CN103795437B - The method and apparatus for selecting multidiameter - Google Patents

Abstract

The invention discloses a method and device for selecting multipath delay. The method includes performing multipath search on target users and interfering users respectively to obtain multipath related information; according to the energy path information containing target user signal energy obtained through searching And the energy path information of the signal energy of the interfering user is used to select the multipath delay of the target user. Using the method and device of the present invention, compared with the prior art, the selected multipath delay can better play the performance of advanced receivers, suppress interference better, improve the combined SINR, and reduce the bit error rate of the receiver .

Description

Method and device for selecting multipath delay

technical field

The present invention relates to the technical field of CDMA (Code Division Multiple Access, Code Division Multiple Access) baseband receiver, especially related to the multipath distribution in Rake receiver, more specifically, the present invention relates to a method of selecting multipath delay and Method and apparatus for dispensing.

Background technique

In code division multiple access CDMA system, Rake receiver is widely used. As shown in Figure 1, the Rake receiver first needs to search the energy path of the signal to find the multipath positions with signal energy, and then distribute the received signals at these multipath positions to the descrambling and despreading unit for descrambling and despreading, and finally Maximum ratio combining is performed on the descrambled and despread symbols, so as to obtain soft symbols that can be judged or decoded.

With the development of receiver technology, advanced receivers with superior performance have also begun to be applied to practical systems, such as MMSE (Minimum Mean Square Error, minimum mean square error), GRAKE (General Rake, general Rake) receivers, etc.

For Rake receivers, the assigned multipath positions usually contain signal energy, while for advanced receivers, multipath positions may not contain signal energy, but only interference energy. Usually, the multipath that contains signal energy is called energy path, and the multipath that contains only interference energy but does not contain signal energy is called noise path. Continuing to refer to Figure 1, the results of energy path search and noise path selection are distributed to the descrambling and despreading unit, and the advanced receiver obtains the maximum signal energy by combining the descrambling and despreading symbols of these energy paths and noise paths, while suppressing Interference, so that better performance can be obtained compared to the Rake receiver.

However, whether it is a Rake receiver or an advanced receiver, on the premise of the same receiver algorithm, multipath allocation, including energy paths and noise paths, will affect the final system performance and the bit error rate of received symbols. This is because, if the energy path is selected properly, the signal energy can be collected to the maximum; if the noise path is selected properly, the interference can be suppressed to the greatest extent, so the selection module of multipath delay is an important module related to system performance , therefore, how to provide a method for selecting the multipath delay to maximize the collection of signal energy and suppress interference has become a problem that needs to be solved urgently.

Contents of the invention

In order to overcome the inappropriate selection of multipath delays in the prior art, thus making it impossible to maximize the performance of advanced receivers and defects, the purpose of the present invention is to provide a method and device for selecting multipath delays, in order to obtain more Good system performance, and lower received symbol error rate.

In order to achieve the purpose of the present invention, the present invention adopts the following technical solutions to realize:

A method of selecting multipath delay comprising:

A. Perform multipath search on target users and interfering users respectively to obtain multipath related information;

B. The multipath delay selection of the target user is performed according to the energy path information containing the signal energy of the target user and the energy path information of the signal energy of the interference user obtained through searching.

Preferably, in the step A, the multipath search refers to the search for energy paths, and the multipath related information includes energy path delay and signal energy contained in each path.

Preferably, in the step B, the multipath delay selection of the target user includes selecting an energy path and selecting a noise path, which together constitute the finally selected multipath delay.

Preferably, when performing the step B, the energy path selection method includes:

C. Select the energy path of the target user. When the signal energy of the target user is less than a preset threshold, they may not be combined.

