CN1874170A - United detection method for multiple cells in time division code division multiple access - Google Patents

Abstract

The invention discloses a multi-cell joint detection method of a time-slot code division multiple access system, comprising: performing multi-code set channel estimation on received signal data to obtain the channel estimation results of this cell and each adjacent cell; The channel estimation results of the channel estimation results and the channel estimation results of adjacent cells are sequentially intercepted corresponding to the channel estimation results of each user in the cell; according to the relative time delay difference between user signals in different cells, adjust the cell and/or each adjacent cell The channel estimation result of each user in the cell or the estimation result of the combined channel response; the joint detection is performed on the received data by using the estimation result of the combined channel response of each cell to obtain the detection data. The invention can suppress the multiple access interference of asynchronous co-frequency adjacent cells, and improve the system performance of the time-slot code division multiple access system in actual co-frequency networking.

Description

Multi-cell Joint Detection Method in Slotted Code Division Multiple Access System

technical field

The invention relates to a joint detection technology in the technical field of mobile communication, in particular to a multi-cell joint detection method of a time-slot code division multiple access system.

Background technique

In the CDMA (Code Division Multiple Access) mobile communication system, due to the certain correlation between the signals of each user, MAI (Multiple Access Interference) has become a main interference of the wideband CDMA system. The traditional signal separation method of CDMA system treats MAI as noise, and regards the signal separation of a single user as an independent process, that is, single user detection technology. This detection method leads to a severe degradation of the signal-to-noise ratio, limiting the capacity of the system. In fact, MAI contains a lot of information that can be used to improve the accuracy of signal separation methods, such as known user channel codes, channel estimates of each user, etc. Multi-user detection technology is a joint detection using these information. According to different processing methods for multiple access interference, multi-user detection technology can be divided into two types: interference cancellation and joint detection. Among them, the basic idea of interference cancellation technology is decision feedback. Firstly, part of the data is judged from the total received signal, and the signal corresponding to the data is reconstructed according to the data and the user spreading code, and then the duplicate signal is subtracted from the total received signal. Construct the signal, and iterate in this way. The joint detection technology refers to a signal separation technology that makes full use of multiple access interference and separates the signals of all users within one step.

In a CDMA system, joint detection technology can be used to eliminate multiple access interference and intersymbol interference for the received signal of the cell. TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) is a time-slotted CDMA system that adopts a joint detection scheme for multi-user signals in the cell.

In the TD-SCDMA system, the burst signal structure of a regular time slot is shown in Figure 1: the midamble (midamble, also called channel estimation code) in the middle of the burst signal is used for channel estimation, and the data blocks on both sides are used for Send business data.

The single-cell joint detection method utilizes the structural information (including spreading codes and channel responses) of the signals sent by all users in this cell, and treats the interference signals of other cells as time Gaussian white noise. Therefore, the single-cell joint detection algorithm It has a strong ability to suppress inter-symbol interference and multiple access interference in this cell, and can greatly improve system performance for single cell or inter-frequency CDMA systems.

However, in the case of co-frequency networking, there is strong mutual interference between the signals of adjacent cells of the same frequency, and the interference between adjacent cells of the same frequency has a very important impact on the performance of the system, especially in the At the junction of adjacent cells with the same frequency, the same-frequency interference is often the most important interference when there are multiple code channels for users in adjacent cells with the same frequency to work. At this time, the single-cell joint detection method will be helpless to the interference of the adjacent cells of the same frequency.

If the structure information of adjacent cells on the same frequency can be used to extend the joint detection technology from a single cell to multiple cells on the same frequency, the performance of the time-slotted CDMA system in the same-frequency networking will be greatly improved. In view of this, Chinese patent application 200410080196.6 provides a "multi-cell joint detection method in a time-slotted code division multiple access system". The code channels of each adjacent cell are grouped, and then the joint detection is performed by using the channel estimation results of each adjacent cell and the result of the code channel grouping. This joint detection scheme is used in the same-frequency multi-cell time-slot CDMA system, which can greatly suppress the multiple access interference of the same-frequency adjacent cells, and improve the system performance of the time-slot CDMA system when it works in the same-frequency adjacent cells. This technical solution is applicable to the situation that signals of users in different cells are synchronous or approximately synchronous or the relative time delay deviation is not large.

Usually, there is a relative time delay between signals of multiple cells of the same frequency. If only the interference with the same-frequency cell closest to the geographical location of the cell is considered, the relative delay will be relatively small, so the channel response windows of users in different cells are taken according to the cell to ensure that the main path is basically within the window, so The impact of relative delay can be ignored. However, in large-scale networking, the same-frequency interference of peripheral cells may also be considered; in hierarchical networking, the same-frequency interference between macro cells and micro-intervals must also be considered. For example, in the schematic diagram of the main path relationship between adjacent cells and users in this cell in the channel estimation results shown in Figure 2, adjacent cell 1 and this cell have a relatively small relative time delay ΔT ₁ Intercepting according to the method of this cell can also ensure that the main path is basically included in the result; while the adjacent cell 2 has a small relative time delay ΔT ₂ with this cell, for this kind of co-channel interference, there is a relatively large relative delay between multi-cell signals. If the channel estimation results of each user in the adjacent cell are still intercepted according to the method of the local cell, the main path of the user will be intercepted by other users in the cell, and the interference of the same-frequency adjacent cells cannot be eliminated correctly, resulting in Severe deterioration of system performance.

Contents of the invention

The purpose of the present invention is to provide a multi-cell joint detection method of a time-slot code division multiple access system, to overcome the shortcomings of the existing technology that cannot adapt to the situation of relatively large relative time delay between signals of the same frequency multi-cell, and correctly eliminate the same frequency adjacent Cell interference, improve the system performance of the slotted CDMA system when working in the same frequency adjacent cells with relatively large relative time delay.

For this reason, the present invention provides following technical scheme:

A multi-cell joint detection method of a time-slot code division multiple access system, comprising the steps of:

A. Carry out multi-code set channel estimation on the received signal data, and obtain the channel estimation results of this cell and each adjacent cell;

B. Intercepting the channel estimation results corresponding to each user in the cell in turn from the channel estimation results of this cell and the channel estimation results of adjacent cells;

C. Adjusting the channel estimation results of each user in the current cell and/or each adjacent cell according to the relative time delay difference between user signals in different cells;

D. Calculate the estimated result of the combined channel response of this cell and the adjacent cell according to the spreading code of each user and the corresponding adjusted channel estimation result;

E. Perform joint detection on the received data by using the estimation results of the combined channel response of each cell to obtain detection data.

A multi-cell joint detection method of a time-slot code division multiple access system, comprising the steps of:

A', performing multi-code set channel estimation on the received signal data, and obtaining the channel estimation results of this cell and each adjacent cell;

B', sequentially intercepting channel estimation results corresponding to each user in the cell from the channel estimation results of this cell and the channel estimation results of adjacent cells;

C', according to each user's spreading code and the corresponding channel estimation result, calculate the estimated result of the combined channel response of this cell and the adjacent cell;

D', adjusting the estimated result of the combined channel response of each user in the current cell and the adjacent cell according to the relative time delay difference between user signals in different cells;

E′. Perform joint detection on the received data by using the adjusted estimation result of the combined channel response to obtain detection data.

In the step B and step B', the channel estimation results of each user are intercepted according to the following steps:

b1. Setting the total length Ln of the channel estimation results of each cell;

b2. Obtain the relative time delay difference ΔT _n between each adjacent cell and the user signal of this cell, and round the relative time delay difference ΔT _n to obtain the standard time delay difference ΔT′ _n ;

b3. Intercepting the channel estimation results of each user in the cell sequentially from the first chip of the total channel estimation result in the cell;

b4. If the signal of the neighboring cell is lagging behind that of the current cell, cyclically intercept the channel estimation result of each user in the neighboring cell from the _ΔT'n +1 chip of the total channel estimation result of the neighboring cell;

b5. If the signal of the adjacent cell is ahead of the current cell, the channel estimation result of each user in the adjacent cell is cyclically intercepted from the Ln-ΔT' _n +1 chip of the total channel estimation result of the adjacent cell .

Optionally, the operation of rounding the relative delay difference ΔT _n is specifically:

The relative delay difference ΔT _n is rounded down, or up, or customized.

