CN100586035C - Method for reducing reception interference in CDMA system - Google Patents

Abstract

The invention provides a device to reduce receive interference in CDMA system. Wherein, according to distribution information of interfering signal in sequence, setting weight value sequence to weighting treat signal sequence or local code sequence and normalize the opposite calculation result. This invention is simple to realize, and makes full use of interference distribution information and flexible set to weight to achieve final purpose.

Description

Be used for reducing code division multiple access system and receive the method for disturbing

Technical field

The present invention relates to a kind of wireless communication system that is applied to, particularly a kind of being applied in code division multiple access (Code-Division Multiple Access the is called for short CDMA) mobile communication system, the receiving equipment of subscriber terminal equipment or base station reduces the method for disturbing.

Background technology

Along with development of times, people comprise the requirement to communication quality and class of business etc. to the requirement of communication, and are also more and more higher.The third generation (3G) mobile communication system is grown up in order to satisfy this requirement just.It is as basic point of departure with global general-use, system synthesis, and attempt to set up the mobile comprehensive service digital network in a whole world, the function of various mobile communication system such as comprehensive honeycomb, wireless, paging, cluster, mobile data, mobile-satellite, aerial and sea, provide and the professional compatibility of fixed telecommunication network, multiple speech and the non-speech service that quality is suitable, carry out the global roaming of pocket personal terminal, thus realize human dream of anywhere, any time and anyone ideal that communicates.

That most critical is radio transmission techniques (RTT) in the 3-G (Generation Three mobile communication system).The RTT candidate motion that International Telecommunications Union in 1998 collects: except that 6 satellite interface technical schemes, the terrestrial wireless interfacing has 10 schemes, is divided into two big class: CDMA and TDMA (time division multiple access), and wherein CDMA occupies an leading position.In CDMA technology, International Telecommunications Union has accepted 3 kinds of standards at present altogether, i.e. TD-SCDMA (TD SDMA) standard of the CDMA 2000 of the W-CDMA (Wideband Code Division Multiple Access (WCDMA)) of Europe and Japan, the U.S. and China.

Compare with other 3G (Third Generation) Moblie standard, TD-SCDMA has adopted many exclusive advanced technologies, and all has outstanding advantage aspect the technology, economic two.TD-SCDMA adopts time division duplex (Time Division Duplex, abbreviation TDD), smart antenna (Smart Antenna), joint-detection technology such as (Joint Detection), availability of frequency spectrum height, can solve the problem of high population density area frequency resource anxiety, and have potential advantages aspect the multimedia services such as asymmetric mobile data such as internet browsing and video request program.

TD-SCDMA and other cdma systems are with the same, it all is a kind of CDMA multi-user mobile system, different channels adopts the mode of spread spectrum to carry out message transmission by different timeslices or by different binary code sequences under same frequency, the information of any one channel transmits and all can cause interference to other channels like this, all is a kind of noise concerning the reception of other channels.In cdma system, the address code sequence that each channel all has own distinctive confession to discern mutually.And also should be mutually orthogonal between the spectrum-spreading address code sequence of each channel.The requirement of this orthogonality all is consistent concerning any multi-address system.If channel is a desirable linear session frequency indiffusion system, simultaneity factor inside has strict synchronized relation again, guarantees that then the orthogonality of each station address intersymbol still can realize.

And actual mobile telecommunication channel is typical random time-varying channel, wherein exists the frequency diffusion of the randomness that is produced by Doppler effect, reaches the time diffusion of the randomness that is produced by the multipath transmisstion effect.The former can make received signal produce frequency selective fading, and promptly received signal different spectral component has different random fluctuation variations.The latter makes the decline of received signal generation time selectivity, and promptly received signal level can have different random fluctuations to change in time.Described these 2 kinds of declines also will reduce the capacity of system significantly except the performance of meeting severe exacerbation system.Particularly the diffusion of the time of channel makes signal can not arrive acceptance point simultaneously, and the signal between same user's adjacent-symbol is overlapped each other, and produces intersymbol interference (ISI); The diffusion of the time of channel also can worsen multiple access interference (MAI) in addition, this is because when be zero the relative time delay between the different user signal, its orthogonality is easy to guarantee, any orthogonal code can be used, but when the relative time delay between signal is non-vanishing, still keep its orthogonality will become very difficult; Moreover same frequency sub-district adjacent or at a distance, no matter be signal from its base station or subscriber terminal equipment, also can form neighbor cell or interchannel interference (ACI) to the base station of this locality or the signal of subscriber terminal equipment.

For the purpose of image, claim that the auto-correlation function value at spreading code initial point place is the main peak of correlation function; Claim the auto-correlation outside the initial point, or cross-correlation function value is the submaximum of correlation function.

Therefore the interference in the cdma system comes from the relevant submaximum of spreading code, intersymbol interference (ISI) is from the autocorrelative submaximum of spreading code, multiple access disturbs (MAI) submaximum from cross-correlation, and neighbor cell or interchannel interference (ACI) come from the non-orthogonal relevant submaximum that brings of the signal of adjacent or sub-district, distant place usually.

As shown in Figure 1, be the example of a typical cell mobile communication systems.This system is by a plurality of sub-districts 100 ₁-100 _Z(100) constitute, a base station (Base Station) 101 is wherein respectively arranged in each sub-district ₁-101 _Z(101), the subscriber terminal equipment (User Equipment is abbreviated as UE) 102 that in this sub-district service range, has some simultaneously ₁-102 _K(102).Each subscriber terminal equipment 102 by with affiliated Serving cell 100 in base station 101 keep being connected, finish and other communication equipment between communication function.The channel that communicates between subscriber terminal equipment 102 and the base station 101 is called as up channel from the channel of terminal equipment 102 101 directions to the base station, and 101 channels to terminal equipment 102 directions are called as down channel from the base station.

