CN106301465A - A kind of method and device eliminating co-channel full duplex system self-interference - Google Patents

Abstract

The present invention provides a method and device for eliminating self-interference in a same-frequency full-duplex system. The method includes: establishing a link with a terminal with registration authority; Frequency code, wherein, the dedicated downlink spreading code is different from the dedicated uplink spreading code; using the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with a terminal with registration authority. In the solution of the present invention, the interference randomization method is used to spread the signal of the transmission link, so that the in-band modulation interference of the transmission link is white-noised, and the self-interference in the same-frequency full-duplex communication is eliminated.

Description

A method and device for eliminating self-interference in a same-frequency full-duplex system

technical field

The invention relates to the field of communication technology, in particular to a method and device for eliminating self-interference in a same-frequency full-duplex system.

Background technique

In a wireless communication system, duplex refers to how the communication parties perform two-way information exchange, which can be divided into simplex, half-duplex and full-duplex. Simplex means that data can only be transmitted in one direction. Among the two parties in communication, one is fixed as the sender, and the other is fixed as the receiver. Information can only be transmitted in one direction, using a single transmission line. A half-duplex system allows two-way data transmission between two devices, but not simultaneously. Therefore, only one device is allowed to transmit data at the same time. If another device wants to transmit data, it needs to wait for the original device to transmit data to complete the transmission before processing. A full-duplex system allows two-way data transmission between two devices at the same time. Two full-duplex modes currently exist are time-division duplex and frequency-division duplex, but neither can realize full-duplex communication at the same time and at the same frequency, and the spectrum efficiency is relatively low.

In order to make full use of precious spectrum resources and maximize spectrum efficiency and system capacity, it is an important direction to develop a same-frequency full-duplex system. However, the problem faced by the same-frequency full-duplex communication is that there will be strong self-interference, which leads to difficulties in the demodulation between the terminal and the base station, that is, the transmission of the communication device itself will interfere with its own reception, thus limiting the same-frequency full-duplex Promoted and applied.

In addition, the current solution to the problem of self-interference mainly focuses on how to reconstruct and eliminate the self-transmitted signal in the receiving chain. The problem with this method is that it is difficult to reconstruct its own transmission signal accurately, as shown in Figure 1, because the source of the self-interference signal includes not only the interference from the transmission signal leaked to the receiving link through the RF front-end, but also the interference from the antenna radiated to the receiving link. The space is interfered by the equipment received, and because the space information is beyond the control of the equipment, the equipment cannot know the above interference exactly. Therefore, it is very poor to hope to reconstruct the transmitted signal to eliminate the interference to the reception.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method and device for eliminating self-interference in the same-frequency full-duplex system, by using different dedicated uplink spreading codes and dedicated downlink spreading codes to spread and decompose uplink signals and downlink signals Spread spectrum, so that the self-interference of communication equipment can be eliminated.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

According to one aspect of the present invention, a method for eliminating self-interference in a same-frequency full-duplex system is provided, which is applied to the base station side, and the method includes:

Establish a link with a terminal with registration authority;

Negotiating with the terminal with registration authority a dedicated uplink spreading code and a dedicated downlink spreading code, wherein the dedicated downlink spreading code is different from the dedicated uplink spreading code;

Using the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the terminal with registration authority.

Among them, establishing a link with a terminal with registration authority includes:

Broadcast the system information of the serving cell where the base station is located, the system information includes the frequency, bandwidth, uplink and downlink time slot ratio used by the serving cell, and the public uplink spreading code and downlink spreading code used to access the terminal with registration authority. frequency code;

Judging whether the frequency band, bandwidth, and uplink and downlink time slot ratio used by a terminal are the same as the frequency, bandwidth, and uplink and downlink time slot ratio used by the serving cell; A terminal with authorization establishes a link, and receives a registration request message sent by the terminal with registration authorization according to the public uplink spreading code and downlink spreading code, wherein the registration request message includes the uplink spreading code used by the terminal. frequency code and downlink spreading code.

