{\mathrm{denoise}}\\ 0,& \mathrm{or\; else}\end{array}\right..$

Then, signal reconstruction calculator 403 utilizes H _{Denoise_max cell}Obtain reconstruction signal with the basic Midamble sign indicating number of strong sub-district, for example, can utilize following formula to obtain reconstruction signal Rec _Rebuild:

Rec _Rebuild=IFFT (FFT (H _{Denoise_max cell}) .*FFT (Mid _{Max cell})), wherein, H _{Denoise_max cell}Be the channel impulse response after the strong sub-district denoising, Mid _{Max cell}Basic Midamble sign indicating number for strong sub-district.

The second initial channel impulse response estimator 404 is used for according to above-mentioned received signal Rec _DataObtain received signal Rec with the reconstruction signal that obtains in the signal reconstruction calculator 403 _DataIn remove the processing signals of strong sub-district effective information, and in the co-frequency cell table except that strong sub-district each sub-district in other sub-districts, the basic Midamble sign indicating number according to processing signals and this sub-district obtains the initial channel impulse response of this sub-district,

For example, with original received signal Rec _DataWith reconstructed received signal Rec _RebuildBe input in the second initial channel impulse response estimator 404, the second initial channel impulse response estimator 404 at first utilizes Rec _Old-Rec _RebuildThe processing signals Rec of strong sub-district effective information is removed _ICThen, the second initial channel impulse response estimator 404 can utilize following formula to determine the initial channel impulse response of this each sub-district:

H _{Ini_intra_i}=IFFT (FFT (Rec _IC) ./FFT (Mid _{Intra_i})), i=1 ... N, wherein, H _{Ini_intra_i}Be the initial channel impulse response of i sub-district in other sub-districts, Mid _{Intra_i}Be the basic Midamble sign indicating number of i sub-district, Rec _ICBe processing signals, N be in the co-frequency cell table except that strong sub-district the number of other sub-districts.

Detector 405 is activated in the sub-district, be used for initial channel impulse response according to strong sub-district, calculate the effective diameter power of this strong sub-district, and obtain the effective diameter power of each sub-district according to the initial channel impulse response of each sub-district in other sub-districts, promptly, the initial channel impulse response of each sub-district in the co-frequency cell tabulation is input to the sub-district activates in the detector 405, detector 405 is activated in the sub-district, and impulse response detects the maximum diameter performance number of each sub-district according to initial channel; Afterwards, with the sub-district and strong sub-district co-frequency cell as terminal of effective diameter power in other sub-districts greater than predetermined threshold.For example, the effective diameter power of each sub-district is (Pow in other sub-districts _{Max cell}, Pow _{Intra_1}..., Pow _{Intra_N}), the effective diameter power of strong sub-district is Pow _{Max cell},

Wherein, the effective diameter power of strong sub-district can obtain by following formula: Pow _{Max cell}=Max (| h _j| ²), wherein, Pow _{Max cell}Be the effective diameter power of strong sub-district, h _jBe the j item in the channel impulse response array after the strong sub-district denoising, j=1,2 ..., 128.

The effective diameter power of other each sub-districts can obtain by following formula: Pow _{Intra_i}=Max (| H _{Ini_intra_i}(j) | ²), wherein, H _{Ini_intra_i}(j) be the numerical value of j item in the channel impulse response array of i sub-district in N the sub-district, j=1,2 ..., 128, i=1 ..., N.

Effective diameter power Pow i sub-district _{Intra_i}When meeting the following conditions, with the co-frequency cell of this sub-district as terminal, Pow _{Intra_i}＞Pow _{Max cell}/ Thresh _ACD, wherein, parameter Thresh _ACDBe adjustable parameter.

By said apparatus, can further screen the sub-district in the co-frequency cell tabulation of system configuration, effectively improve the correlation of co-frequency cell, improve the performance that co-channel interference is eliminated.

In sum, by means of technical scheme of the present invention, obtain the co-frequency cell of effective diameter power and then definite this terminal of each sub-district by the processing signals of removing the strongest sub-district of power effective information in definite received signal, sub-district that can correlation is high is as co-frequency cell, effectively improve the performance that co-channel interference is eliminated in simple mode, multiple stationary problem in the solution communications field (for example, can be applicable to the stationary problem of TD-SCDMA system), and implementation procedure of the present invention is simple, thereby can carry out the purpose that reaches the real-time update co-frequency cell with some cycles or rule.