As shown in Figure 2, be the frame structure schematic diagram of TD-SCDMA system.This structure is according to providing in low spreading rate time division duplex (LCR-TDD) pattern (1.28Mcps) among 3G collaborative project (3GPP) the standard TS 25.221 (Release 4).The spreading rate of TD-SCDMA system is 1.28Mcps, and the length of each radio frames (Radio Frame) 200 is 10ms, and is divided into two subframes 201 that structure is identical ₀, 201 ₁(201), the length of each subframe is 5ms, i.e. 6400 chips.Wherein, the subframe 201 in each TD-SCDMA system can be divided into 7 time slots again (TS0～TS6) 202 ₀-202 ₆, two pilot time slots: descending pilot frequency time slot (DwPTS) 203 and uplink pilot time slot (UpPTS) 205, and protection interval (Guard) 204.Further, the TS0 time slot 202 ₀Be used to bearing system broadcast channel and other possible downlink traffic channel; And TS1～TS6 time slot 202 ₁-202 ₆Then be used to carry the uplink and downlink Traffic Channel.It is synchronous that uplink pilot time slot (UpPTS) 205 and descending pilot frequency time slot DwPTS time slot 203 are used to set up initial uplink and downlink respectively.TS0～TS6 time slot 202 ₀-202 ₆Length is 0.675ms or 864 chips, wherein comprise data segment Data Part1 (208) and Data Part 2 (210) that two segment lengths are 352 chips, and a middle segment length is the training sequence of 144 chips---in lead sign indicating number (Midamble) sequence 209.The Midamble sequence is significant at TD-SCDMA, comprise cell ID, channel estimating and synchronously modules such as (comprising Frequency Synchronization) all to use it.The protection that DwPTS time slot 203 comprises 32 chips at interval 211 and one long be descending synchronous code (SYNC-DL) code word 206 of 64 chips, its effect is cell ID and sets up initial synchronisation; And the UpPTS time slot comprise one long be uplink synchronous code (SYNC-UL) code word 207 of 128 chips, subscriber terminal equipment utilizes it to carry out relevant up access procedure.At TS1～TS6 time slot 202 ₁-202 ₆Between a Switching Point (transfer point) 212 is arranged.When the up-downgoing ratio was 3: 3, Switching Point (transfer point) 212 was positioned at TS3～TS4 time slot 202 ₃-202 ₄Between, at this moment, the employed up Dedicated Traffic Channel of user terminal is dispensed on TS1～TS3 time slot 202 ₁-202 ₃In, the descending TS4～TS6 time slot 202 that then is distributed in usually ₄-202 ₆In.

As shown in Figure 3, the base station 101 ₁, base station 101 ₂With base station 101 ₃Be synchronous, promptly while transmitting downstream synchronous code (SYNC-DL) is respectively SYNC-DL ₁(301), SYNC-DL ₂(302) and SYNC-DL ₃(303); Sub-district 100 ₁In subscriber terminal equipment 102 ₁After delay after a while, receive base station 101 ₁The descending synchronous code SYNC-DL that sends ₁(304); Because base station 101 ₂Apart from terminal equipment 102 ₁More farther, terminal equipment 102 ₁Receive base station 101 ₂The SYNC-DL that is sent ₂(302) can be more a little later; Simultaneously, SYNC-DL ₂(302) signal incoming terminal equipment 102 ₁Shi Huiyu SYNC-DL ₁(304) overlapping of back, thus the reception of this lap is formed interference; Terminal equipment 102 ₁Emission uplink synchronous code SYNC-UL after postponing a period of time ₁(305), delay base station 101 in the time of one section ₁Received this SYNC-UL ₁(306); Base station 101 ₃Be and base station 101 ₁The base station that distance is farther; If described distance is enough far away, base station 101 ₃The SYNC-DL that is launched ₃(303) arrive base station 101 ₁The time, meeting and base station 101 ₁Search SYNC-UL ₁(305) search window is overlapping, and therefore to signal SYNC-UL ₁(306) form interference, especially SYNC-UL ₁(306) part of signal front, the interference that is subjected to is bigger; When base station 101 ₃With base station 101 ₁Between when having the direct projection path, in the base station 101 ₁The place, interference signal SYNC-DL ₃(303) power can be far longer than the signal SYNC-UL of terminal equipment ₁(306).

As shown in Figure 4, provided SYNC-DL ₃(303) signal is to SYNC-UL ₁(306) reception forms an example of disturbing.In this example with base station 101 ₁The SYNC-UL that receives ₁(306) initial position is an initial point, uses uplink synchronous code SYNC-UL ₁As the local code sequence, slide with respect to the signal that receives, calculate the absolute value of correlation; Wherein, the local code sequence is called correlation delay, SYNC-DL with respect to the delay that signal slip between is produced ₃(303) amplitude is SYNC-UL ₁(306) 5 times, and SYNC-DL ₃(303) arrive base station 101 ₁During the place, 37 chips of rear section and SYNC-UL ₁(306) 37 of forward part chips are overlapping.The absolute value 400 of the correlation at initial point O place is the absolute value of auto-correlation main peak among Fig. 4, and the absolute value of other all non-zero correlations is the absolute value of relevant submaximum.As can be seen from Figure 4, under strongly disturbing situation, main peak 400 is difficult to be distinguished from correlated results, especially Zui Da relevant submaximum 401 its numerical value even greater than main peak 400.

Code division multiple access system is the system of a self-interference, forms mutually between the intrasystem signal and disturbs, and therefore, how correctly to parse the real information of institute's receive channel in disturbed signal, is the important topic that system faces.

In the prior art, between the energy value of each chip of the signal that receives, and be used to this signal is carried out despreading and be equal weight between each chip of the local code sequence used.Yet in the practical communication environment, the interference profile that the various piece of a burst is suffered is also inequality, and the interference that the part that has is subjected to is many, and the interference that some places are subjected to is less.

In cdma system, information data can use spreading code that it is carried out spread spectrum before emission.The method of spread spectrum is to use by spread spectrum data to multiply by spreading code.Spreading code can equivalence becomes by+1 and-1 sequence that is constituted.Suppose that spread spectrum code sequence C is [+1 ,-1 ,+1 ,-1], and be B by the data of spread spectrum, the burst behind the spread spectrum then, promptly the B sequence is [+B ,-B ,+B ,-B].

The signal A sequence of supposing one other channel is [+A ,+A ,-A ,-A], and this A sequence is to use local code sequence E[+1 ,+1 ,-1-1] data A is carried out spread spectrum obtain.Suppose that because time delay, last 1 chip in the B sequence and the 1st chip of A sequence are overlapping, the signal that receives of receiving terminal then, promptly the S sequence is [+B ,-B ,+B ,-B+A ,+A ,-A ,-A].

When receiving terminal will receive data A, use local code sequence E[+1 ,+1 ,-1-1], the S sequence is carried out despreading, the relative S sequence of local code sequence E is slided; Herein, when correlation delay is 3, the A sequence alignment in local code sequence E and the signal S sequence, calculate correlation, promptly earlier local code sequence E is multiplied each other in twos with the corresponding position step-by-step of S sequence, addition again, promptly (B+A) * 1+A * 1+ (A) * (1)+(A) * (1)=-B+4A; Divided by the length 4 of sequence E, then despreading result is A-B/4 then.As seen,, will occur anti-phasely, the situation of despreading mistake will take place when the amplitude of B during greater than 4 times of A.

