CN101110630A - Method and apparatus for eliminating descending pilot frequency time slot signal disturbance - Google Patents

Abstract

The present invention discloses a method to eliminate a downlink pilot frequency time slot signal interference, which includes procedures below: Firstly, it is necessary to obtain an estimated value of an m-1 sub-frame of downlink pilot frequency time slot signal inference. Wherein, the m is not less than 1. According to the estimated value of the m-1 sub-frame of the downlink pilot frequency time slot signal inference, an m sub-frame of uplink pilot frequency time slot signal interference is eliminated to obtain a pure m sub-frame of uplink pilot frequency time slot signal. In addition, the present invention discloses a device to eliminate downlink pilot frequency time slot signal inference, which comprises an estimated interference signal acquisition module and an interference elimination module. The present invention can simply and effectively eliminate interference of the uplink pilot frequency signals and improve performance of a base station to detect an uplink synchronous sequence.

Description

Eliminate method and device that descending pilot frequency time slot signal disturbs

Technical field

The present invention relates to mobile communication technology, be specifically related to a kind of method and device that descending pilot frequency time slot signal disturbs of eliminating.

Background technology

TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) technology is the flexible combination of FDMA (frequency division multiple access), TDMA (time division multiple access) and three kinds of basic transmission modes of CDMA (code division multiple access), one of its fundamental characteristics is under TDD (time division duplex) pattern, the mode of operation of the TDMA burst that employing transmission in the time frame that periodically repeats is basic, by periodically changing transmission direction, on same carrier wave, alternately carry out the uplink and downlink link transmission.

As shown in Figure 1, the physical channel of TD-SCDMA system adopts four-layer structure: radio frames, subframe, time slot and sign indicating number.A wireless frame length is 10ms, is divided into two 5ms subframes.Each subframe is divided into 7 conventional time slots and 3 special time slots again.These three special time slots are respectively DwPTS (descending pilot frequency time slot), GP (protection at interval) and UpPTS (uplink pilot time slot).

DwPTS in each subframe is as descending pilot frequency and design synchronously, and this time slot is that the downlink synchronous sequence SYNC_DL of 64chip (chip) and the protection of 32chip are formed at interval by length.SYNC_DL is one group of PN sign indicating number, is used to distinguish neighbor cell.UpPTS in each subframe is for setting up uplink synchronous design, when UE (subscriber equipment) is in aerial registration and at random during access state, it will at first launch UpPTS, after obtaining the replying of network, go up at PRACH (Physical Random Access Channel) and to send signaling that RRC (Radio Resource control) link sets up to RNC (radio network controller).The UpPTS time slot is made of at interval the protection of uplink synchronous sequence SYNC_UL and 32chip.SYNC_UL is one group of PN sign indicating number, is used for distinguishing different UE at access procedure.

Because the environment around the base station can produce reflection to the SYNC_DL signal, the SYNC_DL signal of reflection will enter GP time slot and UpPTS time slot.Usually, the UpPTS signal is detected in the base station from the received signal of GP time slot and UpPTS time slot.Therefore, the interference of SYNC_DL reflected signal can influence the detection of base station to the SYNC_UL signal.

In order to overcome this interference, adopt the DwPTS interference cancellation algorithm in the prior art usually, the handling process of this algorithm as shown in Figure 2, this algorithm is divided into two stages:

Phase I, eliminate the interference that reflection produces from SYNC_DL in the UpPTS signal in the current subframe that receives.

In step 201, the signal that a last subframe is received carries out Interference Estimation.

256 chips are arranged behind DwPTS, comprise the GP of 96 chips and the UpPTS of 160 chips.

The numerical value of DwPTS interference signal on ante antenna i of the 0th subframe chip is initialized as:

av ₀[ante][i]＝0，i＝1，2，...，256，ante＝1，2，...，N，

Adopt recursive mode to calculate the numerical value of DwPTS interference signal on m-1 (m＞1) ante antenna i of the subframe chip, this numerical value can be expressed as:

${\mathrm{av}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]=\frac{(P-1)\·{\mathrm{av}}_{m-2}\left[\mathrm{ante}\right]\left[i\right]+e^{j(-{\mathrm{\θ}}_{m-1})}\·\mathrm{inst}\_{\mathrm{value}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]}{P},---\left(1\right)$

i＝1，2，...，256，ante＝1，2，...，N

Wherein, N represents number of antennas, inst_value _M-1[ante] [i] is illustrated in i chip signal in the m-1 subframe that receives on ante the antenna, the SYNC_UL signal that comprise the DwPTS reflected signal, may receive and other interference signals (noise);

P is a forgetting factor;

e ^{J θ m-1}In j be the unit of imaginary number, that is: j ²=-1;

θ _M-1The phase place that adopts when launching for SYNC-DL sign indicating number in m-1 subframe DwPTS;

Inst_value _M-1[ante] [i] and av _M-1[ante] [i] is plural number.