Described step C specifically comprises:

C1, setting the length of the channel estimation result of the user in this cell is W1, the length of the channel estimation result of the adjacent cell user is W2; the length of the spreading code is Q;

C2. Extend the channel estimation results of each user in the cell in the following manner:

Before the channel estimation result of each user in this cell, extend l1 code chips with 0 of predetermined length, if there is no adjacent cell signal ahead of the signal of this cell, then do not extend that l1=0; afterward extend l2 code chips with 0 of predetermined length slice, if there is no adjacent cell signal lagging behind the local cell signal, then no extension, that is, l2=0;

C3. When W1+l2≥W2, expand the channel estimation results of each user in each adjacent cell in the following manner:

(1) When the adjacent cell signal lags behind this cell,

If mod(ΔT′ _n , Q)≤l2+(W1-W2), then extend l1+mod(ΔT′ _n , Q) code chips set to 0 before the channel estimation results of each user in the neighboring cell, and extend l2+( W1-W2)-mod(ΔT′ _n , Q) chips set to 0;

If mod(ΔT′ _n , Q)>l2+(W1-W2) and Q-mod(ΔT′ _n , Q)≤l1, then extend l1-(Q-mod(ΔT′ _n , Q)) 0-set chips, after the result, l2+(W1-W2)+(Q-mod(ΔT′ _n , Q)) 0-set chips are extended;

If mod(ΔT′ _n , Q)>l2+(W1-W2) and Q-mod(ΔT′ _n , Q)>l1, then when mod(ΔT′ _n , Q)≤l2+W1, each Extend l1+mod(ΔT′ _n , Q) chips set to 0 before the user channel estimation result, and mod(ΔT′ _n , Q)-(l2+(W1-W2)) chips after removing the result; when Q- When mod(ΔT′ _n , Q)≤l1+W2, remove the first (Q-mod(ΔT′ _n , Q))-l1 chips of the channel estimation results of each user in the adjacent cell, and then extend the result by l2+(W1-W2 )+(Q-mod(ΔT′ _n , Q)) chips set to 0; when mod(ΔT′ _n , Q)＞l2+W1 and Q-mod(ΔT′ _n , Q)＞l1+W2 , the user channel estimation result consists of a chip with a length of W1+l1+l2 and all 0s;

(2) When the adjacent cell signal is ahead of the own cell,

If mod(ΔT′ _n , Q)≤l1, extend l1-mod(ΔT′ _n , Q) code chips set to 0 before the channel estimation results of each user in the neighboring cell, and then extend l2+(W1-W2)+ mod(ΔT′ _n , Q) chips set to 0;

If mod(ΔT′ _n , Q)>l1 and Q-mod(ΔT′ _n , Q)≤l2+(W1-W2), then extend l1+(Q-mod(ΔT′ _n , Q)) chips set to 0, and after the result, l2+(W1-W2)-(Q-mod(ΔT′ _n , Q)) chips set to 0 are extended;

If mod(ΔT′ _n , Q)>l1 and Q-mod(ΔT′ _n , Q)>l2+(W1-W2), then when mod(ΔT′ _n , Q)≤l1+W2, remove all The first mod(ΔT′ _n , Q)-l1 chips of the user channel estimation result, after which the result is extended with l2+(W1-W2)+mod(ΔT′ _n , Q) chips set to 0; when Q-mod( When ΔT′ _n , Q)≤l2+W1, extend l1+(Q-mod(ΔT′ _n , Q)) code chips set to 0 before the channel estimation results of each user in the neighboring cell, and remove the result (Q-mod( ΔT′ _n , Q))-(l2+(W1-W2)) chips; when mod(ΔT′ _n , Q)>l1+W2 and Q-mod(ΔT′ _n , Q)>l2+W1, The user channel estimation result consists of a chip with a length of W1+l1+l2 and all 0s;

C4. When W1+l2<W2, expand the channel estimation results of each user in each adjacent cell in the following manner:

(1) When the adjacent cell signal lags behind this cell,

If Q-mod(ΔT′ _n , Q)≤l1, then extend l1-(Q-mod(ΔT′ _n , Q)) chips set to 0 before the channel estimation result of each user in the neighboring cell; if Q-mod (ΔT′ _n , Q)≥(W2-(W1+l2)), then extend (Q-mod(ΔT′ _n , Q))-(W2-(W1+l2)) zero-set codes after the result slice, if Q-mod(ΔT′ _n , Q)<(W2-(W1+l2)), then after removing the result (W2-(W1+l2))-(Q-mod(ΔT′ _n , Q)) chips;

If Q-mod(ΔT′ _n , Q)>l1, then extend l1+mod(ΔT′ _n , Q) chips set to 0 before the channel estimation result of each user in the neighboring cell; if mod(ΔT′ _n , Q )≤W1+l2, then remove mod(ΔT′ _n , Q)+(W2-(W1+l2)) chips, if mod(ΔT′ _n , Q)>W1+l2, then the user channel estimation The result will consist of a chip of all 0s of length W1+l1+l2, regardless of the previous extension;

Or, if Q-mod(ΔT′ _n , Q)>l1 and Q-mod(ΔT′ _n , Q)≤l1+W2, remove the previous Q-mod(ΔT′ _n , Q)-l1 chips; if Q-mod(ΔT′ _n , Q)≥(W2-(W1+l2)), the result is post-extended (Q-mod(ΔT′ _n , Q))-(W2- (W1+l2)) chips set to 0; if Q-mod(ΔT′ _n , Q)<(W2-(W1+l2)), then after removing the result (W2-(W1+l2))-( Q-mod(ΔT′ _n , Q)) chips; if Q-mod(ΔT′ _n , Q)>l1+W2, the user channel estimation result consists of a length of W1+l1+l2 all 0 Chip composition;

(2) When the adjacent cell signal is ahead of the own cell,

If mod(ΔT′ _n , Q)≤l1, extend l1-mod(ΔT′ _n , Q) code chips set to 0 before the channel estimation results of each user in the neighboring cell; if mod(ΔT′ _n , Q)≥ (W2-(W1+l2)), then extend mod(ΔT′ _n , Q)-(W2-(W1+l2)) chips set to 0 after the result, if mod(ΔT′ _n , Q)< (W2-(W1+l2)), after removing the result (W2-(W1+l2))-mod(ΔT′ _n , Q) chips;

If mod(ΔT′ _n , Q)>l1 and mod(ΔT′ _n , Q)≤l1+W2, remove the previous mod(ΔT′ _n , Q)-l1 chips of the channel estimation results of each user in the neighboring cell; If mod(ΔT′ _n , Q)≥(W2-(W1+l2)), then the result is post-extended mod(ΔT′ _n , Q)-(W2-(W1+l2)) chips set to 0; if mod(ΔT′ _n , Q)<(W2-(W1+l2)), then remove the result (W2-(W1+l2))-mod(ΔT′ _n , Q) chips; if mod(ΔT′ _n , Q)>l1+W2, then the user channel estimation result consists of a chip with a length of W1+l1+l2 and all 0s;

Or, if mod(ΔT′ _n , Q)>l1, then extend l1+Q-mod(ΔT′ _n , Q) chips set to 0 before the channel estimation results of each user in the neighboring cell; if Q-mod(ΔT ′ _n , Q)≤W1+l2, Q-mod(ΔT′ _n , Q)+(W2-(W1+l2)) chips after removal; if Q-mod(ΔT′ _n , Q)＞W1+ l2, then the user channel estimation result will consist of a chip with a length of W1+l1+l2 and all 0s, regardless of the previous extension.

Described step D ' specifically comprises:

D1', setting the length of the estimated result of the combined channel response of the user in this cell is W3, the length of the estimated result of the combined channel response of the adjacent cell user is W4; the length of the spreading code is Q;

D2', expand the estimated result of the combined channel response of each user in the cell in the following manner:

Before the estimation result of the combined channel response of each user in this cell, extend a predetermined length of l3 code chips set to 0, if no adjacent cell signal is ahead of the signal of this cell, then do not extend, that is, l3=0; then extend a predetermined length of l4 For the chips set to 0, if there is no adjacent cell signal lagging behind the local cell signal, it will not be extended, that is, l4=0;

D3', when W3+l4≥W4, expand the estimated result of each user combined channel response of each adjacent cell in the following manner:

(1) When the adjacent cell signal lags behind this cell,

If mod(ΔT′ _n , Q)≤l4+(W3-W4), then extend l3+mod(ΔT′ _n , Q) chips with 0 before the estimated result of combined channel response of each user in the adjacent cell, and after the result Extend l4+(W3-W4)-mod(ΔT′ _n , Q) chips set to 0;

If mod(ΔT′ _n , Q)>l4+(W3-W4) and Q-mod(ΔT′ _n , Q)≤l3, then extend l3-(Q-mod (ΔT′ _n , Q)) 0-set chips, and after the result, l4+(W3-W4)+(Q-mod(ΔT′ _n , Q)) 0-set chips are extended;

If mod(ΔT′ _n , Q)>l4+(W3-W4) and Q-mod(ΔT′ _n , Q)>l3, then extend l3+mod(ΔT′ _n , Q) chips set to 0, after removing the result mod(ΔT′ _n , Q)-(l4+(W3-W4)) chips; or remove the former ( Q-mod(ΔT′ _n , Q))-l3 chips, after the result, expand l4+(W3-W4)+(Q-mod(ΔT′ _n , Q)) 0-set chips;

(2) When the adjacent cell signal is ahead of the own cell,

If mod(ΔT′ _n , Q)≤l3, then extend l3-mod(ΔT′ _n , Q) chips set to 0 before the estimated result of combined channel response of each user in the adjacent cell, and then extend l4+(W3- W4)+mod(ΔT′ _n , Q) chips set to 0;

If mod(ΔT′ _n , Q)>l3 and Q-mod(ΔT′ _n , Q)≤l4+(W3-W4), then extend l3+(Q-mod( ΔT′ _n , Q)) chips set to 0, and after the result, l4+(W3-W4)-(Q-mod(ΔT′ _n , Q)) chips set to 0 are extended;

If mod(ΔT′ _n , Q)>l3 and Q-mod(ΔT′ _n , Q)>l4+(W3-W4), remove the former mod(ΔT′ _n , Q)-l3 chips, after the result, extend l4+(W3-W4)+mod(ΔT′ _n , Q) chips set to 0; or extend l3+(Q -mod(ΔT′ _n , Q)) chips set to 0, after removing the result (Q-mod(ΔT′ _n , Q))-(l4+(W3-W4)) chips;

D4' When W3+l4<W4, expand the estimated results of the combined channel response of each user in each adjacent cell in the following manner:

(1) When the adjacent cell signal lags behind this cell,

If Q-mod(ΔT′ _n , Q)≤l3, then extend l3-(Q-mod(ΔT′ _n , Q)) chips set to 0 before the estimated result of combined channel response of each user in the adjacent cell; if Q-mod(ΔT′ _n , Q)≥(W4-(W3+l4)), extend (Q-mod(ΔT′ _n ,Q))-(W4-(W3+l4)) after the result and set 0 chip, if Q-mod(ΔT′ _n , Q)<(W4-(W3+l4)), after removing the result (W4-(W3+l4))-(Q-mod(ΔT′ _n , Q) ) chips;