Wherein, negotiating a dedicated uplink spreading code and a dedicated downlink spreading code with the terminal having the registration authority is specifically:

According to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal with registration authority, negotiate with the terminal with registration authority to obtain a dedicated uplink Spreading code and dedicated downlink spreading code.

Wherein, using the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the terminal having the registration authority, specifically includes:

Spreading the downlink signal by using the dedicated downlink spreading code to obtain the spread downlink signal, and sending it to the terminal with registration authority;

receiving the self-interference signal generated during the process of sending the spread downlink signal, and the uplink signal spread by the terminal with registration authority using the dedicated uplink spread code;

Despreading the self-interference signal and the spread uplink signal by using the dedicated uplink spreading code, and selecting the uplink signal from received signals.

Wherein, the downlink signal is spread by using the dedicated downlink spreading code, specifically:

The downlink signal is multiplied or added to the dedicated downlink spreading code to obtain the downlink signal after spreading.

Wherein, using the dedicated uplink spreading code to despread the self-interference signal and the spread uplink signal, specifically:

The self-interference signal and the uplink signal after spectrum spreading are respectively multiplied or added to the dedicated uplink spreading code.

According to another aspect of the present invention, a method for eliminating self-interference in a same-frequency full-duplex system is provided, which is applied to the terminal side, and the method includes:

establishing a link with a base station allowing said terminal to register;

Negotiating a dedicated uplink spreading code and a dedicated downlink spreading code with the base station that allows the terminal to register, wherein the dedicated uplink spreading code is different from the dedicated downlink spreading code;

performing same-frequency full-duplex communication with the base station allowing the terminal to register by using the dedicated uplink spreading code and the dedicated downlink spreading code.

Wherein, establishing a link with a base station that allows the terminal to register specifically includes:

Acquiring the system information broadcast by a base station of the serving cell where the base station is located, the system information including the frequency, bandwidth, uplink and downlink time slot ratio used by the serving cell, and the common uplink spreading code and downlink spreading code used by the access terminal. frequency code;

Judging whether the frequency band, bandwidth, and uplink-downlink time slot ratio used by the serving cell are the same as those used by the terminal, if they are the same, obtain a base station that allows the terminal to register, and obtain a base station that allows the terminal to register. The base station that allows the terminal to register establishes a link, and sends a registration request message to the base station that allows the terminal to register according to the public uplink spreading code and downlink spreading code, wherein the registration request message includes the The uplink spreading code and the downlink spreading code used by the terminal.

Wherein, negotiating a dedicated uplink spreading code and a dedicated downlink spreading code with the base station that allows the terminal to register is specifically:

Negotiate with the base station that allows the terminal to register according to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal, to obtain a dedicated uplink spreading code code and dedicated downlink spreading code.

Wherein, using the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the base station that allows the terminal to register, specifically includes:

Spreading the uplink signal by using the dedicated uplink spreading code to obtain the spread uplink signal, and sending it to the base station that allows the terminal to register;

receiving the self-interference signal generated during the process of sending the spread uplink signal, and the downlink signal spread by the base station allowing the terminal to register by using the dedicated downlink spread code;

Despreading the self-interference signal and the spread downlink signal by using the dedicated downlink spreading code, and selecting the downlink signal from received signals.

Wherein, using the dedicated uplink spreading code to spread the uplink signal is specifically:

The uplink signal is multiplied or added to the dedicated uplink spreading code to obtain a spread uplink signal.

Wherein, using the dedicated downlink spreading code to despread the self-interference signal and the spread downlink signal, specifically:

The self-interference signal and the downlink signal after spreading are respectively multiplied or added to the dedicated downlink spreading code.

According to another aspect of the present invention, a device for eliminating self-interference in a same-frequency full-duplex system is also provided, which is applied to a base station, and the device includes:

A first link module, configured to establish a link with a terminal with registration authority;

A first negotiating module, configured to negotiate with the terminal having registration authority a dedicated uplink spreading code and a dedicated downlink spreading code, wherein the dedicated downlink spreading code is different from the dedicated uplink spreading code;

The first communication module is configured to use the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the terminal with registration authority.

