WO2018119939A1

WO2018119939A1 - Channel access method and device

Info

Publication number: WO2018119939A1
Application number: PCT/CN2016/113222
Authority: WO
Inventors: 李明; 遆光宇
Original assignee: 深圳天珑无线科技有限公司
Priority date: 2016-12-29
Filing date: 2016-12-29
Publication date: 2018-07-05

Abstract

Provided in the embodiment of the application are a channel access method and device. In one aspect, in the embodiment of the present application, obtaining a candidate spreading code by obtaining a spreading code used by a first system to identify a channel occupied by the first system; next, obtaining a target spreading code according to the candidate spreading code and the spreading code used by the first system, the target spreading code being used for identifying a channel among channels unoccupied by the first system that has the lowest interference on the communication of the first system; and, finally, instructing a second receiving end to access the channel corresponding to the target spreading code. Therefore, the technical solution provided in the embodiments of the present application can solve the problem of the low utilization rate of spectrum resources in a communication system in the prior art.

Description

Channel access method and device

Technical field

The present application relates to the field of communications technologies, and in particular, to a channel access method and apparatus.

Background technique

With the deepening of informatization, the amount of data in wireless communication has exploded, and the existing spectrum resources are becoming more and more tense. The method of resource allocation by using fixed frequency band division method can effectively allocate resources for different types of communication systems and users and avoid conflicts. However, in many divided frequency bands, the allocated spectrum resources have not been fully utilized. In most cases, the frequency band utilization of the static spectrum partitioning method is less than 10%. How to improve the utilization rate of existing spectrum resources is a technical problem that needs to be solved in the direction of improving communication efficiency.

Code Division Multiple Access (CDMA) is a wireless access technology widely used in the prior art. It is easy to implement due to its anti-interference, anti-fading, large capacity, soft handover and anti-spectrum analysis. In recent years, code division multiple access has been increasingly favored. In code division multiple access, the allocation of communication resources is realized by the allocation of spreading codes, and each user occupies a separate spreading code for establishing communication with the base station, in the code division multiple access downlink, The user's spreading code is orthogonal or nearly orthogonal, so that when receiving at the receiving end, the receiving end can effectively recover the transmitted signal as long as it knows the unique spreading code assigned.

In the process of implementing the present application, the inventors found that at least the following problems exist in the prior art:

In the prior art, many well-defined spectrum resources in a wireless communication system are not fully utilized, and the utilization rate of spectrum resources in the communication system is low.

Summary of the invention

In view of this, the embodiment of the present application provides a channel access method and device, which are used to solve the problem of low utilization of spectrum resources in the prior art communication system.

In one aspect, the embodiment of the present application provides a channel access method, which is applied to a communication system including a first system and a second system, where the first system includes a first receiving end and a first transmitting end, and the second system package The second receiving end and the second sending end are included; the method is performed on the second sending end, and includes:

Obtaining a spreading code used by the first system, where the spreading code is used to identify a channel occupied by the first system;

Obtaining a candidate spreading code;

And obtaining, by using the candidate spreading code and the spreading code used by the first system, a target spreading code, where the target spreading code is used to identify the first system that is not occupied by the first system. Signal with minimal interference to one channel;

Instructing the second receiving end to access a channel corresponding to the target spreading code.

The foregoing aspect and any possible implementation manner further provide an implementation manner of obtaining a candidate spreading code, including:

Obtaining an autocorrelation matrix of the second receiving end, and acquiring a multipath channel matrix between the second receiving end and the second sending end;

A candidate spreading code is obtained according to the autocorrelation matrix and the multipath channel matrix.

The foregoing aspect and any possible implementation manner further provide an implementation manner, where the candidate spreading code is obtained according to the autocorrelation matrix and the multipath channel matrix, and using the following formula:

q _i =arg max c ^T G ^H R ^-1 Gc

Where q _i is the _ith candidate spreading code in the candidate spreading code, i=1, 2...L,c represents a parameter, and at this time, c is a general spreading code, q _i ∈c, G is more The path channel matrix, R is the autocorrelation matrix, T is the transpose, and H is the conjugate transpose.