If there is not the SYNC_UL signal to be received in the subframe in front, then at the DwPTS reflected signal under the situation stable or that slowly change, av _M-1[ante] [i] is approximately equal to the DwPTS reflected signal of i chip on ante the antenna, in the m-1 subframe.But if received the SYNC_UL signal in the subframe in front, then the influence of the SYNC_UL signal of Jie Shouing is also contained in av _M-1Among [ante] [i].

In step 202, carry out the DwPTS interference eliminated.

After the DwPTS interference eliminated, on ante the antenna, the value of i chip is in the m subframe:

$\mathrm{mod}i\_\mathrm{value}\_1_m\left[\mathrm{ante}\right]\left[i\right]=\mathrm{inst}\_{\mathrm{value}}_m\left[\mathrm{ante}\right]\left[i\right]-e^{j{\mathrm{\θ}}_m}\·{\mathrm{av}}_{m-1}\left[\mathrm{ante}\right]\left[i\right],---\left(2\right)$

i＝1，2，...，256，ante＝1，2，...，N

Wherein, θ _mThe phase place that adopts when launching for SYNC-DL sign indicating number in m subframe DwPTS.

Because the SYNC_UL signal that receives before the m subframe can be to av _M-1[ante] [i] exerts an influence, and therefore also needs from modi_value_1 _mEliminate the influence of the previous SYNC_UL signal that receives among [amte] [i], the SYNC_UL on the m subframe is detected to finish.

Second stage, the previous SYNC_UL signal that receives of compensation is to modi_value_1m[ante] [i] influence of producing.

In step 203, the signal after the previous frame detection is reconstructed.

If do not detect the SYNC_UL sign indicating number in the m-1 subframe, then the SYNC_UL signal of the m-1 subframe of reconstruct is as follows:

inst_sync1_recon _m-1[ante][i]＝0，ante＝1，2，...，N；i＝1，2，...，256.(3)

If detect at least one SYNC_UL sign indicating number in the m-1 subframe, then the SYNC_UL signal of the m-1 subframe of reconstruct is as follows:

$\mathrm{inst}\_\mathrm{sync}1\_{\mathrm{recon}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]=e^{j\left({\mathrm{\θ}}_{m-1}\right)}\·\mathrm{inst}\_{\mathrm{value}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]-{\mathrm{av}}_{m-2}\left[\mathrm{ante}\right]\left[i\right],$

ante＝1，2，...，N；i＝1，2，...，256.(4)

Suppose on ante the antenna of reconstruct, the signal of i chip of m-1 subframe is inst_sync1_recon _M-1[ante] [i], and suppose that the SYNC_UL signal is to modi_value_1 before the m subframe _mThe influence of [ante] [i] is av_syncl_recon _M-1[ante] [i], then

In step 204, by following formula calculate on ante the antenna in compensation back, the value of i chip is in the m subframe:

$\mathrm{mod}i\_\mathrm{value}\_2_m\left[\mathrm{ante}\right]\left[i\right]=$

$\mathrm{mod}i\_\mathrm{value}\_1_m\left[\mathrm{ante}\right]\left[i\right]+e^{j{\mathrm{\θ}}_m}\·\mathrm{av}\_\mathrm{aync}1\_{\mathrm{recon}}_{m-1}\left[\mathrm{ante}\right]\left[i\right],---\left(5\right)$

i＝1，2，...256，ante＝1，2，...8

Wherein, av_sync1_recon _M-1Can calculate by following formula:

$\mathrm{av}\_\mathrm{sync}1-{\mathrm{recon}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]=$

$\frac{(P-1)\·\mathrm{av}\_\mathrm{sync}1\_{\mathrm{recon}}_{m-2}\left[\mathrm{ante}\right]\left[i\right]+\mathrm{inst}\_\mathrm{sync}1\_{\mathrm{recon}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]}{P}---\left(6\right)$

i＝1，2，...256，ante＝1，2，...N

In step 205, the clean UpPTS signal modi_value_2 that utilizes above-mentioned steps 204 to obtain _m[ante] [i] finishes synchronization detection process.

By above-mentioned flow process as seen, this algorithm carries out interference eliminated earlier, and then carries out signal compensation, realizes complexity, need take more hardware and software resource.

And in the above-mentioned Interference Estimation that the reflected signal of down-bound pilot frequency signal is caused, the duration of the reflected signal of down-bound pilot frequency signal has been considered to cover the detection range of whole uplink pilot signal, has promptly continued 256 chips.In fact, the duration of the reflected signal of down-bound pilot frequency signal can not cover the detection range of whole uplink pilot signal.Therefore, existing algorithm not only increased the amount of calculation during algorithm is realized, and the surveyed area that can not interfere with at the reflected signal of down-bound pilot frequency signal is introduced interference.