On the other hand, when visible prior art uses the local code sequence that burst is carried out despreading, be to wait power between each chip.In the burst, each several part is subjected to the distribution of interference of other signals and inequality but in fact.

Obviously, the 1st of the A sequence the chip is subjected to the interference that the B sequence causes; When the amplitude of B was far longer than A, this interference was strong; And 3 chips are not subjected to the interference of B after the A sequence.And this point, in the example depicted in fig. 3 also can be apparent: base station 101 ₁The uplink synchronous code SYNC-UL that receives ₁(306), the part of its front has been subjected to coming from base station 101 ₃The SYNC-DL that is launched ₃(303) very strong interference, and remaining part is not subjected to the interference of this signal; Equally, terminal equipment 102 ₁The descending synchronous code SYNC-DL that receives ₁(304), the part of its back has been subjected to coming from base station 101 ₂The SYNC-DL that is launched ₂(302) than strong jamming, the part of its front then is not subjected to the interference of this signal, and, terminal equipment 102 ₁The closer to the base station 101 ₁, SYNC-DL ₁(304) the part that is interfered later is few more.

Summary of the invention

The object of the present invention is to provide a kind of method that code division multiple access system receives interference that is used for reducing, can make full use of the interference profile information in the burst that receives, and can choose different parameters and adjust the effect that this factor is played in reception, make the present invention have stronger adaptability, reach the purpose of the received signal of flexibility and reliability more.

For reaching above-mentioned purpose, the invention provides a kind of method that is used for reducing code division multiple access system reception interference, its technical scheme is as follows:

A kind of being used for reduced the method that code division multiple access system receives interference, is characterised in that it comprises following steps:

Steps A, utilize weights sequence W to the received signal sequence C or local code sequence E be weighted processing, obtain weighting correlation R _i, i=1 wherein, 2 ..., D ₂-D ₁+ 1;

Whether contain the signal that effective use local code sequence E carries out spread spectrum among the burst C that step B, judgement receive, promptly judge whether to exist weighting correlation R _iSatisfy H ₁≤ | R _i|≤H ₂, i=1 wherein, 2 ..., D ₂-D ₁+ 1; H ₁And H ₂Be respectively applied for and judge correlation whether effectively Lower Threshold and Upper threshold;

If not, then execution in step B.1: despreading Result_R=0 as a result is set, and returns Result_R;

If then execution in step is B.2:

Step B.2.1, H is satisfied in searching in sequence R ₁≤ | R _i|≤H ₂R under the condition _iMaximum, and give Result_R with its assignment, i=1 wherein, 2 ..., D ₂-D ₁+ 1;

Step B.2.2, with the R that stores among the Result_R _iPairing i value assignment is given Result_Q;

Step B.2.3, Result_R is carried out normalized and is returned despreading Reault_R as a result after the normalization and the retardation Result_Q between this despreading result pairing local code sequence E and the burst C.

Sequence in the described steps A is burst C, and steps A is specific as follows:

Steps A .1, the value W of each element among the weights sequence W is set _i, and 0≤W _i≤ 1, the length G of the burst C that the length of this weights sequence W equals to receive, i.e. i=1,2 ..., G;

Steps A .2, calculate when correlation delay is q, the weighting correlation that burst C and local code sequence E right to use value sequence W are weighted, and give sequence R with assignment as a result, that is:

$R_{q-{\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="C2006100233720023H2.png,C2006100233720024H1.png"\; state="\{\{state\}\}">D</figure-callout>}}_1+1}=\underset{i=\max (\mathrm{1,1}+q)}{\overset{\min (q+L,G)}{\mathrm{\&Sigma;}}}{W}_i{C}_i{E}_{i-q};$

Calculate the weights sum that is used in the above-mentioned correlation computations, and give sequence Y, that is: assignment as a result

$Y_{q-D_i+1}=\underset{i=\max (\mathrm{1,1}+q)}{\overset{\min (q+I,G)}{\mathrm{\&Sigma;}}}{W}_i;$

Wherein, D ₁Carry out the minimum value of correlation delay with respect to burst C for local code sequence E; L is the length of local code sequence E; The span of i be [max (and 1,1+q), min (q+L, G)]; When i＜0 or i＞G, W _iAnd C _iAll value is 0; When i-q＜0 or i-q＞L, E _I-qValue is 0;

The value of steps A .3, the next correlation delay amount q of calculating: q=q+1; Judge whether that all delays had all carried out correlation computations, promptly whether q carries out the maximum D of correlation delay with respect to burst C greater than local code sequence E ₂:

If q≤D ₂, then return steps A .2, continue next retardation is carried out correlation computations;

If q＞D ₂, execution in step B then.

Sequence in the described steps A is local code sequence E, and steps A is specific as follows:

Steps A .1, the value W of each element among the weights sequence W is set _i, and 0≤W _i≤ 1, the length of this weights sequence W equals the length L of local code sequence E, i.e. i=1, and 2 ..., L;

Steps A .2, calculate when correlation delay is q, the weighting correlation that burst C and local code sequence E right to use value sequence W are weighted, and give sequence R with assignment as a result, that is:

$R_{q-{\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="C2006100233720023H2.png,C2006100233720024H1.png"\; state="\{\{state\}\}">D</figure-callout>}}_1+1}=\underset{i=\max \&times;(\mathrm{1,1}+q)}{\overset{\min (q+I,G)}{\mathrm{\&Sigma;}}}{C}_i{E}_{i-q}{W}_{i-q};$

Calculate the weights sum that is used in the above-mentioned correlation computations, and give sequence Y, that is: assignment as a result

$Y_{q-D_1+1}=\underset{i=\max (\mathrm{1,1}+q)}{\overset{\min (q+I,G)}{\mathrm{\&Sigma;}}}{W}_{i-q};$

Wherein, D ₁Carry out the minimum value of correlation delay with respect to burst C for local code sequence E; G is the length of burst C; The span of i be [max (and 1,1+q), min (q+L, G)]; When i＜0 or i＞G, C _iValue is 0; When i-q＜0 or i-q＞L, W _I-qAnd E _I-qAll value is 0;

The value of steps A .3, the next correlation delay amount q of calculating: q=q+1; Judge whether that all delays had all carried out correlation computations, promptly whether q carries out the maximum D of correlation delay with respect to burst C greater than local code sequence E ₂:

If q≤D ₂, then return steps A .2, continue next retardation is carried out correlation computations;

If q＞D ₂, execution in step B then.