Wherein, the first link module includes:

The broadcast unit is used to broadcast the system information of the serving cell where the base station is located. The system information includes the frequency, bandwidth, uplink and downlink time slot ratio used by the serving cell, and the public uplink extension used to access the terminal with registration authority. Frequency code and downlink spreading code;

A linking unit, used to determine whether the frequency, bandwidth, and uplink-downlink time slot ratio used by a terminal are the same as the frequency band, bandwidth, and uplink-downlink time slot ratio used by the serving cell, and if they are the same, obtain a terminal with registration authority, Establishing a link with the terminal with registration authority, and receiving a registration request message sent by the terminal with registration authority according to the public uplink spreading code and downlink spreading code, wherein the registration request message includes the Uplink spreading code and downlink spreading code used by terminals with registration authority.

Wherein, the first negotiation module is specifically used for:

According to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal with registration authority, negotiate with the terminal with registration authority to obtain a dedicated uplink Spreading code and dedicated downlink spreading code.

Wherein, the first communication module includes:

A downlink spreading unit, configured to spread the downlink signal by using the dedicated downlink spreading code, obtain the spread downlink signal, and send it to the terminal with registration authority;

The first receiving unit is configured to receive the self-interference signal generated during the process of sending the spread downlink signal, and the uplink signal spread by the terminal with registration authority using the dedicated uplink spreading code ;

The first despreading unit is configured to despread the self-interference signal and the spread uplink signal by using the dedicated uplink spreading code, and select the uplink signal from received signals.

Wherein, the downlink spreading unit is specifically configured to: multiply or add the downlink signal to the dedicated downlink spreading code to obtain a downlink signal after spreading.

Wherein, the first despreading unit is specifically used for:

The self-interference signal and the uplink signal after spectrum spreading are respectively multiplied or added to the dedicated uplink spreading code.

According to another aspect of the present invention, a device for eliminating self-interference in a same-frequency full-duplex system is also provided, which is applied to a terminal, and the device includes:

A second link module, configured to establish a link with a base station that allows the terminal to register;

The second negotiation module is configured to negotiate a dedicated uplink spreading code and a dedicated downlink spreading code with a base station that allows the terminal to register, wherein the dedicated uplink spreading code is different from the dedicated downlink spreading code;

The second communication module is configured to use the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the base station that allows the terminal to register.

Wherein, the second link module includes:

An acquisition unit, configured to acquire system information broadcast by a base station of the serving cell where the base station is located, where the system information includes the frequency, bandwidth, uplink and downlink time slot ratio used by the serving cell, and the public uplink extension used by the access terminal. Frequency code and downlink spreading code;

The second linking unit is used to determine whether the frequency band, bandwidth, and uplink-downlink time slot ratio used by the serving cell are the same as those used by the terminal, and if they are the same, obtain permission The base station where the terminal is registered, establishes a link with the base station that allows the terminal to register, and sends a registration request message to the base station that allows the terminal to register according to the common uplink spreading code and downlink spreading code, wherein, The registration request message includes an uplink spreading code and a downlink spreading code used by the terminal.

The second negotiation module is specifically used for:

Negotiate with the base station that allows the terminal to register according to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal, to obtain a dedicated uplink spreading code code and dedicated downlink spreading code.

Wherein, the second communication module includes:

An uplink spreading unit, configured to use the dedicated uplink spreading code to spread the uplink signal, obtain the spread uplink signal, and send it to the base station that allows the terminal to register;

The second receiving unit is configured to receive the self-interference signal generated during the process of sending the spread uplink signal, and the self-interference signal after the base station that allows the terminal to register uses the dedicated downlink spread code to spread the spectrum downlink signal;

The second despreading unit is configured to despread the self-interference signal and the spread downlink signal by using the dedicated downlink spreading code, and select the downlink signal from received signals.