If Q-mod(ΔT′ _n , Q)>l3, then extend l3+mod(ΔT′ _n , Q) chips set to 0 before the estimated result of combined channel response of each user in the adjacent cell, and after removing the result mod( ΔT′ _n , Q)+(W4-(W3+l4)) chips;

Or, if Q-mod (ΔT′ _n , Q)>l3, remove the first Q-mod (ΔT′ _n , Q)-l3 chips of the estimated result of the combined channel response of each user in the adjacent cell; if Q-mod( _{If _} Q-mod(ΔT′ _n , Q)<(W4-(W3+l4)), after removing the result (W4-(W3+l4))-(Q-mod(ΔT′ _n , Q)) chips;

(2) When the adjacent cell signal is ahead of the own cell,

If mod(ΔT′ _n , Q)≤l3, extend l3-mod(ΔT′ _n , Q) chips set to 0 before the estimated result of combined channel response of each user in the adjacent cell; if mod(ΔT′ _n , Q )≥(W4-(W3+l4)), after the result, extend mod(ΔT′ _n , Q)-(W4-(W3+l4)) chips set to 0, if mod(ΔT′ _n , Q)< (W4-(W3+l4)), after removing the result (W4-(W3+l4))-mod(ΔT′ _n , Q) chips;

If mod(ΔT′ _n , Q)>l3, remove the first mod(ΔT′ _n , Q)-l3 code chips of the estimated result of the combined channel response of each user in the adjacent cell; if mod(ΔT′ _n , Q)≥( W4-(W3+l4)), extend mod(ΔT′ _n , Q)-(W4-(W3+l4)) chips set to 0 after the result, if mod(ΔT′ _n , Q)<(W4 -(W3+l4)), after removing the result (W4-(W3+l4))-mod(ΔT′ _n , Q) chips;

Or, if mod(ΔT′ _n , Q)>l3, extend l3+Q-mod(ΔT′ _n , Q) chips set to 0 before the estimated result of combined channel response of each user in the adjacent cell; after removing the result, Q - mod(ΔT' _n , Q)+(W4-(W3+14)) chips.

The estimated result of the combined channel response of each user in the local cell and the neighboring cell is b=Ch, where C is the spreading code corresponding to a code channel of a user in the local cell or the neighboring cell, and  is the convolution operator, h is the channel estimation result of the user.

Preferably, steps between step B and step D are also included:

The code channels of each adjacent cell are grouped.

Preferably, further steps are included between step B' and step D':

The code channels of each adjacent cell are grouped.

Optionally, the code channels of each adjacent cell are grouped in the following manner:

grouping the code channels of each adjacent cell based on the cell to which the code channel belongs; and/or

grouping code channels of neighboring cells based on code channel power or amplitude; and/or

The code channels of each neighboring cell are grouped based on the code channel correlation.

As can be seen from the technical solutions provided by the present invention above, the present invention aims at the situation that there is a relative time delay between the signals of the same frequency and multiple cells in the CDMA system, and uses the relative time delay information between the cells to adjust the channel response of each user in different cells. The process can be flexibly performed before calculating the estimated result of the combined channel response of the local cell and the neighboring cell, or after obtaining the estimated result of the combined channel response of the local cell and the neighboring cell; and then using the adjusted channel response to realize multiple Cell joint detection, thereby avoiding the detection error caused by the user's main path going out of the window in the cell with a relatively large relative delay, and greatly suppressing the relative delay, especially the multiple access of the same frequency adjacent cells when the delay is large Interference effectively improves the system performance of the time-slotted CDMA system in actual co-frequency networking.

Description of drawings

Fig. 1 is a schematic diagram of the TD-SCDMA service time slot burst structure;

Fig. 2 is a schematic diagram of the main path relationship between adjacent cells and user channel estimation results in this cell;

Fig. 3 is the realization flowchart of the inventive method;

Fig. 4a to Fig. 41 are schematic diagrams of adjusting channel estimation results of adjacent cell users in different situations;

Fig. 5 is a schematic diagram of the positional relationship of channel estimation results of different cells.

Detailed ways

The core of the present invention is to aim at the situation that there is a relative time delay between the signals of the adjacent cells of the same frequency. Relative to the time delay difference, adjust the channel estimation results of each user intercepted by the system from the channel estimation results of each cell. The channel estimation results of each user in this cell and/or each adjacent cell can be adjusted first according to the relative delay value, and then the estimated result of the combined channel response of this cell and the adjacent cell can be calculated according to the adjusted channel estimation result; First calculate the estimated result of the combined channel response of the local cell and the adjacent cell, and then adjust the estimated result of the combined channel response according to the relative time delay value. In this way, it is avoided to introduce signals of other users in the same cell into the channel estimation results of each user, and then use the obtained combined channel estimation results to perform multi-cell joint detection on the received data to obtain detection data.

In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

The realization process of the inventive method is as shown in Figure 3, comprises the following steps:

Step 301: multi-cell channel estimation: perform multi-code set channel estimation on the received signal data, and obtain channel estimation results of the current cell and neighboring cells.

The channel estimation codes of multiple co-frequency cells correspond to the channel estimation code signals of multiple code sets, and the channel estimation results of multiple co-frequency adjacent cells can be obtained by using the multi-code set channel estimation method.

In view of the fact that there are multi-code set channel estimation code response signals when multiple cells on the same frequency work, the channel estimation results of multiple cells can be obtained by using the multi-code set joint channel iterative estimation method based on finite time position judgment feedback processing. The specific process is as follows:

The result of single-code set channel estimation is subjected to finite-time judgment processing, and only a limited number of taps with strong signal responses are reserved, thereby recovering the interference signal of other code sets, and canceling the interference signal, and obtaining the net signal of each code set, Then perform single-code-set channel estimation on the net signals of each code set, repeat the above processing until the number of iterations is reached, and output the channel estimation result.

The optimized multi-code set channel estimation method can also be used to extract the maximum interference tap from the single code set channel estimation result, and directly perform the iterative operation of interference recovery and interference cancellation, so as to obtain the channel estimation results of multiple cells.

Step 302: sequentially intercept channel estimation results corresponding to each user in the cell from the channel estimation results of the current cell and the channel estimation results of neighboring cells.

Step 303: Adjust the channel estimation result or the combined channel response estimation result of the current cell and/or each adjacent cell according to the relative delay difference between user signals in different cells.

Through this adjustment, the channel estimation results of the adjacent cell users and the channel estimation results of the users in this cell, or the estimation results of the combined channel response of the adjacent cell users and the estimated results of the combined channel response of the users in the local cell are reflected in time. Correct sequence relationship, and avoid introducing signals of other users in the same cell into the channel estimation results of each user or the combined channel response estimation results, so as to ensure that the interference of adjacent cells can be correctly eliminated during joint detection.

The specific adjustment method will be described in detail later.

Step 304: Perform joint detection on the adjusted channel estimation results of each cell to obtain detection data.

In order to reduce the complexity of joint detection, before performing joint detection on the adjusted channel estimation results of each cell, the code channels of each adjacent cell can be grouped first, and then the adjusted channel estimation results of this cell and the code channel estimation results of adjacent cells grouped together for joint detection.

Channels can be grouped in the following ways:

(1) Grouping method based on the cell to which the code channel belongs: if there are several same-frequency cells, several groups are formed, and the code channels in each group only include the code channel of the cell.

(2) Grouping method based on code channel power or amplitude: the channel response obtained from the multi-cell channel estimation results, or the output results of each code channel matched filter, can estimate the power or amplitude of each code channel signal; then, according to the power Or the strength of the amplitude to group.

(3) Grouping method based on code channel correlation: first estimate the correlation between each code channel in the multi-cell signal, and group all code channels according to the strength of the correlation; the correlation for multiple code channels can be The mean, maximum, or minimum value of the correlation.

(4) A hybrid method based on the above method, or other grouping methods.

The joint detection method may be an interference cancellation method, or a joint detection method of linear block equalization, or a mixed method of the two. For example, the joint detection method of linear block equalization can be used in each group, and the method of interference cancellation can be used between groups of different code channels.

The above-mentioned code channels participating in code channel grouping and joint detection may be pre-allocated code channels of each adjacent cell;

When adjacent cells of the same frequency are working, a large number of code channels are allocated to multiple cells. Therefore, it may also be those activated code channels reserved after activation detection processing for all code channels of each adjacent cell.

In the method of the present invention, in order to avoid the detection error caused by the main path of the cell user going out of the window under various relative time delay situations, two adjustment methods can be used:

(1) After obtaining the channel estimation results of this cell and each adjacent cell, first adjust the channel estimation results of each user, and then calculate the estimation result of its combined channel response according to the adjusted channel estimation results of each user;

(2) After obtaining the channel estimation results of the local cell and each adjacent cell, first calculate the estimation result of the combined channel response of each user according to the result, and then adjust the obtained estimation result of the combined channel response of each user.

These two adjustment methods are similar and have similar effects.

The following takes the (1) method as an example to describe its adjustment process in detail.

Assuming that the total length of the channel estimation results of each cell is Ln, the relative delay difference between the adjacent cell and the user signal of this cell is ΔT _n , and the standard delay difference ΔT′ _n is obtained by rounding it up

First, according to the relative delay difference between user signals in different cells, the channel estimation results corresponding to each user in the cell are sequentially intercepted from the channel estimation results of the current cell and the channel estimation results of adjacent cells.

For this cell, the channel estimation result of each user is cyclically intercepted from the first chip of the total channel estimation result of this cell, and the interception length is W1.