Among the steps A .1, the W in the weights sequence is set _iValue can comprise following steps:

Steps A .1.1, respectively measure and the estimated signal sequence in C _iSuffered interference;

Steps A .1.2, according to C in the burst _iThe corresponding W that is provided with of suffered interference _i, if C _iThe interference that is subjected to is bigger, then W _iBe set to the smaller value in 0 to 1 scope; If C _iThe interference that is subjected to is less, then W _iBe set to the higher value in 0 to 1 scope, wherein, i=1,2 ..., G.

Among the steps A .1.2, described W _iThe representative value of the smaller value in 0 to 1 scope is 0; Described W _iThe representative value of the higher value in 0 to 1 scope is 1, wherein, i=1,2 ..., G.

Among the steps A .2, the initial value of described correlation delay q is set to D ₁, its span is [D ₁, D ₂].

B.2.3, described step also comprises following steps:

Step B.2.3.1, if Y _{Result_Q}=0, V=L then is set; Otherwise V=Y is set _{Result_Q}

Step B.2.3.2, Result_R=Result_R * S * L ÷ V is set, wherein, the value of S is between 0 to 2, in the normalized process, this parameter is used for regulating the influence of the interference that the weights sum caused the despreading result;

Step B.2.3.3, Result_Q=Result_Q+D is set ₁-1;

Step B.2.3.4, return the despreading Reault_R as a result after the normalization, and the retardation Result_Q between this despreading result pairing local code sequence E and the burst C.

Step B.2.3.2 in, the representative value of described S is 1.

A kind of method that code division multiple access system receives interference that is used for reducing provided by the invention, distributed intelligence according to interference signal in the burst that receives, the weights sequence is set, weights in the part corresponding weight value sequence that is interfered bigger in the burst are less, weights in the corresponding weights sequence of the less part that is interfered in the burst are bigger, and then signal is being carried out in the correlation computations of despreading, adopt the weights sequence to be weighted simultaneously; The result of correlation computations before output according to the weights of corresponding weights sequence and, and the length of local code sequence is carried out normalization.The collocation method of weights sequence is flexible, makes the present invention have stronger adaptability, and reaching more, flexibility and reliability ground reduces the purpose that receives interference and received signal.

Description of drawings

Fig. 1 is the rough schematic of typical cell mobile communication systems in the background technology.

Fig. 2 is the frame structure schematic diagram of TD-SCDMA system in the background technology.

Fig. 3 is the signal sequence of TD-SCDMA system in the background technology and disturbs the schematic diagram that forms.

Fig. 4 is that the descending synchronous code SYNC-DL of other base stations of TD-SCDMA system in the background technology receives the schematic diagram that uplink synchronous code SYNC-UL forms larger interference to the base station.

Fig. 5 is applied to separate to the received signal in the cdma system flow chart that extends to the method that correlated results is handled for the present invention.

Fig. 6 effectively reduces other base station down synchronous codes SYNC-DL receives the interference of uplink synchronous code SYNC-UL to the base station schematic diagram for the present invention is applied to the TD-SCDMA system.

Fig. 7 effectively reduces other base station down synchronous codes SYNC-DL receives the interference of uplink synchronous code SYNC-UL to the base station schematic diagram for the present invention is applied to the TD-SCDMA system.

Embodiment

Below by Fig. 5～Fig. 7, introduce a specific embodiment of the present invention in detail, so that further understand content of the present invention.

As shown in Figure 5, the invention provides and reduce the method that receives interference in a kind of code division multiple access system, it comprises following steps:

Required array and parameter in step 1, the initialization computational process:

Step 1.1, initialization length are the array C of G, this array C be used for depositing receiver receives will be by the signal of despreading, G is that this will be by the length of the signal of despreading;

Step 1.2, initialization length are the array E of L, and this array E is used for depositing the local code sequence, and L is the length of local code sequence;

Step 1.3, initializing variable Option, S, H ₁, H ₂, D ₁, D ₂, q, Result_R and Result_Q;

Step 1.3.1, the value that Option is set are 1 or 2, and being used for the right to choose value sequence is sequence C weighting to the received signal or to local code sequence E weighting;

Step 1.3.2, the value of S is set between 0 to 2, representative value is 1, because may still exist part to disturb among the result after weighting is relevant, and the pairing weights sum of this correlated results also may be very little, to obtain the despreading result be will be divided by described weights sum because correlated results carries out normalization, and this very little inverse with value will amplify the part interference that still exists, therefore, when described parameter S is used for regulating normalization, this and the influence that is worth;

Step 1.3.3, H is set ₁, H ₂, whether effectively it is respectively applied for judges correlation Lower Threshold and Upper threshold;

Step 1.3.4, D is set ₁, D ₂, it is respectively local code sequence E carries out correlation delay with respect to burst C minimum value and maximum;

Step 1.3.5, q=D is set ₁, the correlation delay variable that q is adopted when representing to carry out correlation computations, its span is [D ₁, D ₂];

Step 1.3.6, Result_R, Result_Q are set, it returns the despreading result after the normalization respectively, and the delay between pairing local code sequence E and the burst C;

Step 1.4, initialization length are (D ₂-D ₁+ 1) array Y and R, array R are used for leaving in the process that correlation delay q changes, the correlated results sequence that calculates, and numerical value Y is used to deposit the sequence of the weights sum of described correlated results correspondence;

The value of step 2, judgement parameter Option is 1 or 2:

If Option=1, then execution in step 3, promptly be equivalent to the weights sequence that will be initialised and be provided with burst C is weighted;

If Option=2, then execution in step 4, promptly be equivalent to the weights sequence that will be initialised and be provided with local code sequence E is weighted;

Step 3, initialization length are the weights sequence array W of G;

Step 3.1, W is set _i, 0≤W wherein _i≤ 1, i=1,2 ..., G;

Step 3.2, calculate when correlation delay is q, the weighting correlation that burst C and local code sequence E right to use value sequence W are weighted, and the result deposited