Preferably, when performing the step B, the noise path selection method includes:

D. Select the noise path of the target user according to the principle of suppressing inter-multipath interference.

Preferably, the step of selecting the noise path of the target user according to the principle of suppressing inter-multipath interference includes:

D1. Select an energy path of the target user as a potential merged multipath, and make its delay del_ef;

D2. Select one of the interference multipaths, and let its delay be del_int, wherein the interference multipath refers to the energy paths of other target users except the energy path of the selected target user and the energy paths of all interference users , all of which have inter-path interference to the selected multipath;

D3. Generate a noise path to suppress interference from interfering multipath;

D4. Select a part of noise paths to participate in the final combination based on at least one criterion.

Preferably, in the step D3, the step of generating a noise path for suppressing multipath interference includes:

D31. Select a multipath from the energy paths of the target user and the interference user as the reference multipath, and make its delay del_lp;

D32. Obtain the delay del_nf of the target noise path according to the following mathematical formula:

del_nf = del_ef+order*(del_lp-del_int);

Among them, order is an integer greater than 0, indicating the order of the noise path.

Preferably, in said step D3, it also includes:

D33. When order=1 and the reference multipath is the selected energy path, del_lp=del_ef at this time, then the delay del_nf of the target noise path is obtained according to the following mathematical formula:

del_nf = 2*del_lp-del_int;

That is, the noise path del_nf and the interference multipath del_int are symmetrical to the selected energy path del_ef.

Preferably, in the step D4, the criteria include:

1) The noise path generated by the energy path with high energy is given priority;

2) The noise path generated by the interference path with high energy is given priority;

3) The noise path generated by the reference path with high energy is given priority;

4) The noise path with small order is given priority;

5) Only one of the two paths whose multipath delay interval is smaller than a certain threshold is selected.

An apparatus for selecting multipath delay, comprising:

The target user multipath search module is used to perform multipath search on the target user to obtain multipath related information;

The interfering user multipath search module is used to perform multipath searching on the interfering user and obtain multipath related information;

The target user multipath delay selection module is configured to perform multipath delay selection of the target user according to the energy path information containing the energy of the target user signal and the energy path information of the interference user signal energy obtained through searching.

Preferably, the multipath search refers to the search for energy paths, and the multipath related information includes energy path delay and signal energy contained in each path.

Preferably, the target user multipath delay selection module selects the target user's multipath delay including selecting an energy path and selecting a noise path, which together constitute the finally selected multipath delay.

Preferably, the target user multipath delay selection module is also used to select the target user's energy path, and when the signal energy of the target user is less than a preset threshold, it may not be combined.

Preferably, the target user multipath delay selection module is also used to select the target user's noise path according to the principle of suppressing inter-multipath interference.

Preferably, the step of selecting the target user's noise path according to the principle of suppressing inter-multipath interference by the target user multipath delay selection module includes:

1) Select an energy path of the target user as a potential merged multipath, and make its delay del_ef;

2) Select one of the interference multipaths, and let its delay be del_int, where the interference multipath refers to the energy paths of other target users except the energy path of the selected target user and the energy paths of all interference users , all of which have inter-path interference to the selected multipath;

3) Generate a noise path to suppress interference from interfering multipath;

4) Select a part of the noise paths to participate in the final combination based on at least one criterion.

Preferably, the step of generating a noise path for suppressing multipath interference includes:

1) Select a multipath from the energy paths of the target user and the interference user as the reference multipath, and make its delay del_lp;

2) Obtain the delay del_nf of the target noise path according to the following mathematical formula:

del_nf = del_ef+order*(del_lp-del_int);

Among them, order is an integer greater than 0, indicating the order of the noise path.

Preferably, when order=1, and the reference multipath is the selected energy path, del_lp=del_ef, then the delay del_nf of the target noise path is obtained according to the following mathematical formula:

del_nf = 2*del_lp-del_int;

That is, the noise path del_nf and the interference multipath del_int are symmetrical to the selected energy path del_ef.

Preferably, the criteria include:

1) The noise path generated by the energy path with high energy is given priority;

2) The noise path generated by the interference path with high energy is given priority;

3) The noise path generated by the reference path with high energy is given priority;

4) The noise path with small order is given priority;

5) Only one of the two paths whose multipath delay interval is smaller than a certain threshold is selected.