If the signal of the adjacent cell is behind the current cell, it will be cyclically intercepted from the ΔT′ _n + 1th chip of the total channel estimation result of the adjacent cell; if the signal of the adjacent cell is ahead of the current cell, the total Ln-ΔT′ _n +1th chip of the channel estimation result is cyclically intercepted. The interception length is W2.

Let the length of the spreading code be 0, extend the channel estimation results of each user in this cell: extend a predetermined length l1 code chips set to 0 before the channel estimation results of each user in this cell, if no adjacent cell signal is ahead of this cell signal, then No extension, i.e. l1=0; extend the preset length l2 code chips set to 0 later, if no adjacent cell signal lags behind the signal of this cell, then no extension, i.e. l2=0;

Based on the channel estimation results of each user in the local cell, when the interception length W1≠W2 and the forward and backward extension length l1≠l2 of the local cell, there are various adjustments to neighboring cells, which will be explained separately below.

4a, 4b, 4c, 4d, 4e, 4f respectively show various adjustment modes in the case of W1+l2≥W2.

Referring to Figure 4a, assuming W1=14chip, W2=16chip, l1=4chip, l2=6chip, Q=8chip, ΔT′ _n =3chip and the adjacent cell signal lags behind this cell, then the channel estimation results of each user in the adjacent cell are required The front extension is 11+mod(ΔT′ _n , Q)=7 0-set chips, and the back extension is 12+(W1-W2)-mod(ΔT′ _n , Q)=1 0-set chip.

Among them, S01 is the adjusted user channel estimation result of the current cell; S1 is the adjusted adjacent cell user channel estimation result; S1' is the adjusted adjacent cell user channel estimation result.

Referring to Figure 4b, assuming W1=14chip, W2=16chip, l1=6chip, l2=4chip, Q=8chip, ΔT′ _n =5chip and the adjacent cell signal lags behind this cell, then the channel estimation results of each user in the adjacent cell are required Pre-expansion l1-(Q-mod(ΔT′ _n , Q))=3 chips set to 0, resulting in post-expansion l2+(W1-W2)+(Q-mod(ΔT′ _n ,Q))=5 Chip set to 0.

Among them, S02 is the adjusted user channel estimation result of the current cell; S2 is the adjusted adjacent cell user channel estimation result; S2' is the adjusted adjacent cell user channel estimation result.

Referring to Fig. 4c, suppose W1=14chip, W2=16chip, l1=2chip, l2=4chip, Q=8chip, ΔT' _n =5chip and the signal of the neighboring cell is behind the current cell. Wherein, S03 is the adjusted channel estimation result of the user in the cell.

Since mod(ΔT′ _n , Q)<l2+W1, extend l1+mod(ΔT′ _n , Q)=7 code chips set to 0 before the channel estimation results of each user in the neighboring cell, and mod(ΔT ' _n , Q)-(l2+(W1-W2))=3 chips. The adjusted channel estimation result of the adjacent cell users is S31'.

Because Q-mod(ΔT′ _n , Q)<l1+W2, remove the first (Q-mod(ΔT′ _n , Q))-l1=1 chip of the channel estimation results of each user in the neighboring cell, and then expand the result l2+(W1-W2)+(Q-mod(ΔT′ _n , Q))=5 chips with 0 set. The adjusted channel estimation result of the adjacent cell users is S32'.

Suppose W1=2chip, W2=2chip, l1=1chip, l2=1chip, Q=8chip, ΔT′ _n =4chip and the signal of the adjacent cell is behind the current cell. Wherein, S033 is the adjusted channel estimation result of the user in the cell.

At this time, because mod(ΔT′ _n , Q)>l2+W1 and Q-mod(ΔT′ _n , Q)>l1+W2, the user channel estimation result will be composed of a length W1+l1+l2=4 A chip composed of all 0s. S33 is the channel estimation result of the adjacent cell users before adjustment, and S33' is the adjusted channel estimation result of the adjacent cell users.

Referring to Figure 4d, assuming W1=14chip, W2=16chip, l1=4chip, l2=6chip, Q=8chip, ΔT′ _n =3chip and the adjacent cell signal is ahead of this cell, then the channel estimation results of each user in the adjacent cell are required Pre-spread l1-mod(ΔT′ _n , Q)=1 chip with 0 set, and extend later with l2+(W1-W2)+mod(ΔT′ _n , Q)=7 chips with 0 set.

Wherein, S04 is the adjusted user channel estimation result of the current cell; S4 is the adjusted adjacent cell user channel estimation result; S4' is the adjusted adjacent cell user channel estimation result.

Referring to Figure 4e, assuming W1=14chip, W2=16chip, l1=4chip, l2=6chip, Q=8chip, ΔT' _n =5chip and the adjacent cell signal is ahead of this cell, then the channel estimation results of each user in the adjacent cell are required Pre-expansion l1+(Q-mod(ΔT′ _n , Q))=7 chips set to 0, after extension l2+(W1-W2)-(Q-mod(ΔT′ _n ,Q))=1 chip set to 0 chips.

Wherein, S05 is the adjusted user channel estimation result of the local cell; S5 is the adjusted adjacent cell user channel estimation result; S5' is the adjusted adjacent cell user channel estimation result.

Referring to Fig. 4f, suppose W1=14chip, W2=16chip, l1=2chip, l2=4chip, Q=8chip, ΔT' _n =5chip and the signal of the adjacent cell is ahead of the own cell. Wherein, S06 is the adjusted channel estimation result of the user in the cell.

Because mod(ΔT′ _n , Q)<l1+W2, remove the front mod(ΔT′ _n , Q)-l1=3 chips of the channel estimation results of each user in the neighboring cell, and then extend the result by l2+(W1-W2) +mod(ΔT′ _n , Q)=7 chips set to 0. The adjusted channel estimation result of the adjacent cell users is S61'.

Since Q-mod(ΔT′ _n , Q)<l2+W1, extend l1+(Q-mod(ΔT′ _n ,Q))=5 chips set to 0 before the channel estimation results of each user in the neighboring cell, and remove (Q-mod(ΔT' _n , Q))-(l2+(W1-W2))=1 chip after the result. The adjusted channel estimation result of the adjacent cell users is S62'.

Suppose W1=2chip, W2=2chip, l1=1chip, l2=1chip, Q=8chip, ΔT′ _n =4chip and the signal of the adjacent cell is ahead of the own cell. Wherein, S066 is the adjusted channel estimation result of the user in the cell.

At this time, because mod(ΔT′ _n , Q)>l1+W2 and Q-mod(ΔT′ _n , Q)>l2+W1, the user channel estimation result will be composed of a length W1+l1+l2=4 A chip composed of all 0s. S66 is the channel estimation result of the adjacent cell users before adjustment, and S66' is the adjusted channel estimation result of the adjacent cell users.

4g, 4h, 4i, 4j, 4k, 4l respectively show various adjustment modes under the condition of W1+l2<W2.

Referring to Fig. 4g, it is assumed that W1=12chip, W2=16chip, l1=6chip, l2=2chip, Q=8chip, and the signal of the neighboring cell is lagging behind that of the current cell. S07 is the adjusted channel estimation result of the user in the cell.

When ΔT′ _n =5chip, it is necessary to extend l1-(Q-mod(ΔT′ _n , Q))=3 chips set to 0 before the channel estimation results of each user in the neighboring cell, and extend (Q-mod (ΔT′ _n , Q))-(W2-(W1+12))=1 chip set to 0. Wherein, S71 adjusts the channel estimation result of the user in the adjacent cell before; S71' is the channel estimation result of the user in the adjacent cell after adjustment.

When ΔT′ _n =7 chips, it is necessary to extend l1-(Q-mod(ΔT′ _n , Q))=5 chips with 0 before the channel estimation results of each user in the neighboring cell, and after removing the result (W2-(W1 +12))-(Q-mod(ΔT' _n , Q))=1 chip. Wherein, S72 adjusts the channel estimation result of the user in the adjacent cell before; S72' is the channel estimation result of the user in the adjacent cell after adjustment.

Referring to Fig. 4h, suppose W1 = 4chip, W2 = 10chip, l1 = 2chip, l2 = 2chip, Q = 8chip, and the signal of the adjacent cell is behind the current cell. S08 is the adjusted channel estimation result of the users in the cell.

When ΔT′ _n =4chip, it is necessary to extend l1+mod(ΔT′ _n , Q)=6 chips set to 0 before the channel estimation results of each user in the neighboring cell, and after removing the result mod(ΔT′ _n ,Q)+ (W2-(W1+12))=8 chips. Wherein, S81 is the user channel estimation result of the adjacent cell before adjustment; S81' is the user channel estimation result of the adjacent cell after adjustment.

When ΔT′ _n =7chip, the user channel estimation result will consist of a chip with a length of W1+l1+l2=8 and all 0s. Wherein, S82 is the user channel estimation result of the adjacent cell before adjustment; S82' is the user channel estimation result of the adjacent cell after adjustment, that is, all 0 chips with a length of 8 chips.

Referring to Fig. 4i, suppose W1=4chip, W2=10chip, l1=2chip, l2=2chip, Q=8chip, and the signal of the adjacent cell is behind the current cell. S09 is the adjusted channel estimation result of the user in the cell.

When ΔT′ _n =3chip, it is necessary to remove the front Q-mod(ΔT′ _n , Q)-l1=3 chips of the channel estimation results of each user in the neighboring cell, and then expand the result (Q-mod(ΔT′ _n , Q ))-(W2-(W1+12))=1 chip set to 0. Wherein, S91 is the user channel estimation result of the adjacent cell before adjustment; S91' is the user channel estimation result of the adjacent cell after adjustment.