Be that the sequence E that sequence W, C and process q position postpone multiplies each other and addition by the position of correspondence: $R_{q-{\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="C2006100233720023H2.png,C2006100233720024H1.png"\; state="\{\{state\}\}">D</figure-callout>}}_1+1}=\underset{i=\max (\mathrm{1,1}+q)}{\overset{\min (q+L,G)}{\mathrm{\&Sigma;}}}{W}_i{C}_i{E}_{i-q};$ Calculate the weights sum that has been used in the correlation computations, and deposit in That is: $Y_{q-{\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="C2006100233720023H2.png,C2006100233720024H1.png"\; state="\{\{state\}\}">D</figure-callout>}}_1+1}=\underset{i=\max (\mathrm{1,1}+q)}{\overset{\min (q+L,G)}{\mathrm{\&Sigma;}}}{W}_i,$ This weights sum will be used to correlated results is carried out normalization; Wherein, the span of i be 1 and 1+q in the minimum value of maximum in q+L and the G; If i＜0 or i＞G, then W _iAnd C _iAll value is 0; If i-q＜0 or i-q＞L, then E _I-qValue is 0; ∑ is represented summation, and min represents to minimize, and max represents maximizing;

Step 3.3, change correlation delay q and with it as next retardation, judge whether that all delays had all carried out correlation computations; That is: q=q+1 is set, judges that more whether q is greater than D ₂:

If q≤D ₂, then return step 3.2, continue next retardation is carried out correlation computations;

If q＞D ₂, then execution in step 5;

Step 4, initialization length are the weights sequence array W of L;

Step 4.1, W is set _i, 0≤W wherein _i≤ 1, i=1,2 ..., L;

Step 4.2, calculate when correlation delay is q, the weighting correlation that burst C and local code sequence E right to use value sequence W are weighted, and the result deposited in

Be that sequence E and the sequence W that sequence C and process postpone multiplies each other and addition by the position of correspondence: $R_{q-{\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="C2006100233720023H2.png,C2006100233720024H1.png"\; state="\{\{state\}\}">D</figure-callout>}}_1+1}=\underset{i=\max (\mathrm{1,1}+q)}{\overset{\min (q+L,G)}{\mathrm{\&Sigma;}}}{C}_i{E}_{i-q}{W}_{i-q};$ Calculate the weights that have been used in the correlation computations and, and deposit in

That is: $Y_{q-{\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="C2006100233720023H2.png,C2006100233720024H1.png"\; state="\{\{state\}\}">D</figure-callout>}}_1+1}=\underset{i=\max (\mathrm{1,1}+q)}{\overset{\min (q+L,G)}{\mathrm{\&Sigma;}}}{W}_{i-q},$ This weights sum will be used to correlated results is carried out normalization; Wherein, the span of i be 1 and 1+q in the minimum value of maximum in q+L and the G; If i＜0 or i＞G, then C _iValue is 0; If i-q＜0 or i-q＞L, then W _I-qAnd E _I-qAll value is 0;

Step 4.3, change correlation delay q and with it as next retardation, and judge whether that all delays had all carried out correlation computations; That is: q=q+1 is set, judges that more whether q is greater than D ₂:

If q≤D ₂, then return step 4.2, continue next retardation is carried out correlation computations;

If q＞D ₂, then execution in step 5;

Step 5, judge whether contain the signal that effective use local code sequence E carries out spread spectrum among the burst C, promptly judge whether to exist R _iSatisfy H ₁≤ R _i|≤H ₂, i=1 wherein, 2 ..., D ₂-D ₁+ 1, absolute value is asked in " || " expression:

If not, then execution in step 5.1: returning correlated results is 0, that is: Result_R=0 is set, and returns Result_R;

If then execution in step 5.2: in the effective correlated results that calculates, seek out the value of absolute value maximum, carry out normalized, and it is returned as last despreading result, and return the value of the pairing correlation delay q of this correlated results simultaneously, it comprises following steps:

Step 5.2.1, in array R, seek and satisfy H ₁≤ | R _i|≤H ₂R under the condition _iMaximum, and deposit it in Result_R, i=1 wherein, 2 ..., D ₂-D ₁+ 1;

Step 5.2.2, with the R that stores among the Result_R _iPairing i value deposits Result_Q in;

Step 5.2.3, initialization also are provided with variable V, if Y _{Result_Q}Be zero, V=L then is set; Otherwise V=Y is set _{Result_Q}Result_R=Result_R * S * L ÷ V is set; Result_Q=Result_Q+D is set ₁-1; Return Reault_R and Result_Q.

In the step 3.1 in the foregoing description, the W in the weights sequence is set _iValue comprises following steps:

Step 3.1.1, respectively measure and the estimated signal sequence in C _iSuffered interference;

Step 3.1.2, according to C in the burst _iThe corresponding W that is provided with of suffered interference _i, if C _iThe interference that is subjected to is bigger, then W _iBe set to the smaller value in 0 to 1 scope; If C _iThe interference that is subjected to is less, then W _iBe set to the higher value in 0 to 1 scope, wherein, i=1,2 ..., G.

Among the above-mentioned steps 3.1.2, described W _iThe representative value of the smaller value in 0 to 1 scope is 0; Described W _iThe representative value of the higher value in 0 to 1 scope is 1, wherein, i=1,2 ..., G.

In the step 3.1 in the foregoing description, to W in the weights sequence _iThe setting of value also can may further comprise the steps:

The transmit leg of main interference signal is by the emission information of this interference signal of recipient of signaled burst C among step 3.1.1, the burst C;

The position that this signal of emission information calculations of the main interference signal that the signaling that step 3.1.2, basis receive is represented is occurred in burst C, the corresponding W that is provided with _i, if C _iSuffered interference is bigger, then W _iBe set to the smaller value in 0 to 1 scope; If C _iSuffered interference is less, then W _iBe set to the higher value in 0 to 1 scope, wherein, i=1,2 ..., G.

Among the above-mentioned steps 3.1.2, described W _iThe representative value of the smaller value in 0 to 1 scope is 0; Described W _iThe representative value of the higher value in 0 to 1 scope is 1, wherein, i=1,2 ..., G.

In addition, in the step 3.1 in the foregoing description, W in the weights sequence _iThe setting of value also can comprise following steps by the recipient's of burst C upper layer module configuration:

Step 3.1.1, measurement are also judged the position that high reject signal occurred among the burst C;

Step 3.1.2, corresponding W the position of high reject signal appears, in burst C _iBe set to the smaller value in 0 to 1 scope; And other positions among the burst C, corresponding W _iBe set to the higher value in 0 to 1 scope, wherein, i=1,2 ..., G.