It can be seen from the above-mentioned technical scheme of the present invention that, compared with the prior art, the selected multipath delay can better exert the performance of advanced receivers, suppress interference better, and improve the combination efficiency by using the method and device of the present invention. The final SINR (Signal to Interference plus Noise Ratio, Signal to Interference plus Noise Ratio) reduces the bit error rate of the receiver.

Description of drawings

Fig. 1 illustrates the general structure of the existing spread spectrum receiver, namely multipath delay selection and distribution, descrambling and despreading, multipath combining, decision decoding;

Figure 2 illustrates the module division of the device for selecting multipath delay provided by the embodiment of the present invention, which can be roughly divided into a target user multipath search module, an interfering user multipath search module, and a target user multipath delay selection module;

Fig. 3 illustrates the implementation process of the method for selecting multipath delay provided by the embodiment of the present invention, including the selection of energy path and the generation of noise path;

FIG. 4 illustrates a method flow for generating a noise path based on the principle of suppressing inter-path interference in an embodiment of the present invention;

Fig. 5 illustrates the generation process of the noise path in the embodiment of the present invention;

FIG. 6 illustrates a flow of a method for selecting multipath delay provided by Embodiment 1 of the present invention, in which noise paths are selected by sorting multipath energy;

FIG. 7 illustrates a flow of a method for selecting multipath delays provided by Embodiment 2 of the present invention. By assigning a weight to each noise path, a certain number of noise paths with higher weights are selected to participate in the final combination.

The realization of the purpose of the present invention, functional characteristics and excellent effects will be further described below in conjunction with specific embodiments and accompanying drawings.

Detailed ways

The technical scheme of the present invention will be described in further detail below in conjunction with the accompanying drawings and specific examples, so that those skilled in the art can better understand the present invention and implement it, but the examples given are not intended to limit the present invention .

In the present invention, multipath searches are performed on target users and interfering users respectively to obtain multipath related information. The target user here is the beneficiary user. Multipath search refers to the search for energy paths, which can be a correlation search based on known sequences. After multipath searching, the energy path information containing the energy of the target user signal and the energy path information containing the energy of the interference user signal are obtained. This patent proposes the multipath delay selection of the target user based on the energy path information of the target user and the interference user, and the selection result can be directly assigned to the multipath.

Since the multipath delay selection of the target user considers the energy path information of the interfering user, such multipath allocation enables the advanced receiver to suppress the energy of the interfering user purposefully and improve the demodulation performance of the target user. When the energy of interfering users accounts for a higher proportion of the total interference plus white noise, the gain of this method is more obvious.

A method for selecting multipath delay provided by an embodiment of the present invention includes the following steps:

S10. Perform multipath search on the target user and the interfering user respectively, to acquire multipath related information;

S20. Perform multipath delay selection of the target user according to the energy path information containing the energy of the target user signal and the energy path information of the interference user signal energy obtained through searching.

In this embodiment, in the step S10, the multipath search refers to the search for energy paths, and the multipath related information includes energy path delay and signal energy contained in each path.

In the step S20, the multipath delay selection of the target user includes selecting an energy path and selecting a noise path, which together constitute a finally selected multipath delay.

When performing the step S20, the energy path selection method includes:

S30. Select the energy path of the target user, and when the signal energy of the target user is less than a preset threshold, it may not be combined.

When performing the step S30, the noise path selection method includes:

S40. Select the noise path of the target user according to the principle of suppressing inter-multipath interference.

In this step S40, the step of selecting the noise path of the target user according to the principle of suppressing inter-multipath interference includes:

S401. Select an energy path of the target user as a potentially merged multipath, and set its delay to del_ef;

S402. Select one of the interference multipaths, and set its delay as del_int, wherein the interference multipath refers to the energy paths of other target users except the energy path of the selected target user and the energy paths of all interfering users , all of which have inter-path interference to the selected multipath;

S403. Generate a noise path to suppress interference from interfering multipaths;

S404. Select a part of noise paths to participate in the final combination based on at least one criterion.