The aspect as described above, and any possible implementation manner, further provide an implementation manner of obtaining a target spreading code according to the candidate spreading code and the spreading code used by the first system, including:

Obtaining, by the second receiving end, a channel corresponding to each candidate spreading code, and a maximum interference value of the interference value caused by the first receiving end;

Obtaining, as the target spreading code, a spreading code corresponding to a smallest one of the largest interference values.

An aspect as described above and any possible implementation, further providing an implementation according to And the candidate spreading code and the spreading code used by the first system, and obtaining a channel corresponding to each candidate spreading code by the second receiving end by using the following formula, which is caused by the first receiving end Interference value:

Where J(c,q _i ) is the total mean squared correlation interference value of the i-th candidate spreading code for the first receiving end, M is the number of decomposable multipaths of the multipath channel, and c represents the parameter In this case, c is a general spreading code, q _i ∈ c, q _{i / l} represents a 1-bit cyclic right shift of the i-th candidate spreading code q _i , and T represents a transposition.

On the other hand, the embodiment of the present application provides a channel access apparatus, which is applied to a communication system including a first system and a second system, where the first system includes a first receiving end and a first transmitting end, and the second system includes a The second receiving end and the second sending end; the device is located on the second sending end, and includes:

a first obtaining unit, configured to obtain a spreading code used by the first system, where the spreading code is used to identify a channel occupied by the first system;

a second acquiring unit, configured to obtain a candidate spreading code;

a third obtaining unit, configured to obtain a target spreading code according to the candidate spreading code and a spreading code used by the first system, where the target spreading code is used to identify a channel that is not occupied by the first system A channel in which the signal interference of the first system is the smallest.

An access unit, configured to indicate that the second receiving end accesses a channel corresponding to the target spreading code.

The above-mentioned aspect and any possible implementation manner further provide an implementation manner, where the second obtaining unit is configured to:

The above-mentioned aspect and any possible implementation manner further provide an implementation manner, where the second obtaining unit is specifically configured to:

Deriving a candidate spreading code according to the autocorrelation matrix and the multipath channel matrix, and using the following formula:

q _i =arg max c ^T G ^H R ^-1 Gc

The aspect as described above and any possible implementation manner further provide an implementation manner, where the third obtaining unit is configured to:

And obtaining, according to the candidate spreading code and the spreading code used by the first system, a channel corresponding to each candidate spreading code that is accessed by the second receiving end, where the interference value caused by the first receiving end is a number of maximum interference values;

The above-mentioned aspect and any possible implementation manner further provide an implementation manner, where the third obtaining unit is specifically configured to:

And obtaining, according to the candidate spreading code and the spreading code used by the first system, a channel corresponding to each candidate spreading code by using the second receiving end, and causing the first receiving end Interference value:

Where J(c,q _i ) is the total mean squared correlation interference value of the i-th spreading code vector for the first receiving end, M is the number of decomposable multipaths of the multipath channel, and c represents the parameter In this case, c is a general spreading code, q _i ∈ c, q _i is a candidate spreading code, q _{i / l} represents a 1-bit cyclic right shift of the i-th candidate spreading code q _i , and T represents transposition.

One of the above technical solutions has the following beneficial effects:

The channel access method provided by the embodiment of the present application is applied to a communication system including a first system and a second system, where the first system includes a first receiving end and a first transmitting end, and the second system includes a second receiving end and a second a transmitting end; the method is performed on the second transmitting end, specifically, by obtaining the first system a spreading code, the spreading code is used to identify a channel occupied by the first system, and obtain a candidate spreading code, and then obtain a target spreading code according to the candidate spreading code and the spreading code used by the first system, and the target is expanded. The frequency code is used to identify a channel in the channel that is not occupied by the first system that has the least interference to the signal of the first system. Finally, the second receiving end is instructed to access the channel corresponding to the target spreading code. In the embodiment of the present application, the second sending end may obtain the spreading code used by the first system, and then the second sending end may determine a target extension for the second receiving end in the second system according to the current resource usage situation. The frequency code, the target spreading code is used to identify a channel in the unoccupied channel of the first system that has the least interference to the signal of the first system, so that the indication can be indicated without affecting the normal communication in the first system. The second receiving end accesses the channel corresponding to the target spreading code, which improves the frequency band utilization of the communication system. Therefore, the technical solution provided by the embodiment of the present application can solve the problem that the utilization rate of spectrum resources in the communication system in the prior art is low.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present application. One of ordinary skill in the art can also obtain other drawings based on these drawings without paying for inventive labor.