Summary of the invention

Main purpose of the present invention provides a kind of method that descending pilot frequency time slot signal disturbs of eliminating, the SYNC_DL signal is to the interference of uplink pilot time slot signal in the descending pilot frequency time slot in the wireless channel simply, optimally to eliminate, and the raising base station is to the detection performance of SYN-UL.

Another object of the present invention provides a kind of device that descending pilot frequency time slot signal disturbs of eliminating, and eliminates the interference in the uplink pilot signal simply, effectively, guarantees the correctness that uplink pilot signal receives.

For this reason, the invention provides following technical scheme:

A kind of method of eliminating the descending pilot frequency time slot signal interference, described method comprises:

A, obtain m-1 subframe descending pilot frequency time slot signal Interference Estimation value, wherein, m＞=1;

B, m subframe uplink pilot frequency time slot signal is carried out interference eliminated, obtain the uplink pilot time slot signal of pure m subframe according to m-1 subframe descending pilot frequency time slot signal Interference Estimation value.

Described method further comprises: the descending pilot frequency time slot signal Interference Estimation value of setting the 0th subframe is 0.

The described step of obtaining m-1 subframe descending pilot frequency time slot signal Interference Estimation value comprises:

The uplink pilot time slot signal of the pure m-1 subframe that obtains is carried out uplink synchronous sequence SYNC_UL sign indicating number to be detected;

Determine m-1 subframe descending pilot frequency time slot signal Interference Estimation value according to testing result.

Describedly determine that according to testing result the step of m-1 subframe descending pilot frequency time slot signal Interference Estimation value comprises:

If in the uplink pilot time slot signal of described m-1 subframe, do not detect the SYNC_UL sign indicating number, then calculate m-1 subframe descending pilot frequency time slot signal Interference Estimation value by recursive fashion;

If in the uplink pilot time slot signal of m-1 subframe, detect at least one SYNC_UL sign indicating number, then with m-2 subframe descending pilot frequency time slot interference signal estimated value as m-1 subframe descending pilot frequency time slot interference signal estimated value.

Describedly estimate that by recursive fashion the step of m-1 subframe descending pilot frequency time slot signal Interference Estimation value is specially:

Estimate on each antenna descending pilot frequency time slot signal Interference Estimation value in each chip by following formula:

${\mathrm{av}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]=\frac{(P-1)\·{\mathrm{av}}_{m-2}\left[\mathrm{ante}\right]\left[i\right]+e^{j(-{\mathrm{\θ}}_{m-1})}\·\mathrm{inst}\_{\mathrm{value}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]}{P},$

i＝1，2，...，Num，ante＝1，2，...，N；

Wherein, N is a number of antennas;

Num is the scope of the interference that causes of down-bound pilot frequency signal;

e ^{J (θ m-1)}In j be the unit of imaginary number, j ²=-1;

θ _M-1The phase place that adopts when launching for SYNC-DL sign indicating number in m-1 subframe descending pilot frequency time slot signal;

Av _M-1[ante] [i] is the Interference Estimation value of m-1 subframe descending pilot frequency time slot signal at ante antenna i chip;

Inst_value _M-1[ante] [i] is i chip signal in the m-1 frame on ante the antenna that is received;

P is a forgetting factor.

Describedly determine that according to testing result the step of m-1 subframe descending pilot frequency time slot signal Interference Estimation value further comprises:

If carried out the antenna correction in the m-1 subframe, then with m-2 subframe descending pilot frequency time slot interference signal estimated value as m-1 subframe descending pilot frequency time slot interference signal estimated value.

Described step B is specially:

Calculate the uplink pilot time slot signal of m subframe according to following formula:

$\mathrm{mod}i\_\mathrm{value}\_1_m\left[\mathrm{ante}\right]\left[i\right]=\mathrm{inst}\_{\mathrm{value}}_m\left[\mathrm{ante}\right]\left[i\right]-e^{j{\mathrm{\θ}}_m}{\mathrm{av}}_{m-1}\left[\mathrm{ante}\right]\left[i\right],$

i＝1，2，...，Num；ante＝1，2，...，N；

Wherein, modi_value_1 _m[ante] [i] is i chip signal on ante antenna of m subframe after the descending pilot frequency time slot signal interference eliminated;

Inst_value _m[ante] [i] is i chip signal in the m subframe on the ante antenna that is received;

Av _M-1[ante] [i] is descending pilot frequency time slot signal Interference Estimation value in i chip on the ante antenna in the m-1 subframe;

θ _mThe phase place that adopts when launching for SYNC-DL sign indicating number in m subframe descending pilot frequency time slot signal;

Num is the scope that down-bound pilot frequency signal causes interference.