When ΔT′ _n =5 chips, it is necessary to remove the previous Q-mod(ΔT′ _n , Q)-l1=1 chip of the channel estimation result of each user in the neighboring cell, after removing the result (W2-(W1+l2))- (Q-mod(ΔT' _n , Q))=1 chip removed. Wherein, S92 is the user channel estimation result of the adjacent cell before adjustment; S92' is the user channel estimation result of the adjacent cell after adjustment.

It is assumed that W1=2chip, W2=4chip, l1=1chip, l2=1chip, Q=8chip, ΔT′ _n =2chip and the signal of the adjacent cell is behind the current cell. Wherein, S099 is the adjusted channel estimation result of the user in the cell.

At this point, because Q-mod(ΔT′ _n , Q)>l1+W2, the user channel estimation result will consist of a chip with a length of W1+l1+l2=4 and all 0s. Wherein, S99 is the channel estimation result of the adjacent cell users before adjustment, and S99' is the adjusted channel estimation result of the adjacent cell users.

Referring to Fig. 4j, suppose W1=12chip, W2=16chip, l1=6chip, l2=2chip, Q=8chip, and the signal of the neighboring cell is ahead of the own cell. S010 is the adjusted channel estimation result of the user in the cell.

When ΔT′ _n =5chip, it is necessary to extend l1-mod(ΔT′ _n , Q)=1 chip set to 0 before the channel estimation result of each user in the neighboring cell, and to extend mod(ΔT′ _n , Q )-(W2-(W1+12))=3 0-set chips. Wherein, S101 is the user channel estimation result of the adjacent cell before adjustment; S101' is the user channel estimation result of the adjacent cell after adjustment.

When ΔT′ _n =1chip, it is necessary to extend l1-mod(ΔT′ _n , Q)=5 chips set to 0 before the channel estimation results of each user in the neighboring cell, and after removing the result (W2-(W1+l2) )-mod(ΔT′ _n , Q)=1 chip is removed. Wherein, S102 is the user channel estimation result of the adjacent cell before adjustment; S102' is the user channel estimation result of the adjacent cell after adjustment.

Referring to Fig. 4k, it is assumed that W1=4chip, W2=10chip, l1=2chip, l2=2chip, Q=8chip, and the signal of the adjacent cell is ahead of the current cell. S011 is the adjusted channel estimation result of the user in the cell.

When ΔT′ _n =5 chips, it is necessary to remove the front mod(ΔT′ _n , Q)-l1=3 chips of the channel estimation results of each user in the neighboring cell, and extend mod(ΔT′ _n , Q)-( W2-(W1+l2))=1 chip with 0 set. Wherein, S111 is the user channel estimation result of the adjacent cell before adjustment; S111' is the user channel estimation result of the adjacent cell after adjustment.

When ΔT′ _n =3chip, it is necessary to remove the former mod(ΔT′ _n , Q)-l1=1 chip of the channel estimation results of the adjacent cells, and after removing the result (W2-(W1+l2))-mod (ΔT' _n , Q) = 1 chip. Wherein, S112 is the user channel estimation result of the adjacent cell before adjustment; S112' is the user channel estimation result of the adjacent cell after adjustment.

Suppose W1=2chip, W2=4chip, l1=1chip, l2=1chip, Q=8chip, when ΔT′ _n =6chip and the signal of the adjacent cell is ahead of the current cell. S055 is the adjusted channel estimation result of the user in the cell.

Since mod(ΔT′ _n , Q)>l1+W2, the user channel estimation result consists of a chip of all 0s with a length of W1+l1+l2=4. Wherein, S55 is the user channel estimation result of the adjacent cell before adjustment, and S55' is the user channel estimation result of the adjacent cell after adjustment.

Referring to Fig. 41, suppose W1=4chip, W2=10chip, l1=2chip, l2=2chip, Q=8chip, and the signal of the neighboring cell is ahead of the own cell. S012 is the adjusted channel estimation result of the user in the cell.

When ΔT′ _n =5chip, it is necessary to extend l1+Q-mod(ΔT′ _n , Q)=5 chips with 0 before the channel estimation results of each user in the neighboring cell, and after removing the result, Q-mod(ΔT′ _n , Q)+(W2-(W1+l2))=7 chips. Wherein, S121 is the user channel estimation result of the adjacent cell before adjustment; S121' is the user channel estimation result of the adjacent cell after adjustment.

When ΔT′ _n =2chip, the user channel estimation result will consist of a chip with a length of W1+l1+l2=6 and all 0s. Wherein, S122 is the user channel estimation result of the adjacent cell before adjustment; S122' is the user channel estimation result of the adjacent cell after adjustment, that is, all 0 chips with a length of 6 chips.

The adjustment of the estimated result of the combined channel response of each user in the current cell and each adjacent cell is similar to the above adjustment process, and will not be repeated here.

The present invention aims at the asynchronous mutual interference between the signals of adjacent cells of the same frequency in the time-slot CDMA system, and uses the relative delay difference between user signals in different cells to adjust the channel estimation results or combinations of the cell and/or each adjacent cell The estimated result of the channel response can effectively suppress the asynchronous and same-frequency interference of adjacent cells.

The following specifically takes three co-frequency adjacent cells as an example to illustrate the multi-cell joint detection process of the present invention.

The data part of the multi-user signal received by this cell plus two co-frequency cells with a closer distance or stronger interference can be expressed as the data blocks on both sides in Figure 1:

$\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Among them, _{A 0} and d ₀ are the transmission matrix and data of this cell; A _i and d _i are the transmission matrix and data of the i (i=1, 2) neighbor cell; Disturbance and noise power after disturbance.

The first step, multi-cell channel estimation:

The channel estimation codes of the three co-frequency cells correspond to the channel estimation code signals of the three code sets, and the channel estimation results of the three co-frequency adjacent cells can be obtained by using the multi-code set channel estimation method.

Assume that the channel estimation results of the three cells are h0', h1' and h2' respectively, where h0' is the channel estimation result of the local cell, h1' is the channel estimation result of the interfering cell 1, and h2' is the channel estimation result of the interfering cell 2 result.

As shown in Figure 5, assume that the total length of channel estimation in the cell is 24 chips (chips); this cell can perform channel estimation on up to 4 users, that is, the length of the channel estimation result (before adjustment) for each user in this cell is 6 chips; 1 Channel estimation can be performed on up to 6 users, that is, the channel estimation result length (before adjustment) of each user in adjacent cell 1 is 4 chips; adjacent cell 2 can perform channel estimation on up to 3 users, that is, the channel estimation result of each user in adjacent cell 2 The length of the estimated result (before adjustment) is 8chips; the adjacent cell 1 is 5 chips ahead of the current cell, and the adjacent cell 2 is 7 chips behind the current cell; the spreading code length Q=4.

Use a, b, c, d to denote the channel estimation results of 4 users in this cell, respectively, use e, f, g, h, i, j to denote the channel estimation results of 6 users in adjacent cell 1, and use k, l , m represent the channel estimation results of 3 users of adjacent cell 2, wherein a=(a1, a2, ..., a6), and other representations are similar to a, then the channel estimation results of each cell can be specifically expressed as follows:

h0'=(a1, a2, a3, a4, a5, a6, b1, b2, b3, b4, b5, b6, c1, c2, c3, c4, c5, c6, d1, d2, d3, d4, d5, d6);

h1'=(f2, f3, f4, g1, g2, g3, g4, h1, h2, h3, h4, i1, i2, i3, i4, j1, j2, j3, j4, e1, e2, e3, e4, f1);

h2'=(m2, m3, m4, m5, m6, m7, m8, k1, k2, k3, k4, k5, k6, k7, k8, l1, l2, l3, l4, l5, l6, l7, l8, m1);

Because the channel estimation code assigned to each user (such as the midamble code in Figure 1) is cyclically shifted, this also ensures that the channel estimation result is cyclic in the case of relative time delay, and the relative time delay of neighboring cell 1 is 5 chips ahead, so e1, e2, e3, e4, and f1 in h1' cycle to the end of the channel estimation result of the cell; the relative delay of adjacent cell 2 is 7 chips behind, so m2, m3, m4, m5 in h1' , m6, m7, m8 cycle to the front of the cell channel estimation results.

In the second step, there are two processing methods, one is to adjust the channel estimation results of each user in different cells according to the relative time delay and then calculate the estimated result of the combined channel response, and the other is to not calculate the channel estimation results of each user in different cells Adjusting, calculating the estimated result of the combined channel response and adjusting the estimated result of the combined channel response according to the relative time delay.

The first method: first adjust the channel estimation results of each user in different cells:

This cell: from the first chip, 6 chips are sequentially intercepted from the total channel estimation result h0′ of this cell, and the channel estimation results of users a, b, c, and d are sequentially obtained, and 0 is added before and after this cell The lengths are equal, that is, L1=L2=L=2chip. Then the adjusted channel estimation result is as follows:

a=(0,0,a1,a2,...,a6,0,0);

b=(0,0,b1,b2,...,b6,0,0);

c=(0,0,c1,c2,...,c6,0,0);

d=(0, 0, d1, d2, . . . , c6, 0, 0).

Neighboring cell 1: Since neighboring cell 1 is ahead of the own cell by 5 chips, starting from the 24th-5+1=20th chip, 4 chips are cyclically intercepted in h1′, and users e, f, g, h, The channel estimation results of i and j are then expanded: because W1+L2=6+2>4=W2, mod(ΔT′ _n , Q)=mod(5,4)=1<2=L1, add L1- mod(ΔT′ _n , Q)=2-mod(5,4)=1 chip set to 0, followed by L2+(W1-W2)+mod(ΔT′ _n , Q)=5 codes set to 0 piece.