Among the above-mentioned steps 3.1.2, described W _iThe representative value of the smaller value in 0 to 1 scope is 0; Described W _iThe representative value of the higher value in 0 to 1 scope is 1, wherein, i=1,2 ..., G.

Further, in the TD-SCDMA system, if the high reject signal among the burst C is the descending synchronous code SYNC-DL of other sub-districts, and the local code sequence is when being uplink synchronous code SYNC-UL, then described step 3.1, weights sequence W comprises following steps by the typical method of the recipient's of burst C upper layer module configuration:

Step 3.1.1, in burst C, find the position of causing the descending synchronous code SYNC-DL of interference to occur, and determine the chip position among the pairing burst C of last chip that this descending synchronous code SYNC-DL occurs it;

Step 3.1.2, to all the chip C before the position among the determined burst C among the step 3.1.1 _i, corresponding weights W _iAll be set to the smaller value in 0 to 1 scope; And at thereafter all chip C _i, corresponding weights W _iAll be set to the higher value in 0 to 1 scope, wherein, i=1,2 ..., G.

Among the above-mentioned steps 3.1.2, described W _iThe representative value of the smaller value in 0 to 1 scope is 0; Described W _iThe representative value of the higher value in 0 to 1 scope is 1, wherein, i=1,2 ..., G.

In the step 4.1 in the foregoing description, weights sequence W value is set comprises following steps:

Step 4.1.1, respectively measure and the estimated signal sequence in C _iSuffered interference;

Step 4.1.2, according to C in the burst _iThe corresponding W that is provided with of suffered interference _I-q, if C _iSuffered interference is bigger, then W _I-qBe set to the smaller value in 0 to 1 scope; If C _iSuffered interference is less, then W _I-qBe set to the higher value in 0 to 1 scope, wherein, i-q=1,2 ..., L.

Among the above-mentioned steps 4.1.2, described W _I-qThe representative value of the smaller value in 0 to 1 scope is 0; Described W _I-qThe representative value of the higher value in 0 to 1 scope is 1, wherein, i-q=1,2 ..., L.

In the step 4.1 in the foregoing description, weights sequence W value is set comprises following steps:

The transmit leg of main interference signal is by the emission information of this interference signal of recipient of signaled burst C among step 4.1.1, the burst C;

The position that this signal of emission information calculations of the main interference signal that the signaling that step 4.1.2, basis receive is represented is occurred in burst C, the corresponding W that is provided with _I-q, if C _iSuffered interference is bigger, then W _I-qBe set to the smaller value in 0 to 1 scope; If C _iSuffered interference is less, then W _I-qBe set to the higher value in 0 to 1 scope, wherein, i-q=1,2 ..., L.

Among the above-mentioned steps 4.1.2, described W _I-qThe representative value of the smaller value in 0 to 1 scope is 0; Described W _I-qThe representative value of the higher value in 0 to 1 scope is 1, wherein, i-q=1,2 ..., L.

In the step 4.1 in the foregoing description, the setting of weights sequence W also can be by the recipient's of burst C upper layer module configuration, and the weights sequence W that upper layer module disposed can be not change with the variation of lagged variable q, and it comprises following steps:

Step 4.1.1, initialization also are provided with variable f, wherein, and 1≤f≤L;

Step 4.1.2, at weights sequence W _iIn, when 1≤i≤f, W _iBe set to the smaller value in 0 to 1 scope; When f＜i≤L, W _iBe set to the higher value in 0 to 1 scope, i=1,2 ..., L.

Among the above-mentioned steps 4.1.2, described W _iThe representative value of the smaller value in 0 to 1 scope is 0; Described W _iThe representative value of the higher value in 0 to 1 scope is 1, i=1, and 2 ..., L.

Further, above-mentioned step 4.1.2 also can be: at weights sequence W _iIn, when 1≤i≤f, W _iBe set to the higher value in 0 to 1 scope; When f＜i≤L, W _iBe set to the smaller value in 0 to 1 scope, i=1,2 ..., L.

Among the above-mentioned steps 4.1.2, described W _iThe representative value of the smaller value in 0 to 1 scope is 0; Described W _iThe representative value of the higher value in 0 to 1 scope is 1, i=1, and 2 ..., L.

Further, in the TD-SCDMA system, if the interference signal among the burst C is the descending synchronous code SYNC-DL of other sub-districts, when the local code sequence is uplink synchronous code SYNC-UL, in the then described step 4.1, weights sequence W comprises following steps by the typical method of the recipient's of burst C upper layer module configuration:

Step 4.1.1, initialization also are provided with variable:J=1 wherein, 2 ..., 8;

Step 4.1.2, at weights sequence W _iIn, when 1≤i≤f, W _iBe set to the smaller value in 0 to 1 scope; When f＜i≤L, W _iBe set to the higher value in 0 to 1 scope, i=1,2 ..., L.

Among the above-mentioned steps 4.1.1, preferred, described j value is 2, then

Among the above-mentioned steps 4.1.2, described W _iThe representative value of the smaller value in 0 to 1 scope is 0; Described W _iThe representative value of the higher value in 0 to 1 scope is 1, i=1, and 2 ..., L.

According to above-mentioned steps 4.1 described collocation methods, when j equals 2, W _iValue be 0 or 1 o'clock, be equivalent to and only adopt half SYNC-UL sign indicating number sequence of back that signal is carried out despreading.

Fig. 6 and Fig. 7 have provided respectively and have used method provided by the present invention effectively to reduce SYNC-DL ₃(303) signal is to SYNC-UL ₁(306) reception forms 2 examples disturbing.In two examples all with base station 101 ₁The SYNC-UL that receives ₁(306) initial position is an initial point, uses uplink synchronous code SYNC-UL ₁As local code sequence E, slide with respect to the burst C that receives, calculate the absolute value of correlation; Wherein, SYNC-DL ₃(303) amplitude is SYNC-UL ₁(306) 5 times, and SYNC-DL ₃(303) arrive base station 101 ₁During the place, 37 chips of rear section and SYNC-UL ₁(306) 37 of forward part chips are overlapping.Ordinate among the figure is the absolute value of sequence R.

Corresponding to the foregoing description, in Fig. 6, Option is set to 2 in the step 1; F among the step 4.1.1 is set to 2, and promptly the equal value of the first two of weights sequence W/one is 0, and back 1/2nd equal values are 1.As can be seen from Figure 6, even under strongly disturbing situation, main peak 600 also can be distinguished from correlated results, and its value is greater than the relevant submaximum 601 of maximum; Simultaneously, other relevant submaximums are obviously weakened, and promptly most interference signals are by filtering.