Wherein, the uplink spreading unit is specifically used for:

The uplink signal is multiplied or added to the dedicated uplink spreading code to obtain a spread uplink signal.

Wherein, the second despreading unit is specifically used for:

The self-interference signal and the downlink signal after spreading are respectively multiplied or added to the dedicated downlink spreading code.

The beneficial effects of the present invention are:

In the method for eliminating self-interference of the same-frequency full-duplex system in the embodiment of the present invention, after the base station and the terminal establish a link, according to the common uplink spreading code and downlink spreading code of the base station and the uplink spreading code and downlink spreading code used by the terminal The codes are negotiated to obtain different dedicated uplink spreading codes and dedicated downlink spreading codes.

In the same-frequency full-duplex communication process, on the base station side, the base station uses a dedicated downlink spreading code to spread the downlink signal, and uses a dedicated uplink spreading code to despread the received self-interference signal and the uplink signal sent by the terminal, so that The self-interference signal after despreading shows white noise characteristics, and the uplink signal after despreading shows signal peak characteristics, so that the uplink signal is selected from the self-interference signal of the base station.

On the terminal side, the terminal uses a dedicated uplink spreading code to spread the uplink signal, and uses a dedicated downlink spreading code to despread the received self-interference signal and downlink signal, so that the self-interference signal after despreading shows white noise characteristics, The downlink signal after despreading exhibits signal peak characteristics, so that the downlink signal is selected from the self-interference signal of the terminal.

Description of drawings

FIG. 1 shows a schematic diagram of the principle of a self-interference reconstruction elimination method in the prior art;

FIG. 2 shows a schematic flowchart of a method for eliminating self-interference in a same-frequency full-duplex system applied to the base station side according to an embodiment of the present invention;

FIG. 3 shows a schematic flowchart of a method for eliminating self-interference in a same-frequency full-duplex system applied to a terminal side according to an embodiment of the present invention;

FIG. 4 shows a structural block diagram of a device for eliminating self-interference in a same-frequency full-duplex system applied to the base station side according to an embodiment of the present invention;

Fig. 5 shows the structural block diagram of the first link module of the embodiment of the present invention;

Fig. 6 shows the structural block diagram of the first communication module of the embodiment of the present invention;

FIG. 7 shows a structural block diagram of a device for eliminating self-interference in a same-frequency full-duplex system applied to a terminal side according to an embodiment of the present invention;

Fig. 8 shows the structural block diagram of the second link module of the embodiment of the present invention;

Fig. 9 shows the structural block diagram of the second communication module of the embodiment of the present invention;

Fig. 10 represents the power spectral density diagram before signal spreading;

The power spectral density diagram after signal spreading in Fig. 11;

Fig. 12 represents the power spectral density diagram after signal despreading;

FIG. 13 shows a single-antenna terminal architecture diagram of an embodiment of the present invention;

FIG. 14 shows a diagram of a dual-antenna terminal architecture according to an embodiment of the present invention.

detailed description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided for more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

Embodiment one

According to an aspect of the embodiments of the present invention, a method for eliminating self-interference in a same-frequency full-duplex system is provided, which is applied to the base station side. The method first establishes a link with a terminal with registration authority; then, establishes a link with the terminal with registration authority. A terminal with registration authority negotiates a dedicated uplink spreading code and a dedicated downlink spreading code; finally, uses the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the terminal with registration authority .

The method for eliminating the self-interference of the same-frequency full-duplex system in the embodiment of the present invention uses different dedicated uplink spreading codes and dedicated downlink spreading codes to carry out same-frequency full-duplex communication, which can eliminate the self-interference generated while transmitting signals Eliminate, and successfully obtain the uplink signal sent by the terminal.

As shown in Figure 2, the method includes:

Step S21, establishing a link with a terminal with registration authority.

Wherein, when the base station and the terminal perform same-frequency full-duplex communication, it is necessary to determine whether the terminal has the registration authority, and establish a link with the terminal having the registration authority.