The adjusted channel estimation results are as follows:

e=(0, e1, e2, e3, e4, 0, 0, 0, 0, 0);

f = (0, f1, f2, f3, f4, 0, 0, 0, 0, 0);

g=(0, g1, g2, g3, g4, 0, 0, 0, 0, 0);

h=(0, h1, h2, h3, h4, 0, 0, 0, 0, 0);

i=(0, i1, i2, i3, i4, 0, 0, 0, 0, 0);

j=(0, j1, j2, j3, j4, 0, 0, 0, 0, 0).

Neighboring cell 2: Because the neighboring cell 2 lags behind the own cell by 7 chips, the first 8 chips are cyclically intercepted in h2' from the 7th + 1 = 8 chips, and the channel estimation results of users k, l, and m are sequentially obtained , and then expand. Because W1+L2=8=W2, mod(ΔT′ _n , Q)=mod(7,4)=3>2+(6-8)=L2+(W1-W2), but Q-mod(ΔT′ _n , Q)=4-mod(7,4)=1<2=L1, so add L1-(Q-mod(ΔT′ _n ,Q))=2-(4-mod(7,4 ))=1 chip set to 0, add L2+(W1-W2)+(Q-mod(ΔT′ _n , Q))=2+(6-8)+(4-mod(5 , 4))=1 chip set to 0.

The adjusted channel estimation results are as follows:

k=(0, k1, k2, k3, k4, k5, k6, k7, k8, 0);

l=(0, l1, l2, l3, l4, l5, l6, l7, l8, 0);

m=(0, m1, m2, m3, m4, m5, m6, m7, m8, 0).

Thus, the channel estimation results of users in different cells are adjusted to equal lengths of 10 chips according to their relative time delays.

Then calculate the estimated result of the combined channel response:

The user's combined channel response is obtained by performing convolution operations on the user's spreading code and the channel estimation result, that is, b=Ch, and the length of b is Q+W-1=4+10-1=13chip. Then the estimation result of the combined channel response of each cell can be expressed as:

This district:

a'=(0,0,a'1,a'2,...,a'9,0,0);

b'=(0,0,b'1,b'2,...,b'9,0,0);

c'=(0,0,c'1,c'2,...,c'9,0,0);

d'=(0,0,d'1,d'2,...,c'9,0,0);

Neighboring cell 1:

e'=(0,e'1,e'2,...,e'7,0,0,0,0,0);

f'=(0, f'1, f'2, ..., f'7, 0, 0, 0, 0, 0);

g'=(0,g'1,g'2,...,g'7,0,0,0,0,0);

h'=(0,h'1,h'2,...,h'7,0,0,0,0,0);

i'=(0,i'1,i'2,...,i'7,0,0,0,0,0);

j'=(0,j'1,j'2,...,j'7,0,0,0,0,0);

Neighboring cell 2:

k'=(0,k'1,k'2,...,k'11,0);

l'=(0,l'1,l'2,...,l'11,0);

m'=(0, m'1, m'2,..., m'11, 0).

The second method: do not adjust the channel estimation results of each user in different cells:

This cell: from the first chip, 6 chips are sequentially intercepted from the total channel estimation result h0′ of this cell, and the channel estimation results of users a, b, c, and d are obtained in sequence:

a=(a1, a2, ..., a6);

b = (b1, b2, ..., b6);

c = (c1, c2, ..., c6);

d=(d1,d2,...,c6);

Neighboring cell 1: Since neighboring cell 1 is ahead of the own cell by 5 chips, starting from the 24th-5+1=20th chip, 4 chips are cyclically intercepted in h1′, and users e, f, g, h, Channel estimation results of i and j:

e=(e1, e2, e3, e4);

f=(f1, f2, f3, f4);

g=(g1, g2, g3, g4);

h=(h1, h2, h3, h4);

i=(i1, i2, i3, i4);

j=(j1, j2, j3, j4);

Neighboring cell 2: Because the neighboring cell 2 lags behind the own cell by 7 chips, the first 8 chips are cyclically intercepted in h2' from the 7th + 1 = 8 chips, and the channel estimation results of users k, l, and m are sequentially obtained :

k=(k1, k2, k3, k4, k5, k6, k7, k8);

l=(l1,l2,l3,l4,l5,l6,l7,l8);

m=(m1, m2, m3, m4, m5, m6, m7, m8).

An estimate of the combined channel response is then computed:

The user's combined channel response is obtained by performing convolution operations on the user's spreading code and channel estimation results, that is, b=Ch, and the length of b is Q+W-1, which varies according to the W of each cell. Then the estimation result of the combined channel response of each cell can be expressed as:

This cell: W=6chip, so the length of combined channel response is 4+6-1=9chip

a'=(a'1,a'2,...,a'9);

b'=(b'1,b'2,...,b'9);

c'=(c'1,c'2,...,c'9);

d'=(d'1,d'2,...,c'9);

Neighboring cell 1: W=4chip, so the length of combined channel response is 4+4-1=7chip

e'=(e'1, e'2, ..., e'7);

f'=(f'1, f'2,..., f'7);

g'=(g'1,g'2,...,g'7);

h'=(h'1, h'2, ..., h'7);

i'=(i'1, i'2,..., i'7);

j'=(j'1, j'2,..., j'7);

Neighboring cell 2: W=8chip, so the length of combined channel response is 4+8-1=11chip

k'=(k'1,k'2,...,k'11);

l'=(l'1,l'2,...,l'11);

m'=(m'1, m'2, ..., m'11).

Then adjust the estimated result of the combined channel response according to the relative time delay:

This cell: assume that the lengths of zeros at the front and rear of this cell are equal, that is, L3=L4=L=2chip. Then the estimated result of the adjusted combined channel response is as follows:

a'=(0,0,a'1,a'2,...,a'9,0,0);

b'=(0,0,b'1,b'2,...,b'9,0,0);

c'=(0,0,c'1,c'2,...,c'9,0,0);

d'=(0,0,d'1,d'2,...,c'9,0,0);

Neighboring cell 1: because W3+L4=9+2>7=W4, mod(ΔT′ _n , Q)=mod(5,4)=1<2=L3, so add L3-mod(ΔT ' _n , Q)=2-mod(5,4)=1 chip set to 0, and the result is supplemented with L4+(W3-W4)+mod(ΔT' _n , Q)=2+(9-7) +mod(5,4)=5 chips set to 0. The adjusted channel estimation results are as follows:

e'=(0,e'1,e'2,...,e'7,0,0,0,0,0);

f'=(0, f'1, f'2, ..., f'7, 0, 0, 0, 0, 0);

g'=(0,g'1,g'2,...,g'7,0,0,0,0,0);

h'=(0,h'1,h'2,...,h'7,0,0,0,0,0);

i'=(0,i'1,i'2,...,i'7,0,0,0,0,0);

j'=(0,j'1,j'2,...,j'7,0,0,0,0,0);

Neighboring cell 2: because

W3+L4=9+2=11=W4, mod(ΔT′ _n , Q)=mod(7,4)=3>2+(9-11)=L4+(W3-W4), but Q-mod( ΔT' _n , Q)=4-mod(7,4)=1<2=L3, so add L3-(Q-mod(ΔT' _n , Q))=2-(4-mod( 7, 4))=1 code chip set to 0, supplement L4+(W3-W4)+(Q-mod(ΔT′ _n , Q))=2+(9-11)+(4-mod( 5, 4)) = 1 chip set to 0.

The adjusted channel estimation results are as follows:

k'=(0,k'1,k'2,...,k'11,0);

l'=(0,l'1,l'2,...,l'11,0);

m'=(0, m'1, m'2,..., m'11, 0).

Thus, the estimated results of combined channel responses of users in different cells are adjusted to have an equal length of 13 chips according to their relative time delays.

The third step is to use the estimated results of combined channel responses of different users in each cell to perform multi-cell joint detection to obtain detection data.

First, group the code channels of the three cells:

According to the first grouping method based on the cell to which the code channel belongs, the code channel can be divided into three groups according to the number of cells. The grouped signals can be expressed as:

e＝A ₀ d ₀ +A ₁ d ₁ +A ₂ d ₂ +n ₀ (2)

Wherein, the transmission matrix A _i , i=0, 1, 2 is formed by the estimated result vector of the combined channel response of each user code channel of the cell given in the second step.

According to the second grouping method based on code channel power or amplitude, the channel response or combined channel response obtained by the multi-cell channel estimation result, or the output result of each code channel matched filter, can estimate the power of each code channel signal; then , divide all the code channels into two groups according to the strength of the power, the code channel of the user to be detected and the interference code channel with strong power are divided into the code channel group participating in the joint detection, and the code channel with weak power is divided into the interference code channel in the channel group. The grouped signals can be expressed as:

e＝A _S d _S +(A _I d _I +n ₀ ) (3)

Among them, A _S and d _S are the transmission matrix and data of participating in the joint detection code channel grouping; A _I and d _I are the transmission matrix and data of the interference code channel grouping; the construction method of A _S and A _I is the same as the first grouping method .

According to the third grouping method based on code channel correlation, first estimate the mean value of the correlation between all code channels of non-to-be-detected users and all code channels of users to be detected (the code channel here refers to the composite code of spreading code and scrambling code , or the estimated value of the combined channel response), all the code channels are divided into two groups according to the strength of the average correlation value, and the code channels of the user to be detected and all code channels with strong correlation with their code channels are assigned to participate in the joint detection In the code channel grouping, the remaining code channels are divided into interference code channel groups. The grouped signals can be expressed as:

e＝A _S d _S +(A _I d _I +n ₀ ) (4)

Among them, A _S and d _S are the transmission matrix and data of participating in the joint detection code channel grouping; A _I and d _I are the transmission matrix and data of the interference code channel grouping; the construction method of A _S and A _I is the same as the first grouping method . Use the same expression as the second grouping method.