1 is a schematic diagram of a communication system in an embodiment of the present application;

2 is a schematic flowchart of Embodiment 1 of a channel access method according to an embodiment of the present application;

3 is a schematic flowchart of Embodiment 2 of a channel access method provided by an embodiment of the present application;

FIG. 4 is a functional block diagram of a channel access apparatus according to an embodiment of the present application.

detailed description

For a better understanding of the technical solutions of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

It should be understood that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present application without departing from the inventive scope are the scope of the present application.

The terms used in the embodiments of the present application are for the purpose of describing a particular embodiment only, and It is intended to limit the application. The singular forms "a", "the", and "the"

It should be understood that the term "and/or" as used herein is merely an association describing the associated object, indicating that there may be three relationships, for example, A and/or B, which may indicate that A exists separately, while A and B, there are three cases of B alone. In addition, the character "/" in this article generally indicates that the contextual object is an "or" relationship.

It should be understood that although the terms first, second, third, etc. may be used to describe a system or the like in the embodiments of the present application, these systems and the like should not be limited to these terms. These terms are only used to distinguish systems from each other. For example, the first system may also be referred to as a second system without departing from the scope of the embodiments of the present application. Similarly, the second system may also be referred to as a first system.

Depending on the context, the word "if" as used herein may be interpreted as "when" or "when" or "in response to determining" or "in response to detecting." Similarly, depending on the context, the phrase "if determined" or "if detected (conditions or events stated)" may be interpreted as "when determined" or "in response to determination" or "when detected (stated condition or event) "Time" or "in response to a test (condition or event stated)".

Embodiment 1

The embodiment of the present application provides a channel access method. The method is applied to a communication system including a first system and a second system, wherein the first system includes a first receiving end and a first transmitting end, and the second system includes a second receiving end and a second transmitting end.

It should be noted that, for convenience of description, the second receiving ends involved in the present application are all in a state to be accessed by the channel. In the actual application process, there may be z second receiving ends that have accessed the channel in the second system. The number of z is not particularly limited in this embodiment of the present application.

Specifically, please refer to FIG. 1 , which is a schematic diagram of a communication system in an embodiment of the present application. As shown in FIG. 1, the system includes a first system and a second system, where the first system includes one first transmitting end and K first receiving ends, and the second system includes one second transmitting end and one Second receiving end.

In the communication system shown in FIG. 1, the signal sent by the first transmitting end can be received by the first receiving end and the second receiving end in the communication system, which is indicated by a solid line in FIG. 1; the signal sent by the second transmitting end is shown in FIG. It can be received by the first receiving end and the second receiving end in the communication system, and is indicated by a broken line in FIG.

In the communication system shown in FIG. 1, in the first system, the K first receiving ends have established communication with the first transmitting end, that is, the first transmitting end allocates K devices to the K first receiving ends. The spreading code is not limited in this embodiment. The number of Ks is at least one.

In a specific implementation process, the first system may be the primary system and the second system may be the secondary system.

In another specific implementation, the communication system including the first system and the second system may be a code division multiple access communication system.

It can be understood that, in the communication system shown in FIG. 1, if any second receiving end accesses the channel, the communication between the newly accessed second receiving end and the second transmitting end is the first The communication between the first receiving end and the first sending end in the system generates signal interference. Therefore, the channel access method provided by the embodiment of the present application is to access the second receiving end after obtaining the channel occupied by the first system. A channel with minimal interference to the signal of the first system, so as to ensure normal communication between the first receiving end and the first transmitting end in the first system, and improve the utilization of spectrum resources in the communication system.