Corresponding to the foregoing description, in Fig. 7, Option is set to 1 in the step 1; And in the step 3.1, among the burst C corresponding to abscissa be 40 chip places before all parts, the equal value of element among its corresponding weights sequence W is 0; The element value of the remainder among the weights sequence W is 1.As can be seen from Figure 7, under strongly disturbing situation, correlated results is not interfered, and main peak 700 is easy to be distinguished, and interfere information is by filtering.

Below by a specific embodiment, compare with background technology, further specify the present invention:

In cdma system, information data can use spreading code that it is carried out spread spectrum before emission.The method of spread spectrum is to use by spread spectrum data to multiply by spreading code.Spreading code can equivalence becomes by+1 and-1 sequence that is constituted.Suppose that spread spectrum code sequence C is [+1 ,-1 ,+1 ,-1], and be B by the data of spread spectrum, the burst behind the spread spectrum then, promptly the B sequence is [+B ,-B ,+B ,-B].

The signal A sequence of supposing one other channel is [+A ,+A ,-A ,-A], and this A sequence is to use local code sequence E[+1 ,+1 ,-1-1] data A is carried out spread spectrum obtain.Suppose that because time delay, last 1 chip in the B sequence and the 1st chip of A sequence are overlapping, the signal that receives of receiving terminal then, promptly the S sequence is [+B ,-B ,+B ,-B+A ,+A ,-A ,-A].

In background technology, when receiving terminal will receive data A, use local code sequence E[+1 ,+1 ,-1-1], the S sequence is carried out despreading, the relative S sequence of local code sequence E is slided; Herein, when correlation delay is 3, the A sequence alignment in local code sequence E and the signal S sequence, calculate correlation, promptly earlier local code sequence E is multiplied each other in twos with the corresponding position step-by-step of S sequence, addition again, promptly (B+A) * 1+A * 1+ (A) * (1)+(A) * (1)=-B+4A; Divided by the length 4 of sequence E, then despreading result is A-B/4 then.As seen,, will occur anti-phasely, the situation of despreading mistake will take place when the amplitude of B during greater than 4 times of A.

And adopt the inventive method, can reduce the weights of the 1st chip of local code sequence E by the method for weighting, and then reduce of the interference of B sequence the A sequence; It is [w that weights sequence W promptly is set ₁, w ₂, w ₃, w ₄], w wherein ₁Be taken at the smaller value in 0 to 1 scope, w ₂, w ₃And w ₄Be taken at the higher value in 0 to 1 scope.Right to use value sequence W is to local code sequence E weighting, and the local code sequence E after the weighting is [w ₁, w ₂,-w ₃,-w ₄].When correlation delay is 3, use the local code sequence E after the weighting that the S sequence that receives is carried out despreading, correlated results be (B+A) * w ₁+ A * w ₂+ (A) * (w ₃)+(-A) * (w ₄)=A * (w ₁-w ₂+ w ₃+ w ₄)-B * w ₁Again divided by weights sum (w ₁+ w ₂+ w ₃+ w ₄), the result who obtains the weighting despreading is A-B * w ₁÷ (w ₁+ w ₂+ w ₃+ w ₄).As can be seen, because w ₁Be taken at the smaller value in 0 to 1 scope, so even the amplitude of B is far longer than A, the suffered interference of despreading result also can be very little; And special, work as w ₁When getting representative value 0, the despreading result will not be subjected to any interference.

The method of above-mentioned method for local code sequence E is weighted, in addition, the present invention also can be weighted burst S.The weights sequence W that be provided with this moment is [w ₁, w ₂, w ₃, w ₄, w ₅, w ₆, w ₇], will position corresponding weights: the w that A sequence and A sequence may be subjected to larger interference can not appear in the S sequence ₁, w ₂, w ₃And w ₄Be set to the smaller value in 0 to 1 scope, get representative value 0 herein; The weights that the A sequence is interfered the part correspondence less: w ₅, w ₆And w ₇Be set to the higher value in 0 to 1 scope, get representative value 1 herein.Then the burst S after the weighting is [0,0,0,0 ,+A ,-A ,-A], and being easy to calculate correlated results is 3A.In the time of the A sequence alignment among local code sequence E and the sequence S, pairing weights sequence is [w ₄, w ₅, w ₆, w ₇], i.e. [0,1,1,1], then weights and be 3, therefore with correlated results 3A divided by after 3, promptly correct despreading goes out data A.

Therefore the present invention is equivalent to reduce or removes a part of burst or the influence of a part of local code sequence in despreading is calculated, and when the interference that is subjected to is very strong, can improve the correctness and the reliability of despreading.For example in the TD-SCDMA system, when the descending synchronous code SYNC-DL of the adjacent base station that is occurred received the situation of the strong interference that uplink synchronous code SYNC-UL caused to this cell base station, effect of the present invention was very tangible; Because this moment, the energy of SYNC-DL is far longer than the energy of SYNC-UL, and just disturbs the part of SYNC-UL front, if by existing decoding technology, SYNC-UL can't be by correct despreading; And in a sub-district, the uplink synchronous code SYNC-UL number that the base station received simultaneously is also few, be generally 1, even this means that the front is subjected to the strong part of disturbing in the uplink synchronous code SYNC-UL signal that receives of deletion base station, and only to the part despreading of back, but can be correctly reliably despreading go out information.

A kind of method that code division multiple access system receives interference that is used for reducing provided by the invention, simply, be easy to realize, made full use of the interference profile information in the sign indicating number sequence of received signal, with the flexible setting of the weights that correlation computations is weighted, reached and reduced the purpose that receives interference.

Though above described the present invention by embodiment, those of ordinary skills know, the present invention has many distortion and variation and does not break away from spirit of the present invention, appended claim will comprise these distortion and variation.