In the step S403, the step of generating a noise path for suppressing interference from multipath interference includes:

S4031. Select a multipath from the energy paths of the target user and the interference user as the reference multipath, and set its delay as del_lp;

S4032. Obtain the delay del_nf of the target noise path according to the following mathematical formula:

del_nf = del_ef+order*(del_lp-del_int);

Among them, order is an integer greater than 0, indicating the order of the noise path.

Preferably, in the step S403, it also includes:

S4033. When order=1, and the reference multipath is the selected energy path, del_lp=del_ef, then obtain the delay del_nf of the target noise path according to the following mathematical formula:

del_nf = 2*del_lp-del_int;

That is, the noise path del_nf and the interference multipath del_int are symmetrical to the selected energy path del_ef.

In the step S404, the criteria include:

1) The noise path generated by the energy path with high energy is given priority;

2) The noise path generated by the interference path with high energy is given priority;

3) The noise path generated by the reference path with high energy is given priority;

4) The noise path with small order is given priority;

5) Only one of the two paths whose multipath delay interval is smaller than a certain threshold is selected.

For example, in a specific embodiment, the described target user multipath delay selection method includes the following specific steps:

Step 1: First, multipath search is performed on the target user and the interfering user to obtain corresponding energy path information.

Step 2: Perform multipath delay selection of the target user according to the energy path information of the target user and the interference user obtained in step 1. Target user multipath delay selection is divided into two parts, energy path selection and noise path selection, as shown in Figure 3, these two parts together constitute the final selected multipath delay.

Step 3: According to Step 2, select the energy path of the target user, and those whose energy is less than a certain preset threshold may not be merged.

Step 4: As shown in Figure 4, according to step 2, select the noise path of the target user according to the principle of suppressing inter-multipath interference. The specific steps are as follows:

Step 4a: Select an energy path of the target user as a potential merged multipath. Let the delay be del_ef. As shown in FIG. 5 , there are two energy paths for the target user and three energy paths for the interference user, and the serial number of the selected energy path is "1".

Step 4b: The energy paths of other target users except the selected energy path and the energy paths of all interfering users have inter-path interference to the selected multipath. One of these interfering multipaths is selected, and its delay is del_int, as shown in FIG. 5 , the serial number of the selected interfering path is "5".

Step 4c: Generate a noise path to suppress the interference of interfering multipath, for example, the generation method is as follows:

(1) Select a multipath from the energy paths of the target user and the interfering user as the reference multipath, and set its delay as del_lp, as shown in Figure 5, the serial number of the selected reference multipath is "3"

(2) The delay del_nf of the noise path is:

del_nf = del_ef+order*(del_lp-del_int) Formula 1;

Among them, order is an integer greater than 0, indicating the order of the noise path. As shown in Figure 5, order=1, the noise path with the sequence number "6" is generated.

(3) When order=1, the reference multipath is the selected energy path, that is, del_lp=del_ef, formula 1 degenerates to:

del_nf = 2*del_lp-del_int formula two;

That is, the noise path del_nf and the interference multipath del_int have a symmetrical relationship with respect to the selected energy path del_ef.

Step 4d: There will be many pairs of energy paths and interfering multipaths for potential merging, and there will be many noise paths generated. It is necessary to select a part of the noise paths to participate in the final merging based on certain criteria. The criteria are as follows:

1) The noise path generated by the energy path with high energy is given priority;

2) The noise path generated by the interference path with high energy is given priority;

3) The noise path generated by the reference path with high energy is given priority;

4) The noise path with small order is given priority;

5) Only one of the two paths whose multipath delay interval is smaller than a certain threshold is selected.

The embodiment of the present invention also provides a device for selecting multipath delay, including:

The target user multipath search module is used to perform multipath search on the target user to obtain multipath related information, wherein the multipath search refers to the search for energy paths, and the multipath related information includes energy path delay and each The signal energy contained in the bar diameter.