Specifically, the base station will broadcast the system information of the serving cell, so that the terminal can judge whether it has the registration right by obtaining the system information, wherein the system information includes the frequency, bandwidth, and uplink and downlink time slot allocation used by the serving cell. ratio and the common uplink spreading code and downlink spreading code used by the access terminal;

When the frequency band, bandwidth, and uplink-downlink time slot ratio used by a terminal are the same as the frequency, bandwidth, and uplink-downlink time slot ratio used by the serving cell, the terminal has the registration authority, and the base station has the registration authority The terminal establishes a link, and receives the request registration message sent by the terminal according to the common uplink spreading code and downlink spreading code, wherein the request registration message includes the uplink spreading code and downlink spreading code used by the terminal frequency code.

Step S23, negotiating with the terminal having the registration authority a dedicated uplink spreading code and a dedicated downlink spreading code.

Wherein, the dedicated uplink spreading code is different from the dedicated downlink spreading code.

Since the base station itself has a common uplink spreading code and downlink spreading code for terminal access, and the terminal also has its own uplink spreading code and downlink spreading code, so the communication between the base station and the terminal with registration authority In the same-frequency full-duplex communication, it is necessary to obtain a dedicated uplink spreading code and a dedicated downlink spreading code through negotiation, and in order to eliminate the self-interference generated by the base station and the terminal in the process of transmitting signals, different dedicated uplink spreading codes need to be used. Spreading code and dedicated downlink spreading code.

Therefore, step S23 is specifically:

According to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal with registration authority, negotiate with the terminal with registration authority to obtain a dedicated uplink spreading code Frequency code and dedicated downlink spreading code.

Step S25, using the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the terminal with registration authority.

Wherein, step S25 specifically includes:

Spreading the downlink signal by using the dedicated downlink spreading code to obtain the spread downlink signal, and sending it to the terminal with registration authority;

receiving the self-interference signal generated during the process of sending the spread downlink signal, and the uplink signal spread by the terminal with registration authority using the dedicated uplink spread code;

Despreading the self-interference signal and the spread uplink signal by using the dedicated uplink spreading code, and selecting the uplink signal from received signals.

In the method for eliminating self-interference of the same-frequency full-duplex system in the embodiment of the present invention, on the base station side, when the base station needs to send the uplink signal to the terminal, the uplink signal is spread by using a dedicated downlink spreading code. The downlink signal received by the base station is also the signal after the terminal with the registration authority spreads the spectrum with the dedicated downlink spreading code, but the signal received by the base station includes not only the uplink signal after the spread spectrum, but also the base station with the registration authority. Self-interference signals generated during the transmission of uplink signals. When the base station uses a dedicated uplink spreading code to despread the received signal, the self-interference signal exhibits white noise characteristics, and the uplink signal exhibits a peak characteristic, thereby selecting the uplink signal from the received signal.

The principle is shown in Figures 10-12. Since the dedicated uplink spreading code and the dedicated downlink spreading code are different, according to the characteristics of the spreading code, when the same spreading code is used for spreading and despreading, the signals are completely correlated. The demodulation power presents a peak value, and when the spreading codes of spreading and despreading are different, the signal presents the characteristic of white noise. Therefore, in the method of the present invention, since the uplink and downlink adopt different spreading codes to spread spectrum, the downlink signal transmitted by the base station is despreaded with a dedicated uplink spreading code after being received by the base station, because the uplink and downlink spreading codes are different After the despreading, the power spectrum still exhibits white noise characteristics, and the useful downlink signal is despread by the dedicated downlink spreading code, showing a signal peak and can be normally demodulated. Therefore, this method can avoid the interference of transmission to reception in the case of full-duplex at the same frequency, and no matter whether the downlink signal transmitted by the base station reaches the receiving link through radio frequency leakage or is received by the base station after being radiated by the antenna, this method can Realize the randomization of interference without affecting reception.