Based on the above concept, please refer to FIG. 2 , which is a schematic flowchart of Embodiment 1 of a channel access method according to an embodiment of the present application. As shown in FIG. 2 , the method includes the following steps:

S201. Obtain a spreading code used by the first system.

The spreading code is used to identify a channel occupied by the first system.

S202. Acquire a candidate spreading code.

S203. Obtain a target spreading code according to the candidate spreading code and the spreading code used by the first system.

The target spreading code is used to identify a channel in the channel that is not occupied by the first system that has the least interference to the signal of the first system.

S204. Instruct the second receiving end to access a channel corresponding to the target spreading code.

It should be noted that the execution body of S201-S204 may be a channel access device, and the device may be located at a second transmitting end in the communication system.

The technical solution of the embodiment of the present application has the following beneficial effects:

In the embodiment of the present application, the second sending end may obtain the spreading code used by the first system, and then the second sending end may determine a target extension for the second receiving end in the second system according to the current resource usage situation. The frequency code, the target spreading code is used to identify a channel in the unoccupied channel of the first system that has the least interference to the signal of the first system, so that the indication can be indicated without affecting the normal communication in the first system. The second receiving end accesses the channel corresponding to the target spreading code, which improves the frequency band utilization of the communication system. Therefore, the technical solution provided by the embodiment of the present application can solve the problem that the utilization rate of spectrum resources in the communication system in the prior art is low.

Embodiment 2

The method for obtaining the candidate spreading code in S202 is specifically described in the embodiment of the present application, based on the channel access method provided in the first embodiment.

In this embodiment, the number of the second receiving end in the second system is 1. In this case, only one second receiving end is in the state of the channel to be accessed. In this case, only the candidate corresponding to the second receiving end needs to be acquired. The frequency code can be.

In the second system, the second receiving end can obtain an autocorrelation matrix R related to its own wireless channel interference and noise. Therefore, when acquiring the autocorrelation matrix R of the second receiving end, the second transmitting end can directly The autocorrelation matrix R of the second receiving end is obtained in the second receiving end.

In a specific implementation process of acquiring the candidate spreading code, the autocorrelation matrix R of the second receiving end may be acquired, and the multipath channel matrix G between the second receiving end and the second transmitting end may be obtained, and then, according to The obtained autocorrelation matrix R and multipath channel matrix G obtain the candidate spreading code corresponding to the second receiving end.

To specifically describe the solution, the following implementation manners of obtaining a candidate spreading code are provided in the embodiment of the present application:

In the first implementation manner, according to the autocorrelation matrix R and the multipath channel matrix G, the candidate spreading code can be obtained according to the Rank-2 method by using the following formula:

q _i =arg max c ^T G ^H R ^-1 Gc

Where q _i is the _ith candidate spreading code in the candidate spreading code, j=1, 2...L,c represents a parameter, and at this time, c is a general spreading code, q _i ∈c, G is more The path channel matrix, R is the autocorrelation matrix, T is the transpose, and H is the conjugate transpose.

It should be noted that the candidate spreading code may include the spreading code used by the first system.

In addition, according to the autocorrelation matrix R, the multipath channel matrix G, and the obtained candidate spreading code vector, the transmit signal energy corresponding to the second receiving end can also be obtained:

Where P _i is the transmitted signal energy corresponding to the ith second receiving end, and γ is a parameter.

Embodiment 3

Based on the channel access method provided in the first embodiment, the method in the present application specifically describes the method for obtaining a target spreading code according to the candidate spreading code and the spreading code used by the first system in S203.

In the embodiment of the present application, the target spreading code is used to identify a channel that has the least interference to the signal of the first system in the channel that is not occupied by the first system. Therefore, it is necessary to select one target expansion among the candidate spreading codes. Frequency code, when the second receiving end accesses the channel corresponding to the target spreading code, The maximum interference value among the interference values caused by one receiving end is the smallest.