Described step B further comprises:

When Num＜256, carry out following assignment and calculate:

modi_value_1 _m[ante][i]＝inst_value _m[ante][i]，

i＝Num+1，...，256；ante＝1，2，...，N。

A kind of device of eliminating the descending pilot frequency time slot signal interference comprises:

Interference estimation block is used to obtain descending pilot frequency time slot signal Interference Estimation value;

Interference cancellation module, link to each other with described interference estimation block, be used for the Interference Estimation result of a last subframe descending pilot frequency time slot signal being carried out interference eliminated to current subframe signal, export the uplink pilot time slot signal of pure current subframe according to interference estimation block.

Preferably, described device further comprises:

Detection module, link to each other with described interference estimation block with described interference cancellation module respectively, be used for uplink pilot time slot signal to the current subframe of described interference cancellation module output and carry out uplink synchronous sequence SYNC_UL sign indicating number and detect, and notify described interference estimation block testing result.

Described interference estimation block comprises:

Memory module is used to store current subframe descending pilot frequency time slot signal Interference Estimation value;

Computing module is used to calculate current subframe descending pilot frequency time slot signal Interference Estimation value, and result of calculation is stored in the described memory module.

If described detection module does not detect the SYNC_UL sign indicating number in the uplink pilot time slot signal of current subframe, then notify described interference estimation block to calculate current subframe descending pilot frequency time slot signal Interference Estimation value;

If described detection sub-module detects at least one SYNC_UL sign indicating number in the uplink pilot time slot signal of current subframe, then notify described interference estimation block need not calculate current subframe descending pilot frequency time slot signal Interference Estimation value.

If the notice request that described interference estimation block is received calculates current subframe descending pilot frequency time slot signal Interference Estimation value, then described computing unit calculates by recursive fashion, and send result of calculation to described interference cancellation module, simultaneously result of calculation is stored in described memory cell;

Do not calculate current subframe descending pilot frequency time slot signal Interference Estimation value if the notice that described interference estimation block is received requires, then interference estimation block sends the last subframe descending pilot frequency time slot signal Interference Estimation value of storing in the described memory cell to described interference cancellation module.

By above technical scheme provided by the invention as can be seen, the present invention carries out interference eliminated according to the Interference Estimation value of last subframe to the current subframe signal that receives, with the signal after the interference eliminated as glitch-free purified signal.And the descending pilot frequency time slot signal Interference Estimation value of employed last subframe during current subframe interference eliminated is carried out the SYNC_UL sign indicating number by the purified signal to last subframe and is detected to determine.If last subframe does not detect the SYNC_UL signal, just last subframe is carried out the estimation that descending pilot frequency time slot signal disturbs; If last subframe has detected at least one SYNC_UL coded signal, just directly incite somebody to action again the Interference Estimation value of the down-bound pilot frequency signal Interference Estimation value of last subframe as last subframe.Such descending pilot frequency time slot interference estimation method can reduce the complexity of the calculating and the realization of Interference Estimation value effectively, has simplified the reflection owing to down-bound pilot frequency signal in the uplink pilot signal is produced the elimination processing procedure of disturbing.Like this, when receiving the uplink pilot time slot signal, just can directly carry out the SYNC_UL sign indicating number and detect, improve SYNC_UL and detected performance the uplink pilot time slot signal after the interference eliminated in the base station.

Simultaneously, in the estimation of the present invention to the interference of the reflection generation of down-bound pilot frequency signal,, parameter N um represents that the down-bound pilot frequency signal reflection produces the duration of disturbing by being set.This parameter provides space and flexibility for the present invention further improves SYNC_UL sign indicating number detection performance.Can determine simply, once that in the network planning this parameter values is to improve systematic function; Also can this parameter values directly be set, for example make Num=100 or Num=150 according to the experience of the network planning; Certainly, also can be directly simply this parameter be set to 256.Utilize the present invention, can reduce consumption greatly, improve the service in base station handling property BTS hardware and software resource.

Description of drawings

Fig. 1 is the physical channel signal form of TD-SCDMA system;

Fig. 2 is the process chart of DwPTS interference cancellation algorithm in the prior art;

Fig. 3 is the realization flow figure of an embodiment of the inventive method;

Fig. 4 is the theory diagram of an embodiment of apparatus of the present invention;

Fig. 5 is the theory diagram of another embodiment of apparatus of the present invention.

Embodiment

Core of the present invention is to simplify the processing procedure of eliminating the reflected signal of down-bound pilot frequency signal in this signal when base station reception uplink pilot time slot signal.For this reason, the present invention carries out interference eliminated according to the Interference Estimation value of the down-bound pilot frequency signal of last subframe to the current subframe signal that receives, with the signal after the interference eliminated as glitch-free purified signal.In order to obtain this purified signal effectively, and the calculating of reduction Interference Estimation value and the complexity of realization, the present invention carries out the SYNC_UL sign indicating number by the current subframe uplink pilot frequency time slot signal after elimination is disturbed and detects, and determines next subframe descending pilot frequency time slot signal Interference Estimation value according to testing result.If in the uplink pilot time slot signal of m subframe, do not detect the SYNC_UL sign indicating number, then calculate m subframe descending pilot frequency time slot signal Interference Estimation value by recursive fashion; If in the uplink pilot time slot signal of m subframe, detect at least one SYNC_UL sign indicating number, then no longer recomputate descending pilot frequency time slot signal Interference Estimation value, but with m-1 subframe descending pilot frequency time slot interference signal estimated value as m subframe descending pilot frequency time slot interference signal estimated value.If carried out the antenna correction in the m subframe, then with m-1 subframe descending pilot frequency time slot interference signal estimated value as m subframe descending pilot frequency time slot interference signal estimated value.