Then, perform joint detection:

For the first code channel grouping method, the joint detection can adopt the method of linear block equalization + interference cancellation:

1) A joint detection method in which each group performs its own linear block equalization on the total received signal, that is, a single cell joint detection algorithm;

2) Perform interference recovery based on the detected results of each group;

3) Offset the non-group interference from the total received signal to obtain a net signal;

4) A joint detection method of performing linear block equalization on the net signal of the group in which the user to be detected is located, to obtain the result of the user to be detected.

The above process only uses interference cancellation once. In a real system, multiple offsets can be used as needed to achieve the desired performance.

For the second and third code channel grouping methods, the code channel grouping participating in the joint detection is detected by a joint detection method of linear block equalization.

Thus, the estimated soft output value of the transmitted data d _S is:

${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}}_{\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}^{<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

where the matrix T is given by:

${\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}\mathrm{<span\; class="notranslate">\; I</span>}& \mathrm{<span\; class="notranslate">\; MF</span>}\\ {\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}^{<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}& \mathrm{<span\; class="notranslate">\; ZF</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; BLE</span>}\\ {\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}^{<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}& \mathrm{<span\; class="notranslate">\; MMSE</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; BLE</span>}\end{array}\right.<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

in,

${\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; \{</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; no</span>}}^{<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; \}</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; \{</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&Center\; Dot;</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; \}</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; I</span>}}^{<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

During implementation, the interference can be treated as white noise, or the whitening process can be performed first for the colored noise interference. Wherein, the characteristics of the interference can be calculated from the interference code channel grouping and the measured background noise.

It can be seen that the present invention adjusts the channel estimation results of each user in different cells or the estimation result of their combined channel response based on the relative delay difference between the user signals of the same-frequency adjacent cells in the time-slotted CDMA system, and then uses the combined channel response Multi-cell joint detection is carried out based on the estimated result of the multi-cell, and the detection data is obtained, which effectively suppresses the interference between adjacent cells of the same frequency.

The method of the invention can be used in a time slot CDMA system or a wireless communication system using a similar signal structure.

While the invention has been described by way of example, those skilled in the art will appreciate that there are many variations and changes to the invention without departing from the spirit of the invention, and it is intended that the appended claims cover such variations and changes without departing from the spirit of the invention.

Claims (10)