Based on this, acquiring the target spreading code may include the following steps:

Obtaining, according to the candidate spreading code and the spreading code used by the first system, a maximum interference value of the interference value caused by the first receiving end when the second receiving end accesses the channel corresponding to each candidate spreading code;

Obtaining a spreading code corresponding to the smallest one of the largest interference values as the target spreading code.

In a specific implementation process, according to the candidate spreading code and the spreading code used by the first system, and using the following formula, obtaining a channel corresponding to each candidate spreading code by the second receiving end, causing the first receiving end Interference value:

Where J(c,q _i ) is the total mean squared interference value of the ith candidate spreading code for the first receiving end, M is the number of decomposable multipaths of the multipath channel, and c is the parameter indicating the parameter In this case, c is a general spreading code, q _i ∈ c, q _{i / l} represents a 1-bit cyclic right shift of the i-th candidate spreading code q _i , and T represents a transposition.

It can be understood that when the number of the first receiving ends is K, it is assumed that the second receiving end accesses the channel corresponding to each candidate spreading code, which may cause interference to the K first receiving ends. The total mean squared interference value of K cycles corresponding to the spreading code. Moreover, considering that if the second receiving end accesses the channel corresponding to the different spreading code, the signal interference caused by the communication between the K first receiving ends and the first transmitting end is different, so in order to find a For a channel with the least interference to the signal in the first system, it is necessary to first determine some of the maximum interference values of the interference values caused by the second receiving end when accessing the channel corresponding to each candidate spreading code.

Based on this, if the number of candidate spreading codes is w, then w maximum interference values can be obtained, and then only a minimum interference value needs to be selected among the w maximum interference values, and the maximum interference value is obtained. The smallest spreading code is the target spreading code.

Further, when the second receiving end of the channel to be accessed is connected to the channel corresponding to the arbitrary spreading code, the transmitting signal energy P _i corresponding to the target spreading code can be obtained according to the method described in the second embodiment. Then, the channel corresponding to the target spreading code is used to transmit the signal energy P _i such that the second receiving end of the channel to be accessed accesses the designated channel.

Embodiment 4

Based on the channel access method provided in the foregoing Embodiment 1, the embodiment of the present application provides a specific implementation method of the foregoing channel access method.

Specifically, please refer to FIG. 3 , which is a schematic flowchart of Embodiment 2 of a channel access method according to an embodiment of the present application. As shown in FIG. 3, the method includes the following steps:

S301. Acquire an autocorrelation matrix obtained by the second receiving end, and obtain a multipath channel matrix between the second receiving end and the second transmitting end.

S302. Obtain a candidate spreading code set of the second receiving end by using the Rank-2 method according to the autocorrelation matrix and the multipath channel matrix.

S303. Obtain a maximum interference value of each candidate spreading code in the candidate spreading code set corresponding to each first receiving end.

S304. Determine a spreading code with a minimum interference value as the target spreading code.

S305. Instruct the second receiving end to access a channel corresponding to the target spreading code.

In this embodiment, the second sending end may obtain the spreading code used by the first system, and then the second sending end may determine, according to the current resource usage, the second receiving end in the second system. a target spreading code, the target spreading code is used to identify a channel in the unoccupied channel of the first system that has the least interference to the signal of the first system, so that the normal communication in the first system is not affected. And indicating that the second receiving end accesses the channel corresponding to the target spreading code, thereby improving the frequency band utilization of the communication system. Therefore, the technical solution provided by the embodiment of the present application can solve the problem that the utilization rate of spectrum resources in the communication system in the prior art is low.

Embodiment 5

Based on the channel access method provided in the first embodiment, the embodiment of the present application further provides an apparatus embodiment for implementing the steps and methods in the foregoing method embodiments.

The embodiment of the present application provides a channel access apparatus, which is applied to a communication system including a first system and a second system, where the first system includes a first receiving end and a first transmitting end, and the second system includes a communication system to be accessed. The second receiving end and the second transmitting end; the device is located on the second transmitting end.