In order to make those skilled in the art person understand the present invention program better, the present invention is described in further detail below in conjunction with drawings and embodiments.

With reference to Fig. 3, Fig. 3 shows the realization flow of an embodiment of the inventive method, may further comprise the steps:

Step 301: the descending pilot frequency time slot signal Interference Estimation value of setting the 0th subframe is 0.

In the present invention, the elimination that down-bound pilot frequency signal in the current subframe is disturbed is with reference in the last subframe Interference Estimation value of down-bound pilot frequency signal to be carried out.Therefore, for the 1st subframe signal, can suppose that the descending pilot frequency time slot signal Interference Estimation value of its last subframe is 0.That is to say, not before the receiving uplink pilot signals, can think that the reflection interference of descending pilot frequency time slot signal is 0 in the base station.

Step 302: set the variable m=1 that represents the subframe sequence number.

Step 303: obtain m-1 subframe descending pilot frequency time slot signal Interference Estimation value.

Step 304: the uplink pilot time slot signal that obtains the m subframe of reception.

Step 305: carry out the interference elimination treatment process.

Calculate the uplink pilot time slot signal of m subframe according to following formula:

$\mathrm{mod}i\_\mathrm{value}\_1_m\left[\mathrm{ante}\right]\left[i\right]=\mathrm{inst}\_{\mathrm{value}}_m\left[\mathrm{ante}\right]\left[i\right]-e^{j{\mathrm{\θ}}_m}{\mathrm{av}}_{m-1}\left[\mathrm{ante}\right]\left[i\right],$

i＝1，2，...，Num；ante＝1，2，...，N；

Wherein, modi_value_1 _m[ante] [i] is i chip signal on the ante antenna after the descending pilot frequency time slot signal interference eliminated,

Inst_value _m[ante] [i] is the uplink pilot signal on ante the antenna of m subframe that receives;

Av _M-1[ante] [i] is the estimated value of down-bound pilot frequency signal to the interference of i chip on the m-1 subframe ante antenna;

θ _mThe phase place that adopts when launching for SYNC-DL sign indicating number in m subframe descending pilot frequency time slot signal;

Num is the scope that down-bound pilot frequency signal causes interference.

If Num＜256 also will be carried out following assignment and be calculated:

modi_value_1 _m[ante][i]＝inst_value _m[ante][i]，

i＝Num+1，...，256；ante＝1，2，...，N.

Through after the interference eliminated, export the uplink pilot time slot signal of pure m subframe.The SYNC_UL detection is carried out to this signal in the base station, can improve the detection performance of SYNC-UL.

Step 306: the m subframe uplink pilot frequency time slot signal after the output interference eliminated.

Step 307: the m subframe uplink pilot frequency time slot signal to output carries out the detection of SYNC_UL sign indicating number, promptly detects whether contain the SYNC_UL sign indicating number in this signal, also needs to detect this subframe simultaneously and whether has carried out the antenna correction.

In order to eliminate the interference of descending pilot frequency time slot signal effectively, need the correct size of estimating this interference value.In the present invention, determine the descending pilot frequency time slot Interference Estimation value used in next subframe interference cancellation process according to whether containing the SYNC_UL sign indicating number in the current subframe uplink pilot frequency time slot signal.

If do not detect the SYNC_UL sign indicating number and do not carry out the antenna correction, then enter step 308 in this subframe; If detect at least one SYNC_UL sign indicating number or carried out the antenna correction, then enter step 309 in this subframe.

Step 308: calculate m subframe descending pilot frequency time slot signal Interference Estimation value by recursive fashion.Concrete computational process will be described in detail later.

Step 309: m-1 subframe descending pilot frequency time slot interference signal estimated value as m subframe descending pilot frequency time slot interference signal estimated value, is promptly satisfied following equation:

av _m[ante][i]＝av _m-1[ante][i]，i＝1，2，.....，Num；ante＝1，2，....，N.

Because the environment relative fixed around the base station, the reflected signal of down-bound pilot frequency signal changes slowly.And continuously long-time each subframe all has the probability of SYNC-UL signal minimum.Therefore, the present invention only carries out the estimation of the interference of down-bound pilot frequency signal to the subframe that does not receive the SYNC-UL signal, just can follow the tracks of the variation of the reflected signal of down-bound pilot frequency signal fast enough.