The interfering user multipath search module is used to perform multipath searching on the interfering user and obtain multipath related information;

The target user multipath delay selection module is configured to perform multipath delay selection of the target user according to the energy path information containing the energy of the target user signal and the energy path information of the interference user signal energy obtained through searching.

The multipath search module provides information for the multipath delay selection of the target user, including the energy path information of the target user and the interference user.

The multipath delay selection module of the target user comprehensively considers the energy path information of the target user and the interference user to select the multipath delay of the target user, so as to maximize the performance of the advanced receiver. Considering the energy path information of the target user and the interference user, the multipath delay of the target user is selected. If the selected multipath location contains the signal energy of the target user, it is an energy path, and if it does not contain it, it is a noise path. Both the energy path and the noise path need to be descrambled and despread, and finally symbols are combined according to a certain combination weight.

Specifically, the target user multipath delay selection module selects the target user's multipath delay including selecting an energy path and selecting a noise path, which together constitute the finally selected multipath delay.

The target user multipath delay selection module is also used to select the target user's energy path, and when the signal energy of the target user is less than a preset threshold, it may not be combined.

In addition, the target user multipath delay selection module is also used to select the target user's noise path according to the principle of suppressing inter-multipath interference.

Specifically, the step of selecting the target user's noise path according to the principle of suppressing inter-multipath interference by the target user multipath delay selection module includes:

1) Select an energy path of the target user as a potential merged multipath, and make its delay del_ef;

2) Select one of the interference multipaths, and let its delay be del_int, where the interference multipath refers to the energy paths of other target users except the energy path of the selected target user and the energy paths of all interference users , all of which have inter-path interference to the selected multipath;

3) Generate a noise path to suppress interference from interfering multipath;

4) Select a part of the noise paths to participate in the final combination based on at least one criterion.

Wherein, the step of generating a noise path for suppressing the interference of multipath interference includes:

1) Select a multipath from the energy paths of the target user and the interference user as the reference multipath, and make its delay del_lp;

2) Obtain the delay del_nf of the target noise path according to the following mathematical formula:

del_nf = del_ef+order*(del_lp-del_int);

Among them, order is an integer greater than 0, indicating the order of the noise path.

In specific implementation, when order=1 and the reference multipath is the selected energy path, del_lp=del_ef at this time, then the delay del_nf of the target noise path is obtained according to the following mathematical formula:

del_nf = 2*del_lp-del_int;

That is, the noise path del_nf and the interference multipath del_int are symmetrical to the selected energy path del_ef.

In addition, the criteria for selecting a part of noise paths to participate in the final combination include:

1) The noise path generated by the energy path with high energy is given priority;

2) The noise path generated by the interference path with high energy is given priority;

3) The noise path generated by the reference path with high energy is given priority;

4) The noise path with small order is given priority;

5) Only one of the two paths whose multipath delay interval is smaller than a certain threshold is selected.

Example 1:

As shown in Figure 6, it illustrates a method for multipath delay selection, selecting the noise path by sorting the multipath energy, including the following specific steps:

Step 1: Obtain the energy path information of the target user and the interfering user, including the energy path delay, the antenna to which it belongs, and the contained energy.

Step 2: Sort the multipaths according to the signal energy contained in the multipaths. The sorting here does not distinguish between users and antennas, and only sorts the energy from large to small. Of course, after sorting, a certain multipath belongs to the user and the antenna it belongs to needs to be one-to-one.

Step 3: Set the order as order. The higher the order, the worse the interference suppression effect of the noise path generated, so first search for the noise path with order=1, then search for the noise path with order=2, and so on.

Step 4: Select the energy path of the target user as a potential merged multipath according to the order of signal energy containing the target user from large to small, and record the multipath delay as del_ef.

Step 5: traverse all the multipaths on the antenna to which the combined multipath belongs according to the energy level, regard this multipath as an interference multipath, and record the multipath delay as del_int. The interference multipath can come from the target user or the interference user, and the interference multipath with high energy needs to be dealt with first.