Claims (8)

1, a kind of being used for reduced the method that code division multiple access system receives interference, is characterised in that it comprises following steps:

Steps A, utilize weights sequence W to the received signal sequence C or local code sequence E be weighted processing, obtain weighting correlation R _i, i=1 wherein, 2 ..., D ₂-D ₁+ 1;

Whether contain the signal that effective use local code sequence E carries out spread spectrum among the burst C that step B, judgement receive, promptly judge whether to exist weighting correlation R _iSatisfy H ₁≤ | R _i|≤H ₂, i=1 wherein, 2 ..., D ₂-D ₁+ 1; H ₁And H ₂Be respectively applied for and judge correlation whether effectively Lower Threshold and Upper threshold; D ₁And D ₂Be respectively local code sequence E and carry out the minimum value and the maximum of correlation delay with respect to burst C;

If not, then execution in step B.1: despreading Result_R=0 as a result is set, and returns Result_R;

If then execution in step is B.2:

Step B.2.1, H is satisfied in searching in sequence R ₁≤ | R _i|≤H ₂R under the condition _iMaximum, and give Result_R with its assignment, i=1 wherein, 2 ..., D ₂-D ₁+ 1;

Step B.2.2, with the R that stores among the Result_R _iPairing i value assignment is given Result_Q;

Step B.2.3, Result_R is carried out normalized and is returned despreading Reault_R as a result after the normalization and the retardation Result_Q between this despreading result pairing local code sequence E and the burst C.

2, as claimed in claim 1 being used for reduced the method that code division multiple access system receives interference, it is characterized in that the sequence in the described steps A is the burst C that receives, and steps A is specific as follows:

Steps A .1, the value W of each element among the weights sequence W is set _i, and 0≤W _i≤ 1, the length of this weights sequence W equals the length G of burst C, i.e. i=1, and 2 ..., G;

Steps A .2, calculate when correlation delay is q, the weighting correlation that burst C and local code sequence E right to use value sequence W are weighted, and give sequence R with assignment as a result, that is:

$R_{q-D_1+1}=\underset{i=\max (\mathrm{1,1}+q)}{\overset{\min (q+L,G)}{\mathrm{\&Sigma;}}}{W}_i{C}_i{E}_{i-q};$

Calculate the weights sum that is used in the above-mentioned correlation computations, and give sequence Y, that is: assignment as a result

$Y_{q-D_1+1}=\underset{i=\max (\mathrm{1,1}+q)}{\overset{\min (q+L,G)}{\mathrm{\&Sigma;}}}{W}_i;$

Wherein, D ₁Carry out the minimum value of correlation delay with respect to burst C for local code sequence E; L is the length of local code sequence E; The span of i be [max (and 1,1+q), min (q+L, G)]; When i＜0 or i＞G, W _iAnd C _iAll value is 0; When i-q＜0 or i-q＞L, E _I-qValue is 0;

The value of steps A .3, the next correlation delay amount q of calculating: q=q+1; Judge whether that all delays had all carried out correlation computations, promptly whether q carries out the maximum D of correlation delay with respect to burst C greater than local code sequence E ₂:

If q≤D ₂, then return steps A .2, continue next retardation is carried out correlation computations;

If q＞D ₂, execution in step B then.

3, as claimed in claim 1 being used for reduced the method that code division multiple access system receives interference, it is characterized in that the sequence in the described steps A is local code sequence E, and steps A is specific as follows:

Steps A .1, the value W of each element among the weights sequence W is set _i, and 0≤W _i≤ 1, the length of this weights sequence W equals the length L of local code sequence E, i.e. i=1, and 2 ..., L;

Steps A .2, calculate when correlation delay is q, the weighting correlation that burst C and local code sequence E right to use value sequence W are weighted, and give sequence R with assignment as a result, that is:

$R_{q-D_1+1}=\underset{i=\max (\mathrm{1,1}+q)}{\overset{\min (q+L,G)}{\mathrm{\&Sigma;}}}{C}_i{E}_{i-q}{W}_{i-q};$

Calculate the weights sum that is used in the above-mentioned correlation computations, and give sequence Y, that is: assignment as a result

$Y_{q-D_1+1}=\underset{i=\max (\mathrm{1,1}+q)}{\overset{\min (q+L,G)}{\mathrm{\&Sigma;}}}{W}_{i-q};$

Wherein, D ₁Carry out the minimum value of correlation delay with respect to burst C for local code sequence E; G is the length of burst C; The span of i be [max (and 1,1+q), min (q+L, G)]; When i＜0 or i＞G, C _iValue is 0; When i-q＜0 or i-q＞L, W _I-qAnd E _I-qAll value is 0;

The value of steps A .3, the next correlation delay amount q of calculating: q=q+1; Judge whether that all delays had all carried out correlation computations, promptly whether q carries out the maximum D of correlation delay with respect to burst C greater than local code sequence E ₂:

If q≤D ₂, then return steps A .2, continue next retardation is carried out correlation computations;

If q＞D ₂, execution in step B then.

4, as claimed in claim 2 being used for reduced the method that code division multiple access system receives interference, it is characterized in that, among the steps A .1, the W in the weights sequence is set _iValue comprises following steps:

Steps A .1.1, respectively measure and the burst estimating to receive in C _iSuffered interference;

Steps A .1.2, according to C in the burst _iThe corresponding W that is provided with of suffered interference _i, if C _iThe interference that is subjected to is bigger, then W _iBe set to the smaller value in 0 to 1 scope; If C _iThe interference that is subjected to is less, then W _iBe set to the higher value in 0 to 1 scope, wherein, i=1,2 ..., G.

5, as claimed in claim 4 being used for reduced the method that code division multiple access system receives interference, it is characterized in that, and among the steps A .1.2, described W _iSmaller value in 0 to 1 scope is 0; Described W _iHigher value in 0 to 1 scope is 1, wherein, i=1,2 ..., G.

6, reduce the method that code division multiple access system receives interference as claim 2 or 3 described being used for, it is characterized in that among the steps A .2, the initial value of described correlation delay q is set to D ₁, its span is [D ₁, D ₂].

7, reduce the method that code division multiple access system receives interference as claim 2 or 3 described being used for, it is characterized in that B.2.3 described step also comprises following steps:

Step B.2.3.1, if Y _{Result_Q}=0, V=L then is set; Otherwise V=Y is set _{Result_Q}

Step B.2.3.2, Result_R=Result_R * S * L ÷ V is set, wherein, the value of S is between 0 to 2, in the normalized process, this parameter is used for regulating the influence of the interference that the weights sum caused the despreading result;

Step B.2.3.3, Result_Q=Result_Q+D is set ₁-1;

Step B.2.3.4, return the despreading Reault_R as a result after the normalization, and the retardation Result_Q between this despreading result pairing local code sequence E and the burst C.

8, as claimed in claim 7ly be used for reducing code division multiple access system and receive the method for disturbing, it is characterized in that, step B.2.3.2 in, described S value is 1.

Images