After having determined m subframe descending pilot frequency time slot interference signal estimated value, enter step 310:

Step 310: the subframe sequence number is added 1, i.e. m=m+1.Then, return step 303, carry out the interference cancellation process of next subframe.

Mention in front,, then calculate m subframe descending pilot frequency time slot signal Interference Estimation value by recursive fashion if do not detect the SYNC_UL sign indicating number in the current subframe uplink pilot frequency time slot signal after interference eliminated.Can be expressed as follows:

${\mathrm{av}}_m\left[\mathrm{ante}\right]\left[i\right]=\frac{(P-1)\·{\mathrm{av}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]+e^{j(-{\mathrm{\θ}}_m)}\·\mathrm{inst}\_{\mathrm{value}}_m\left[\mathrm{ante}\right]\left[i\right]}{P},$

i＝1，2，...，Num，ante＝1，2，...，N；

Wherein, inst_value _m[ante] [i] is illustrated in i chip signal in the m subframe that receives on ante the antenna, comprises DwPTS reflected signal and other interference signals (noise);

θ _mThe phase place that adopts when launching for SYNC-DL sign indicating number in m subframe DwPTS;

The scope of the interference that the down-bound pilot frequency signal of representing Num causes, its span are 1～256, after the site of determining NodeB, can determine the concrete numerical value of Num during the network planning;

N is a number of antennas;

P is the forgetting factor of recurrence in average, P ∈ [0,1].

Usually, if the descending pilot frequency time slot signal reflection slowly changes, then get bigger P value; If the descending pilot frequency time slot signal reflection changes fast, then select less P value, so that follow the tracks of the situation of change of descending pilot frequency time slot signal reflection as quickly as possible, improve the accuracy of Interference Estimation.

Because the interference that down-bound pilot frequency signal causes only is present in the 1st～Num chip, therefore,, calculating inst_value though GP and UpPTS always have 256 chips _mDuring [ante] [i], only need to consider that the interference in 1～Num the chip gets final product.

As seen, utilize the present invention, only need the subframe signal that does not detect the SYNC_UL sign indicating number is carried out the descending pilot frequency time slot signal Interference Estimation, simplified the complexity of handling effectively, saved system hardware and software resource.

With reference to Fig. 4, Fig. 4 shows the theory diagram of an embodiment of apparatus of the present invention:

This device comprises: interference estimation block S2 and interference cancellation module S1.Wherein, interference estimation block S2 is used to obtain descending pilot frequency time slot signal Interference Estimation value; Interference cancellation module S1 links to each other with interference estimation block S2, be used for the Interference Estimation result of a last subframe descending pilot frequency time slot signal being carried out interference eliminated to current subframe signal, export the uplink pilot time slot signal of pure current subframe according to interference estimation block S2.

Interference estimation block S2 estimates descending pilot frequency time slot signal Interference Estimation value in the current subframe according to the uplink pilot time slot signal of the current subframe of interference cancellation module S1 output, and provide it to interference cancellation module S1, carry out descending pilot frequency time slot signal Interference Estimation value required in next subframe interference cancellation process as it.

At first, interference estimation block S2 carries out the detection of SYNC_UL sign indicating number to the m subframe uplink pilot frequency time slot signal of output, promptly detects whether contain the SYNC_UL sign indicating number in this signal, also needs to detect this subframe simultaneously and whether has carried out the antenna correction.

In order to eliminate the interference of descending pilot frequency time slot signal effectively, need the correct size of estimating this interference value.In the present invention, interference estimation block S2 can determine the descending pilot frequency time slot Interference Estimation value used in next subframe interference cancellation process according to whether containing the SYNC_UL sign indicating number in the current subframe uplink pilot frequency time slot signal.If detect at least one SYNC_UL sign indicating number or carried out the antenna correction, then can promptly satisfy following equation with m-1 subframe descending pilot frequency time slot interference signal estimated value as m subframe descending pilot frequency time slot interference signal estimated value in this subframe:

av _m[ante][i]＝av _m-1[ante][i]，i＝1，2，.....，Num；ante＝1，2，....，N.

If do not detect the SYNC_UL sign indicating number and do not carry out the antenna correction, then can calculate descending pilot frequency time slot signal Interference Estimation value according to following formula in this subframe:

${\mathrm{av}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]=\frac{(P-1)\·{\mathrm{av}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]+e^{j(-{\mathrm{\θ}}_m)}\·\mathrm{inst}\_{\mathrm{value}}_m\left[\mathrm{ante}\right]\left[i\right]}{P},$

i＝1，2，...，Num，ante＝1，2，...，N；

Wherein, inst_value _m[ante] [i] is illustrated in i chip signal in the m subframe that receives on ante the antenna, comprises DwPTS reflected signal and other interference signals (noise), inst_value _m[ante] [i] and av _m[ante] [i] is plural number.