Step 6: Use a certain multipath of the user to which the interference multipath belongs to suppress the interference multipath, and the delay of this reference path is denoted as del_lp. This path may be the maximum energy path of the user to which the interfering multipath belongs on the antenna, or the maximum energy path of the user to which the interfering multipath belongs, or other multipaths.

Step 7: Generate noise path delay del_nf according to Formula 1. The construction method of del_nf is not limited to this.

Step 8: Judge whether the generated noise path is effective or not based on certain principles. Preferably, if the number of selected multipaths reaches a certain number, the selection is not continued, and the selected noise path must be separated from the selected multipath delay by a certain distance.

Step 9: Exit the multipath delay selection module if the multipath delay selection exit condition is met, output the final multipath delay and distribute it to the descrambling and despreading unit. If it is not satisfied, continue to traverse the target user energy path, interference multipath and order order, and continue to search for other noise paths. The exit condition may be that the number of selected multipaths reaches a certain number.

Example 2:

As shown in Figure 7, it illustrates another method of multipath delay selection. By assigning a weight to each noise path, a certain number of noise paths with larger weights are selected to participate in the final combination, which specifically includes the following specific step:

Step 1: Obtain the energy path information of the target user and the interfering user, including the energy path delay, the antenna to which it belongs, and the contained energy.

Step 2: Set the order.

Step 3: Select one energy path from the target user, denote the delay as del_ef, and the multipath energy as eng_ef.

Step 4: Select one of the remaining target user energy paths and all interfering user energy paths as the interference multipath, the delay is del_int, and the energy is eng_int.

Step 5: Select the maximum energy path of the user to which the interference path belongs as the reference multipath, the delay is del_lp, and the energy is eng_lp.

Step 6: Generate the corresponding noise path delay as:

del_nf = del_ef+order*(del_lp-del_int), the weight is eng_ef*eng_int*eng_lp.

Step 7: Repeat steps 2 to 6 to generate all noise paths.

Step 8: Sort all noise paths according to their weights. If there are N energy paths for the target user, select the top N noise paths to participate in merging. If the distance between a noise path and the selected merged multipath is less than delta_t, delete the noise path.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related All technical fields are equally included in the scope of patent protection of the present invention.

Claims (12)