Specifically, please refer to FIG. 4 , which is a functional block diagram of a channel access apparatus according to an embodiment of the present application. As shown in Figure 4, the device comprises:

a first obtaining unit 41, configured to obtain a spreading code used by the first system, where the spreading code is used to identify a channel occupied by the first system;

a second obtaining unit 42, configured to obtain a candidate spreading code;

The third obtaining unit 43 is configured to obtain a target spreading code according to the candidate spreading code and the spreading code used by the first system, where the target spreading code is used to identify a signal in the first system that is not occupied by the first system. One channel with the least interference.

The access unit 44 is configured to indicate that the second receiving end accesses the channel corresponding to the target spreading code.

Specifically, in the embodiment of the present application, the second obtaining unit 42 is configured to:

Obtaining an autocorrelation matrix of the second receiving end, and acquiring a multipath channel matrix between the second receiving end and the second transmitting end;

The candidate spreading code is obtained according to the autocorrelation matrix and the multipath channel matrix.

In a specific implementation process, the second obtaining unit 42 is specifically configured to:

According to the autocorrelation matrix and the multipath channel matrix, and using the following formula, the candidate spreading code is obtained:

q _i =arg max c ^T G ^H R ^-1 Gc

Specifically, in the embodiment of the present application, specifically, the third obtaining unit 43 is configured to:

In a specific implementation process, the third obtaining unit 43 is specifically configured to:

According to the candidate spreading code and the spreading code used by the first system, and using the following formula, obtain the interference value that the second receiving end accesses the channel corresponding to each candidate spreading code, and causes the first receiving end:

Where J(c,q _i ) is the total mean squared correlation interference value of the i-th spreading code for the first receiving end, M is the number of decomposable multipaths of the multipath channel, and c represents the parameter. , c is a general spreading code, q _i ∈ c, q _i is a candidate spreading code, q _{i / l} represents a 1-bit cyclic right shift of the i-th candidate spreading code q _i , and T represents transposition.

Since the units in this embodiment can perform the method shown in FIG. 2, and the parts not described in detail in this embodiment, reference may be made to the related description of FIG. 2.

In the embodiment of the present application, the second sending end may obtain the spreading code used by the first system, and then the second sending end may determine a target extension for the second receiving end in the second system according to the current resource usage situation. The frequency code, the target spreading code is used to identify a channel in the unoccupied channel of the first system that has the least interference to the signal of the first system, so that the indication can be indicated without affecting the normal communication in the first system. The second receiving end accesses the channel corresponding to the target spreading code, which improves the frequency band utilization of the communication system. Therefore, the technical solution provided by the embodiment of the present application can solve the communication system in the prior art. The problem of low utilization of spectrum resources.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner. For example, multiple units or components may be combined. Or it can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of hardware plus software functional units.

The above-described integrated unit implemented in the form of a software functional unit can be stored in a computer readable storage medium. The software functional unit is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to perform the methods of the various embodiments of the present application. Part of the steps. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like, which can store program codes. .

The above is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc., which are made within the spirit and principles of the present application, should be included in the present application. Within the scope of protection.

Claims

A channel access method is characterized in that it is applied to a communication system including a first system and a second system, the first system includes a first receiving end and a first transmitting end, and the second system includes a second receiving end and a second a sending end; the method is performed on the second sending end, and includes:

Obtaining a spreading code used by the first system, where the spreading code is used to identify a channel occupied by the first system;

Obtaining a candidate spreading code;

And obtaining, by using the candidate spreading code and the spreading code used by the first system, a target spreading code, where the target spreading code is used to identify the first system that is not occupied by the first system. Signal with minimal interference to one channel;

Instructing the second receiving end to access a channel corresponding to the target spreading code.
The method according to claim 1, wherein when the number of the second receiving ends is 1, obtaining a candidate spreading code comprises:

Obtaining an autocorrelation matrix of the second receiving end, and acquiring a multipath channel matrix between the second receiving end and the second sending end;