The above only is preferred embodiment of the present invention, and is in order to restriction the present invention, within the spirit and principles in the present invention not all, any modification of being done, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (8)

1. the system of selection of a co-frequency cell is characterized in that, comprising:

Terminal determines to remove in first signal processing signals of the first sub-district effective information, and wherein, described first signal sends to described terminal by the base station, the strongest sub-district of power in the reference co-frequency cell group that described first sub-district is described terminal;

Carry out channel estimating to described with reference to each sub-district in other sub-districts except that described first sub-district in the co-frequency cell group according to described processing signals, obtain the initial channel impulse response of each sub-district in described other sub-districts, and obtain the effective diameter power of this each sub-district according to the initial channel impulse response of each sub-district in described other sub-districts;

With effective diameter power in described other sub-districts greater than Pow _{Max cell}/ Thresh _ACDThe sub-district and described first sub-district as the co-frequency cell of described terminal, wherein, Pow _{Max cell}Be the effective diameter power of described first sub-district, Thresh _ACDFor activating thresholding in predetermined sub-district.

2. method according to claim 1 is characterized in that, described terminal determines that the operation of described processing signals comprises:

Described terminal obtains the initial channel impulse response of described first sub-district according to the basic training sequences of described first signal and described first sub-district, and denoising is carried out in the initial channel impulse response of described first sub-district;

Obtain secondary signal according to the described initial channel impulse response after the denoising and the basic training sequences of described first sub-district, and obtain described processing signals according to described first signal and described secondary signal.

3. method according to claim 2 is characterized in that, obtains described secondary signal according to following formula:

Rec _rebuild＝IFFT(FFT(H _{denoise_max?cell}).*FFT(Mid _max?cell))

Wherein, Rec _RebuildBe described secondary signal, H _{Denoise_max cell}Be the described initial channel impulse response after the denoising, Mid _{Max cell}Be the basic training sequences of described first sub-district, FFT represents Fourier transform, and IFFT represents inverse fourier transform.

4. method according to claim 2 is characterized in that, obtains described processing signals according to following formula:

Rec _IC＝Rec _old-Rec _rebuild

Wherein, Rec _ICBe described processing signals, Rec _OldBe described first signal, Rec _RebuildBe described secondary signal.

5. according to each described method in the claim 1 to 4, it is characterized in that, carry out channel estimating to described with reference to each sub-district in other sub-districts except that described first sub-district in the co-frequency cell group according to described processing signals, the processing that obtains the initial channel impulse response of each sub-district in described other sub-districts comprises:

For described with reference in the co-frequency cell group except that described first sub-district each sub-district in other sub-districts, according to the basic training sequences of described processing signals and described sub-district, obtain the initial channel impulse response of described sub-district.

6. according to each described method in the claim 1 to 4, it is characterized in that, determine the initial channel impulse response of each sub-district in described other sub-districts according to following formula:

H _{ini_intra_i}＝IFFT(FFT(Rec _IC)./FFT(Mid _{intra_i}))，i＝1…N

Wherein, H _{Ini_intra_i}Be the initial channel impulse response of i sub-district in described other sub-districts, Mid _{Intra_i}Be the basic training sequences of i sub-district, Rec _ICBe described processing signals.

7. according to each described method in the claim 1 to 4, it is characterized in that, the quantity of described co-frequency cell can demodulation greater than described terminal the situation of largest cell quantity under, described method further comprises:

Select the actual co-frequency cell of M sub-district as described terminal according to effective diameter power order from big to small from described co-frequency cell, wherein, M is the largest cell quantity that described terminal can demodulation.

8. a portable terminal is characterized in that, comprising:

Strong cell selecting device is used for selecting the first the strongest sub-district of power as strong sub-district from reference co-frequency cell group;

The first initial channel impulse response estimator is used for obtaining according to the basic training sequences of described first signal and described first sub-district initial channel impulse response of described first sub-district;

The signal reconstruction calculator is used for denoising is carried out in the initial channel impulse response of described first sub-district, and obtains secondary signal according to the described initial channel impulse response after the denoising and the basic training sequences of described first sub-district;

The second initial channel impulse response estimator, be used for obtaining processing signals according to described first signal and described secondary signal, and according to described processing signals and described with reference in the co-frequency cell group except that described first sub-district basic training sequences of other sub-districts, obtain the initial channel impulse response of each sub-district in described other sub-districts, wherein, described processing signals is to remove the signal of the described first sub-district effective information in described first signal;

Detector is activated in the sub-district, is used for the initial channel impulse response according to each sub-district of reference co-frequency cell, detects the effective diameter power of each sub-district, with effective diameter power in described other sub-districts greater than Pow _{Max cell}/ Thresh _ACDThe sub-district and described first sub-district as the co-frequency cell of described terminal, wherein, Pow _{Max cell}Be the effective diameter power of described first sub-district, Thresh _ACDFor activating thresholding in predetermined sub-district.

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