In order further to simplify computational process, save system resource, can be earlier the uplink pilot time slot signal of the current subframe of interference cancellation module S1 output be carried out uplink synchronous sequence SYNC_UL sign indicating number and detect, determine according to testing result whether needs recomputate descending pilot frequency time slot signal Interference Estimation value.

Theory diagram with reference to another embodiment of apparatus of the present invention shown in Figure 5:

Compare with embodiment illustrated in fig. 4, in this embodiment, increased detection module S3, link to each other with interference estimation block S2 with interference cancellation module S1 respectively, be used for uplink pilot time slot signal to the current subframe of interference cancellation module S1 output and carry out uplink synchronous sequence SYNC_UL sign indicating number and detect, and notify interference estimation block S2 testing result.

Simultaneously, interference estimation block S2 comprises: memory module S22 and computing module S21.Wherein, memory module S22 is used to store current subframe descending pilot frequency time slot signal Interference Estimation value; Computing module S21 is used to calculate current subframe descending pilot frequency time slot signal Interference Estimation value, and result of calculation is stored among the memory module S22.

When carrying out the descending pilot frequency time slot signal Interference Estimation, at first the uplink pilot time slot signal of the current subframe of interference cancellation module S1 output is carried out uplink synchronous sequence SYNC_UL sign indicating number and detect by detection module S3.

If do not detect the SYNC_UL sign indicating number, then notify interference estimation block S2 to calculate current subframe descending pilot frequency time slot signal Interference Estimation value.At this moment, the computing module S21 of interference estimation block S2 can calculate the descending pilot frequency time slot signal Interference Estimation value of current subframe by recursive fashion, and this value is deposited among the memory module S22.

Such as, for the m subframe, can be expressed as follows:

${\mathrm{av}}_m\left[\mathrm{ante}\right]\left[i\right]=\frac{(P-1)\·{\mathrm{av}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]+e^{j(-{\mathrm{\θ}}_m)}\·\mathrm{inst}\_{\mathrm{value}}_m\left[\mathrm{ante}\right]\left[i\right]}{P},$

i＝1，2，...，Num，ante＝1，2，...，N；

Wherein, inst_value _m[ante] [i] is illustrated in i chip signal in the m subframe that receives on ante the antenna, comprises DwPTS reflected signal and other interference signals (noise), inst_value _m[ante] [i] and av _m[ante] [i] is plural number.

Interference estimation block S2 exports to interference cancellation module S1 with this value.

If detect at least one SYNC_UL sign indicating number, then notify interference estimation block S2 need not calculate current subframe descending pilot frequency time slot signal Interference Estimation value.At this moment, interference estimation block S2 takes out the last subframe descending pilot frequency time slot signal Interference Estimation value of its storage from memory module S22, and this value is exported to interference cancellation module S1.

Though described the present invention by embodiment, those of ordinary skills know, the present invention has many distortion and variation and do not break away from spirit of the present invention, wish that appended claim comprises these distortion and variation and do not break away from spirit of the present invention.

Claims (13)

1. eliminate the method that descending pilot frequency time slot signal disturbs for one kind, it is characterized in that described method comprises:

A, obtain m-1 subframe descending pilot frequency time slot signal Interference Estimation value, wherein, m＞=1;

B, m subframe uplink pilot frequency time slot signal is carried out interference eliminated, obtain the uplink pilot time slot signal of pure m subframe according to m-1 subframe descending pilot frequency time slot signal Interference Estimation value.

2. method according to claim 1 is characterized in that, described method further comprises:

The descending pilot frequency time slot signal Interference Estimation value of setting the 0th subframe is 0.

3. method according to claim 1 and 2 is characterized in that, the described step of obtaining m-1 subframe descending pilot frequency time slot signal Interference Estimation value comprises:

The uplink pilot time slot signal of the pure m-1 subframe that obtains is carried out uplink synchronous sequence SYNC_UL sign indicating number to be detected;

Determine m-1 subframe descending pilot frequency time slot signal Interference Estimation value according to testing result.

4. method according to claim 3 is characterized in that, describedly determines that according to testing result the step of m-1 subframe descending pilot frequency time slot signal Interference Estimation value comprises:

If in the uplink pilot time slot signal of described m-1 subframe, do not detect the SYNC_UL sign indicating number, then calculate m-1 subframe descending pilot frequency time slot signal Interference Estimation value by recursive fashion;

If in the uplink pilot time slot signal of m-1 subframe, detect at least one SYNC_UL sign indicating number, then with m-2 subframe descending pilot frequency time slot interference signal estimated value as m-1 subframe descending pilot frequency time slot interference signal estimated value.