1, a kind of time-slot code division multiple access system multi-cell joint detection method, it is characterized in that, described method comprises the steps: A. Carry out multi-code set channel estimation on the received signal data, and obtain the channel estimation results of this cell and each adjacent cell; B, sequentially intercepting the channel estimation results corresponding to each user in the cell from the channel estimation results of the local cell and the channel estimation results of the adjacent cells; C. Adjusting the channel estimation results of each user in the current cell and/or each adjacent cell according to the relative time delay difference between user signals in different cells; D. Calculate the estimated result of the combined channel response of this cell and the adjacent cell according to the spreading code of each user and the corresponding adjusted channel estimation result; E. Perform joint detection on the received data by using the estimation results of the combined channel response of each cell to obtain detection data. 2, a kind of time-slot code division multiple access system multi-cell joint detection method, it is characterized in that, described method comprises the steps: A', performing multi-code set channel estimation on the received signal data, and obtaining the channel estimation results of this cell and each adjacent cell; B', sequentially intercepting channel estimation results corresponding to each user in the cell from the channel estimation results of this cell and the channel estimation results of adjacent cells; C', according to each user's spreading code and the corresponding channel estimation result, calculate the estimated result of the combined channel response of this cell and the adjacent cell; D', adjusting the estimated result of the combined channel response of each user in the current cell and the adjacent cell according to the relative time delay difference between user signals in different cells; E′. Perform joint detection on the received data by using the adjusted estimation result of the combined channel response to obtain detection data. 3, according to claim 1 and 2 described time slot code division multiple access system multi-cell joint detection method, 11+mod (ΔT _n ', Q) chip that puts 0, after the result expands 12+(W1-W2 )-mod(ΔT _n ', Q) chips set to 0; If mod(ΔT _n ′, Q)>12+(W1-W2) and Q-mod(ΔT _n ′, Q)≤11, then extend 11-(Q-mod(ΔT _n ′, Q)) chips set to 0, and after the result, 12+(W1-W2)+(Q-mod(ΔT _n ′, Q)) chips set to 0 are extended; If mod(ΔT _n ′, Q)>12+(W1-W2) and Q-mod(ΔT _n ′, Q)>11, then when mod(ΔT _n ′, Q)≤12+W1, in the adjacent cell Each user channel estimation result is extended with 11+mod(ΔT _n ′, Q) code chips set to 0, and after the result is removed, mod(ΔT _n ′, Q)-(12+(W1-W2)) chips; when When Q-mod(ΔT _n ′, Q)≤11+W2, remove the first (Q-mod(ΔT _n ′, Q))-11 chips of the channel estimation results of each user in the neighboring cell, and then extend the result by 12+( W1-W2)+(Q-mod(ΔT _n ′, Q)) chips set to 0; when mod(ΔT _n ′, Q)>12+W1 and Q-mod(ΔT _n ′, Q)>11 When +W2, the user channel estimation result consists of a chip with a length of W1+11+12 and all 0s; (2) When the adjacent cell signal is ahead of the own cell, If mod(ΔT _n ′, Q)≤11, then extend 11-mod(ΔT _n ′, Q) code chips set to 0 before the channel estimation results of each user in the neighboring cell, and then extend 12+(W1-W2) after the result +mod(ΔT _n ', Q) chips set to 0; If mod(ΔT _n ′, Q)>11 and Q-mod(ΔT _n ′, Q)≤12+(W1-W2), then extend 11+(Q-mod(ΔT _n ′, Q)) chips set to 0, and after the result, 12+(W1-W2)-(Q-mod(ΔT _n ′, Q)) chips set to 0 are extended; If mod(ΔT _n ′, Q)>11 and Q-mod(ΔT _n ′, Q)>12+(W1-W2), then when mod(ΔT _n ′, Q)≤11+W2, remove the neighboring cell The first mod(ΔT _n ′, Q)-11 chips of each user’s channel estimation result, after which the result is extended with 12+(W1-W2)+mod(ΔT _n ′, Q) chips set to 0; when Q- When mod(ΔT _n ', Q)≤12+W1, it is characterized in that, in the step B and step B', the channel estimation results of each user are intercepted according to the following steps: b1. Setting the total length Ln of the channel estimation results of each cell; b2. Obtain the relative time delay difference ΔT _n between each adjacent cell and the user signal of this cell, and round the relative time delay difference ΔT _n to obtain the standard time delay difference ΔT _n ′; b3. Intercepting the channel estimation results of each user in the cell sequentially from the first chip of the total channel estimation result in the cell; b4. If the adjacent cell signal lags behind the own cell, cyclically intercept the channel estimation results of each user in the adjacent cell from the ΔT _n '+1 chip of the total channel estimation result of the adjacent cell; b5. If the signal of the adjacent cell is ahead of the current cell, the channel estimation result of each user in the adjacent cell is cyclically intercepted from the Ln-ΔT _n '+1 chip of the total channel estimation result of the adjacent cell . 4. The multi-cell joint detection method of a time-slotted code division multiple access system according to claim 3, wherein the operation of rounding the relative time delay difference ΔT _n is specifically: The relative delay difference ΔT _n is rounded down, or up, or customized. 5. The multi-cell joint detection method of a time-slotted code division multiple access system according to claim 3, wherein said step C specifically comprises: C1, setting the length of the channel estimation result of the user in this cell is W1, the length of the channel estimation result of the adjacent cell user is W2; the length of the spreading code is Q; C2. Extend the channel estimation results of each user in the cell in the following manner: Before the channel estimation results of each user in this cell, extend 11 code chips with a predetermined length of 0, if no adjacent cell signal is ahead of the signal of this cell, then do not extend that is 11=0; afterward extend 12 code chips with a predetermined length of 0 slice, if there is no adjacent cell signal lagging behind the local cell signal, then no extension, that is, 12=0; C3. When W1+12≥W2, expand the channel estimation results of each user in each adjacent cell in the following manner: (1) When the adjacent cell signal lags behind this cell, If mod(ΔT _n ′, Q)≤12+(W1-W2), then extend 11+(Q-mod(ΔT _n ′, Q)) chips set to 0, after removing the result (Q-mod(ΔT _n ′, Q))-(12+(W1-W2)) chips; when mod(ΔT _n ′, Q)>11 When +W2 and Q-mod(ΔT _n ′, Q)>12+W1, the user channel estimation result consists of a chip with a length of W1+11+12 and all 0s; C4. When W1+12<W2, expand the channel estimation results of each user in each adjacent cell in the following manner: (1) When the adjacent cell signal lags behind this cell, If Q-mod(ΔT _n ′, Q)≤11, then extend 11-(Q-mod(ΔT _n ′, Q)) chips set to 0 before the channel estimation results of each user in the neighboring cell; if Q-mod (ΔT _n ′, Q)≥(W2-(W1+12)), then extend (Q-mod(ΔT _n ′, Q))-(W2-(W1+12)) zero-set codes after the result slice, if Q-mod(ΔT _n ′, Q)<(W2-(W1+12)), then after removing the result (W2-(W1+12))-(Q-mod(ΔT _n ′, Q)) chips; If Q-mod(ΔT _n ′, Q)>11, then extend 11+mod(ΔT _n ′, Q) chips set to 0 before the channel estimation results of each user in the neighboring cell; if mod(ΔT _n ′, Q )≤W1+12, then remove mod(ΔT _n ′, Q)+(W2-(W1+12)) chips, if mod(ΔT _n ′, Q)>W1+12, then the user channel estimation The result will consist of a chip of all 0s with a length of W1+11+12, regardless of the previous extension; Or, if Q-mod(ΔT _n ′, Q)>11 and Q-mod(ΔT _n ′, Q)≤11+W2, remove the previous Q-mod(ΔT _n ′, Q)-11 chips; if Q-mod(ΔT _n ′, Q)≥(W2-(W1+12)), the result is post-extended (Q-mod(ΔT _n ′, Q))-(W2- (W1+12)) chips set to 0; if Q-mod(ΔT _n ′, Q)<(W2-(W1+12)), then after removing the result (W2-(W1+12))-( Q-mod(ΔT _n ′, Q)) chips; if Q-mod(ΔT _n ′, Q)>11+W2, then the user channel estimation result consists of a length of W1+11+12 all 0 Chip composition; (2) When the adjacent cell signal is ahead of the own cell, If mod(ΔT _n ′, Q)≤11, then extend 11-mod(ΔT _n ′, Q) chips set to 0 before the channel estimation results of each user in the neighboring cell; if mod(ΔT _n ′, Q)≥ (W2-(W1+12)), then extend mod(ΔT _n ′, Q)-(W2-(W1+12)) chips set to 0 after the result, if mod(ΔT _n ′, Q)< (W2-(W1+12)), after removing the result (W2-(W1+12))-mod(ΔT _n ', Q) chips; If mod(ΔT _n ′, Q)>11 and mod(ΔT _n ′, Q)≤11+W2, remove the previous mod(ΔT _n ′, Q)-11 chips of the channel estimation results of each user in the neighboring cell; If mod(ΔT _n ′, Q)≥(W2-(W1+12)), the result will be extended mod(ΔT _n ′, Q)-(W2-(W1+12)) chips set to 0; if mod(ΔT _n ′, Q)<(W2-(W1+12)), then remove the result (W2-(W1+12))-mod(ΔT _n ′, Q) chips; if mod(ΔT _n ', Q)>11+W2, then the user channel estimation result consists of a chip with a length of W1+11+12 and all 0s; Or, if mod(ΔT _n ′, Q)>11, then extend 11+Q-mod(ΔT _n ′, Q) chips set to 0 before the channel estimation results of each user in the neighboring cell; if Q-mod(ΔT _n ′, Q)≤W1+12, Q-mod(ΔT _n ′, Q)+(W2-(W1+12)) chips after removal; if Q-mod(ΔT _n ′, Q)>W1+ 12, the user channel estimation result will consist of a chip with length W1+11+12 all 0s, regardless of the previous extension. 6. The multi-cell joint detection method of a time-slotted code division multiple access system according to claim 3, wherein said step D' specifically comprises: D1', setting the length of the estimated result of the combined channel response of the user in this cell is W3, the length of the estimated result of the combined channel response of the adjacent cell user is W4; the length of the spreading code is Q; D2', expand the estimated result of the combined channel response of each user in the cell in the following manner: Before the estimated result of combined channel response of each user in this cell, extend a predetermined length of 13 code chips set to 0. If no adjacent cell signal is ahead of the signal of this cell, then no extension, that is, 13=0; after that, extend a predetermined length of 14 chips For the chips set to 0, if there is no adjacent cell signal lagging behind the local cell signal, it will not be extended, that is, 14=0; D3', when W3+14≥W4, expand the estimated result of the combined channel response of each user in each adjacent cell in the following manner: (1) When the adjacent cell signal lags behind this cell, If mod(ΔT _n ′, Q)≤14+(W3-W4), then extend 13+mod(ΔT _n ′, Q) chips set to 0 before the estimated result of combined channel response of each user in the adjacent cell, and the result Post-expand 14+(W3-W4)-mod(ΔT _n ', Q) chips set to 0; If mod(ΔT _n ′, Q)>14+(W3-W4) and Q-mod(ΔT _n ′, Q)≤13, then extend 13-(Q- mod(ΔT _n ′, Q)) 0-set chips, after the result, 14+(W3-W4)+(Q-mod(ΔT _n ′, Q)) 0-set chips are extended; If mod(ΔT _n ′, Q)>14+(W3-W4) and Q-mod(ΔT _n ′, Q)>13, then extend 13+mod(ΔT _n ′, Q) chips set to 0, after removing the result mod(ΔT _n ′, Q)-(14+(W3-W4)) chips; or remove the estimated result of the combined channel response of each user in the adjacent cell Before (Q-mod(ΔT _n ′, Q))-13 chips, after the result, 14+(W3-W4)+(Q-mod(ΔT _n ′, Q)) chips set to 0 are extended; (2) When the adjacent cell signal is ahead of the own cell, If mod(ΔT _n ′, Q)≤13, then extend 13-mod(ΔT _n ′, Q) chips set to 0 before the estimated result of the combined channel response of each user in the adjacent cell, and then extend the result by 14+(W3 -W4)+mod(ΔT _n ', Q) chips set to 0; If mod(ΔT _n ′, Q)>13 and Q-mod(ΔT _n ′, Q)≤14+(W3-W4), then extend 13+(Q- mod(ΔT _n ′, Q)) 0-set chips, and after the result, 14+(W3-W4)-(Q-mod(ΔT _n ′, Q)) 0-set chips are extended; If mod(ΔT _n ′, Q)>13 and Q-mod(ΔT _n ′, Q)>14+(W3-W4), remove the former mod(ΔT _n ′ , Q)-13 chips, after the result, extend 14+(W3-W4)+mod(ΔT _n ′, Q) chips set to 0; or extend 13 before the estimated result of the combined channel response of each user in the adjacent cell +(Q-mod(ΔT _n ′, Q)) chips set to 0, after removing the result (Q-mod(ΔT _n ′, Q))-(14+(W3-W4)) chips; D4' When W3+14<W4, expand the estimated results of the combined channel response of each user in each adjacent cell in the following manner: (1) When the adjacent cell signal lags behind this cell, If Q-mod(ΔT _n ′, Q)≤13, then extend 13-(Q-mod(ΔT _n ′, Q)) chips set to 0 before the estimated result of combined channel response of each user in the adjacent cell; if Q-mod(ΔT _n ′, Q)≥(W4-(W3+14)), after the result, expand (Q-mod(ΔT _n ′, Q))-(W4-(W3+14)) and set to 0 chip, if Q-mod(ΔT _n ′, Q)<(W4-(W3+14)), after removing the result (W4-(W3+14))-(Q-mod(ΔT _n ′, Q) ) chips; If Q-mod(ΔT _n ′, Q)>13, then extend 13+mod(ΔT _n ′, Q) chips set to 0 before the estimated result of combined channel response of each user in the adjacent cell, and after removing the result mod( ΔT _n ', Q)+(W4-(W3+14)) chips; Or, if Q-mod (ΔT _n ′, Q)>13, remove the first Q-mod (ΔT _n ′, Q)-13 chips of the estimated result of the combined channel response of each user in the adjacent cell; if Q-mod ( _{If _} Q-mod(ΔT _n ′, Q)<(W4-(W3+14)), after removing the result (W4-(W3+14))-(Q-mod(ΔT _n ′, Q)) chips; (2) When the adjacent cell signal is ahead of the own cell, If mod(ΔT _n ′, Q)≤13, extend 13-mod(ΔT _n ′, Q) chips set to 0 before the estimated result of combined channel response of each user in the adjacent cell; if mod(ΔT _n ′, Q )≥(W4-(W3+14)), the result is extended mod(ΔT _n ′, Q)-(W4-(W3+14)) chips set to 0, if mod(ΔT _n ′, Q)< (W4-(W3+14)), after removing the result (W4-(W3+14))-mod(ΔT _n ', Q) chips; If mod(ΔT _n ′, Q)>13, remove the first mod(ΔT _n ′, Q)-13 chips of the estimated result of the combined channel response of each user in the adjacent cell; if mod(ΔT _n ′, Q)≥( W4-(W3+14)), extend mod(ΔT _n ′, Q)-(W4-(W3+14)) chips set to 0 after the result, if mod(ΔT _n ′, Q)<(W4 -(W3+14)), after removing the result (W4-(W3+14))-mod(ΔT _n ', Q) chips; Or, if mod(ΔT _n ′, Q)>13, extend 13+Q-mod(ΔT _n ′, Q) chips set to 0 before the estimated result of combined channel response of each user in the adjacent cell; after removing the result, Q - mod (ΔT _n ', Q)+(W4-(W3+14)) chips. 7. The multi-cell joint detection method of the time-slotted code division multiple access system according to claim 1 or 2, characterized in that, the estimated result of the combined channel response of each user in the local cell and the adjacent cell is b=Ch, where , C is the spreading code corresponding to a code channel of a user in the local or adjacent cell,  is the convolution operator, and h is the channel estimation result of the user. 8. The multi-cell joint detection method of a time-slotted code division multiple access system according to claim 1, characterized in that, between step B and step D, the step further comprises: The code channels of each adjacent cell are grouped. 9. The multi-cell joint detection method of a time-slotted code division multiple access system according to claim 2, characterized in that, between step B' and step D', the step further includes: The code channels of each adjacent cell are grouped. 10, according to claim 8 or 9 described time-slot code division multiple access system multi-cell joint detection method, it is characterized in that, the code channel of each adjacent cell is grouped in the following manner: grouping the code channels of each adjacent cell based on the cell to which the code channel belongs; and/or grouping code channels of neighboring cells based on code channel power or amplitude; and/or The code channels of each neighboring cell are grouped based on the code channel correlation.

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