1. A method for selecting multipath delay, characterized in that, comprising: A. Perform multipath search on target users and interfering users respectively to obtain multipath related information; B. Perform multipath delay selection of the target user according to the energy path information containing the signal energy of the target user and the energy path information of the interference user signal energy obtained through searching; In step B, the multipath delay selection of the target user includes selecting an energy path and selecting a noise path, which together constitute the final selected multipath delay; Wherein, the method for selecting a noise path includes: D. Select the noise path of the target user according to the principle of suppressing inter-multipath interference; Wherein, the step of selecting the noise path of the target user according to the principle of suppressing inter-multipath interference includes: D1. Select an energy path of the target user as a potential merged multipath, and make its delay del_ef; D2. Select one of the interference multipaths, and let its delay be del_int, wherein the interference multipath refers to the energy paths of other target users except the energy path of the selected target user and the energy paths of all interference users , all of which have inter-path interference to the selected multipath; D3. Generate a noise path to suppress interference from interfering multipath; D4. Select a part of noise paths to participate in the final combination based on at least one criterion. 2. the method for selecting multipath delay as claimed in claim 1, is characterized in that, in described step A, described multipath search refers to the search to energy path, and described multipath related information comprises energy path delay and the signal energy contained in each path. 3. the method for selecting multipath delay as claimed in claim 1, is characterized in that, when performing described step B, energy path selection method comprises: C. Select the energy path of the target user. When the signal energy of the target user is less than a preset threshold, they may not be combined. 4. the method for selecting multipath delay as claimed in claim 1, is characterized in that, in described step D3, the step of generating a noise path in order to suppress the interference of interfering multipath comprises: D31. Select a multipath from the energy paths of the target user and the interference user as the reference multipath, and make its delay del_lp; D32. Obtain the delay del_nf of the target noise path according to the following mathematical formula: del_nf=del_ef+order*(del_lp-del_int); Among them, order is an integer greater than 0, indicating the order of the noise path. 5. the method for selecting multipath delay as claimed in claim 4, is characterized in that, in described step D3, also comprises: D33. When order=1, and the reference multipath is the selected energy path, del_lp=del_ef at this time, then the delay del_nf of the target noise path is obtained according to the following mathematical formula: del_nf=2*del_lp-del_int; That is, the noise path del_nf and the interference multipath del_int are symmetrical to the selected energy path del_ef. 6. the method for selecting multipath delay as claimed in claim 1, is characterized in that, in described step D4, described criterion comprises: 1) The noise path generated by the energy path with large energy is given priority; 2) The noise path generated by the interference path with high energy is given priority; 3) The noise path generated by the reference path with high energy is given priority; 4) The noise path with small order is given priority; 5) Only one of the two paths whose multipath delay interval is smaller than a certain threshold is selected. 7. A device for selecting multipath delay, comprising: The target user multipath search module is used to perform multipath search on the target user to obtain multipath related information; The interfering user multipath search module is used to perform multipath searching on the interfering user and obtain multipath related information; The target user multipath delay selection module is used to perform multipath delay selection of the target user according to the energy path information containing the target user signal energy and the energy path information of the interference user signal energy obtained through searching; Wherein, the multipath delay selection of the target user by the target user multipath delay selection module includes selecting an energy path and selecting a noise path, which together constitute the final selected multipath delay; The target user multipath delay selection module is also used to select the target user's noise path according to the principle of suppressing inter-multipath interference; Wherein, the step of selecting the target user's noise path according to the principle of suppressing inter-multipath interference by the target user multipath delay selection module includes: 1) Select an energy path of the target user as a potential merged multipath, and make its delay del_ef; 2) Select one of the interference multipaths, and let its delay be del_int, wherein the interference multipath refers to the energy paths of other target users except the energy path of the selected target user and the energy paths of all interference users , all of which have inter-path interference to the selected multipath; 3) Generate a noise path to suppress the interference of interfering multipath; 4) Select a part of the noise paths to participate in the final combination based on at least one criterion. 8. The device for selecting multipath delay according to claim 7, wherein said multipath search refers to a search for an energy path, and said multipath related information includes energy path delay and each path contained The magnitude of the signal energy. 9. The device for selecting multipath delay as claimed in claim 7, wherein the target user multipath delay selection module is also used to select the energy path of the target user, and when its signal energy is less than a preset threshold, It may not be merged. 10. The device for selecting multipath delay as claimed in claim 7, wherein the step of generating a noise path for suppressing the interference of interfering multipath comprises: 1) Select a multipath from the energy paths of the target user and the interference user as the reference multipath, and make its delay del_lp; 2) Obtain the delay del_nf of the target noise path according to the following mathematical formula: del_nf=del_ef+order*(del_lp-del_int); Among them, order is an integer greater than 0, indicating the order of the noise path. 11. The device for selecting multipath delay as claimed in claim 10, characterized in that, When order=1, and the reference multipath is the selected energy path, del_lp=del_ef at this time, then the delay del_nf of the target noise path is obtained according to the following mathematical formula: del_nf=2*del_lp-del_int; That is, the noise path del_nf and the interference multipath del_int are symmetrical to the selected energy path del_ef. 12. The device for selecting multipath delay as claimed in claim 7, wherein the criterion comprises: 1) The noise path generated by the energy path with large energy is given priority; 2) The noise path generated by the interference path with high energy is given priority; 3) The noise path generated by the reference path with high energy is given priority; 4) The noise path with small order is given priority; 5) Only one of the two paths whose multipath delay interval is smaller than a certain threshold is selected.