5. method according to claim 4 is characterized in that, describedly estimates that by recursive fashion the step of m-1 subframe descending pilot frequency time slot signal Interference Estimation value is specially:

Estimate on each antenna descending pilot frequency time slot signal Interference Estimation value in each chip by following formula:

${\mathrm{av}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]=\frac{(P-1)\·{\mathrm{av}}_{m-2}\left[\mathrm{ante}\right]\left[i\right]+e^{j(-{\mathrm{\θ}}_{m-1})}\·\mathrm{inst}\_{\mathrm{value}}_{m-1}\left[\mathrm{ante}\right]\left[i\right]}{P},$

i＝1，2，...，Num，ante＝1，2，...，N；

Wherein, N is a number of antennas;

Num is the scope of the interference that causes of down-bound pilot frequency signal;

e ^{J (θ m-1)}In j be the unit of imaginary number, j ²=-1;

θ _M-1, the phase place that adopts when launching for SYNC-DL sign indicating number in m-1 subframe descending pilot frequency time slot signal;

Av _M-1[ante] [i] is the Interference Estimation value of m-1 subframe descending pilot frequency time slot signal at ante antenna i chip;

Inst_value _M-1[ante] [i] is i chip signal in the m-1 frame on ante the antenna that is received;

P is a forgetting factor.

6. method according to claim 3 is characterized in that, describedly determines that according to testing result the step of m-1 subframe descending pilot frequency time slot signal Interference Estimation value further comprises:

If carried out the antenna correction in the m-1 subframe, then with m-2 subframe descending pilot frequency time slot interference signal estimated value as m-1 subframe descending pilot frequency time slot interference signal estimated value.

7. method according to claim 3 is characterized in that, described step B is specially:

Calculate the uplink pilot time slot signal of m subframe according to following formula:

${\mathrm{mod}i\_\mathrm{value}\_1}_m\left[\mathrm{ante}\right]\left[i\right]={\mathrm{inst}\_\mathrm{value}}_m\left[\mathrm{ante}\right]\left[i\right]-e^{{\mathrm{j\θ}}_m}{\mathrm{av}}_{m-1}\left[\mathrm{ante}\right]\left[i\right],$

i＝1，2，...，Num；ante＝1，2，...，N；

Wherein, modi_value_1 _m[ante] [i] is i chip signal on ante antenna of m subframe after the descending pilot frequency time slot signal interference eliminated;

Inst_value _m[ante] [i] is i chip signal in the m subframe on the ante antenna that is received;

Av _M-1[ante] [i] is descending pilot frequency time slot signal Interference Estimation value in i chip on the ante antenna in the m-1 subframe;

θ _mThe phase place that adopts when launching for SYNC-DL sign indicating number in m subframe descending pilot frequency time slot signal;

Num is the scope that down-bound pilot frequency signal causes interference.

8. method according to claim 7 is characterized in that, described step B further comprises:

When Num＜256, carry out following assignment and calculate:

modi_value_1 _m[ante][i]＝inst_value _m[ante][i]，

i＝Num+1，...，256；ante＝1，2，...，N。

9. eliminate the device that descending pilot frequency time slot signal disturbs for one kind, it is characterized in that, comprising:

Interference estimation block is used to obtain descending pilot frequency time slot signal Interference Estimation value;

Interference cancellation module, link to each other with described interference estimation block, be used for the Interference Estimation result of a last subframe descending pilot frequency time slot signal being carried out interference eliminated to current subframe signal, export the uplink pilot time slot signal of pure current subframe according to interference estimation block.

10. device according to claim 9 is characterized in that, described device further comprises:

Detection module, link to each other with described interference estimation block with described interference cancellation module respectively, be used for uplink pilot time slot signal to the current subframe of described interference cancellation module output and carry out uplink synchronous sequence SYNC_UL sign indicating number and detect, and notify described interference estimation block testing result.

11. device according to claim 10 is characterized in that, described interference estimation block comprises:

Memory module is used to store current subframe descending pilot frequency time slot signal Interference Estimation value;

Computing module is used to calculate current subframe descending pilot frequency time slot signal Interference Estimation value, and result of calculation is stored in the described memory module.

12. device according to claim 11 is characterized in that,

If described detection module does not detect the SYNC_UL sign indicating number in the uplink pilot time slot signal of current subframe, then notify described interference estimation block to calculate current subframe descending pilot frequency time slot signal Interference Estimation value;

If described detection sub-module detects at least one SYNC_UL sign indicating number in the uplink pilot time slot signal of current subframe, then notify described interference estimation block need not calculate current subframe descending pilot frequency time slot signal Interference Estimation value.

13. device according to claim 12 is characterized in that,

If the notice request that described interference estimation block is received calculates current subframe descending pilot frequency time slot signal Interference Estimation value, then described computing unit calculates by recursive fashion, and send result of calculation to described interference cancellation module, simultaneously result of calculation is stored in described memory cell;

Do not calculate current subframe descending pilot frequency time slot signal Interference Estimation value if the notice that described interference estimation block is received requires, then interference estimation block sends the last subframe descending pilot frequency time slot signal Interference Estimation value of storing in the described memory cell to described interference cancellation module.