A candidate spreading code is obtained according to the autocorrelation matrix and the multipath channel matrix.
The method according to claim 2, wherein the candidate spreading code is obtained according to the autocorrelation matrix and the multipath channel matrix, and using the following formula:

q i =arg maxc T G H R -1 Gc

Where q i is the ith candidate spreading code in the candidate spreading code, i=1, 2...L,c represents a parameter, and at this time, c is a general spreading code, q i ∈c, G is more The path channel matrix, R is the autocorrelation matrix, T is the transpose, and H is the conjugate transpose.
The method according to claim 1, wherein the target spreading code is obtained according to the candidate spreading code and the spreading code used by the first system, including:

Obtaining the second receiving end according to the candidate spreading code and the spreading code used by the first system And a channel, a channel corresponding to each candidate spreading code, and a maximum interference value of the interference value caused by the first receiving end;

Obtaining, as the target spreading code, a spreading code corresponding to a smallest one of the largest interference values.
The method according to claim 4, wherein the second receiving end accesses each candidate spread spectrum according to the candidate spreading code and the spreading code used by the first system, and using the following formula The interference value caused by the channel corresponding to the code to the first receiving end:

Where J(c,q i ) is the total mean squared correlation interference value of the i-th candidate spreading code for the first receiving end, M is the number of decomposable multipaths of the multipath channel, and c represents the parameter In this case, c is a general spreading code, q i ∈ c, q i / l represents a 1-bit cyclic right shift of the i-th candidate spreading code q i , and T represents a transposition.
A channel access device is characterized in that it is applied to a communication system including a first system and a second system, the first system includes a first receiving end and a first transmitting end, and the second system includes a second receiving end and a second a sending end; the device is located on the second sending end, and includes:

a first obtaining unit, configured to obtain a spreading code used by the first system, where the spreading code is used to identify a channel occupied by the first system;

a second acquiring unit, configured to obtain a candidate spreading code;

a third obtaining unit, configured to obtain a target spreading code according to the candidate spreading code and a spreading code used by the first system, where the target spreading code is used to identify a channel that is not occupied by the first system a channel in which the signal interference of the first system is the smallest;

An access unit, configured to indicate that the second receiving end accesses a channel corresponding to the target spreading code.
The device according to claim 6, wherein the second obtaining unit is configured to:

Obtaining an autocorrelation matrix of the second receiving end, and acquiring a multipath channel matrix between the second receiving end and the second sending end;

A candidate spreading code is obtained according to the autocorrelation matrix and the multipath channel matrix.
The device according to claim 7, wherein the second obtaining unit is specifically configured to:

Deriving a candidate spreading code according to the autocorrelation matrix and the multipath channel matrix, and using the following formula:

q i =arg maxc T G H R -1 Gc

Where q i is the ith candidate spreading code in the candidate spreading code, i=1, 2...L,c represents a parameter, and at this time, c is a general spreading code, q i ∈c, G is more The path channel matrix, R is the autocorrelation matrix, T is the transpose, and H is the conjugate transpose.
The device according to claim 6, wherein the third obtaining unit is configured to:

Obtaining, in the interference value caused by the first receiving end, when the second receiving end accesses the channel corresponding to each candidate spreading code according to the candidate spreading code and the spreading code used by the first system Some of the maximum interference values;

Obtaining, as the target spreading code, a spreading code corresponding to a smallest one of the largest interference values.
The device according to claim 9, wherein the third obtaining unit is specifically configured to:

And obtaining, according to the candidate spreading code and the spreading code used by the first system, a channel corresponding to each candidate spreading code by using the second receiving end, and causing the first receiving end Interference value:

Where J(c,q i ) is the total mean squared correlation interference value of the i-th spreading code for the first receiving end, M is the number of decomposable multipaths of the multipath channel, and c is a parameter. In this case, c is a general spreading code, q i ∈ c, q i is a candidate spreading code, q i / l represents a 1-bit cyclic right shift of the i-th candidate spreading code q i , and T represents a transposition.