Wherein, the downlink signal is spread by using the dedicated downlink spreading code, specifically:

The downlink signal is multiplied or added to the dedicated downlink spreading code to obtain the downlink signal after spreading.

Using the dedicated uplink spreading code to despread the self-interference signal and the spread uplink signal, specifically:

The self-interference signal and the uplink signal after spectrum spreading are respectively multiplied or added to the dedicated uplink spreading code.

In the method for eliminating self-interference of the same-frequency full-duplex system in the embodiment of the present invention, the downlink signal sent by the base station and the uplink signal received are a series of binary numbers, and the dedicated spread spectrum code also belongs to the binary sequence code, and the spread spectrum process is It is a process of multiplying or adding the binary digital signal and the binary sequence code, and the despreading is also to multiply or add the spread signal and the above binary sequence code.

Embodiment two

According to another aspect of the embodiments of the present invention, there is also provided a method for eliminating self-interference in the same-frequency full-duplex system, which is applied to the terminal side. The method first: establishes a link with a base station that allows the terminal to register; then, Negotiating a dedicated uplink spreading code and a dedicated downlink spreading code with the base station that allows the terminal to register; finally, using the dedicated uplink spreading code and the dedicated downlink spreading code to communicate with the base station that allows the terminal to register The base station performs same-frequency full-duplex communication.

As shown in Figure 3, the method includes:

Step S31, establishing a link with a base station that allows the terminal to register.

Wherein, step S31 specifically includes:

Acquiring the system information broadcast by a base station of the serving cell where the base station is located, the system information including the frequency, bandwidth, uplink and downlink time slot ratio used by the serving cell, and the common uplink spreading code and downlink spreading code used by the access terminal. frequency code;

Judging whether the frequency band, bandwidth, and uplink-downlink time slot ratio used by the terminal are the same as the frequency, bandwidth, and uplink-downlink time slot ratio used by the serving cell, if they are the same, obtain a base station that allows the terminal to register, and use the The base station that allows the terminal to register establishes a link, and sends a registration request message to the base station that allows the terminal to register according to the public uplink spreading code and downlink spreading code, wherein the registration request message includes the The uplink spreading code and the downlink spreading code used by the terminal.

In the method for eliminating self-interference of the same-frequency full-duplex system in the embodiment of the present invention, on the terminal side, when the same-frequency full-duplex communication between the terminal and the base station is required, the terminal needs to establish a link with the base station, and the base station allows The terminal registers. After the terminal establishes a link with the base station, the terminal reports the uplink spreading code and downlink spreading code used by itself to the base station, so as to facilitate subsequent negotiation with the base station.

Step S33, negotiating with the base station that allows the terminal to register a dedicated uplink spreading code and a dedicated downlink spreading code

frequency code. Wherein, the dedicated uplink spreading code is different from the dedicated downlink spreading code.

Wherein, step S33 is specifically:

Negotiate with the base station that allows the terminal to register according to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal, to obtain a dedicated uplink spreading code code and dedicated downlink spreading code.

Step S35, using the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the base station.

Wherein, step S35 specifically includes:

Spreading the uplink signal by using the dedicated uplink spreading code to obtain the spread uplink signal, and sending it to the base station that allows the terminal to register;

receiving the self-interference signal generated during the process of sending the spread uplink signal, and the downlink signal spread by the base station allowing the terminal to register by using the dedicated downlink spread code;

Despreading the self-interference signal and the spread downlink signal by using the dedicated downlink spreading code, and selecting the downlink signal from received signals.

Wherein, using the dedicated uplink spreading code to spread the uplink signal is specifically:

The uplink signal is multiplied or added to the dedicated uplink spreading code to obtain a spread uplink signal.

Wherein, using the dedicated downlink spreading code to despread the self-interference signal and the spread downlink signal, specifically:

The self-interference signal and the downlink signal after spreading are respectively multiplied or added to the dedicated downlink spreading code.

The principle of spreading and despreading on the terminal side is the same as that on the base station side. Also as shown in Figures 10-12, after the signal is spread, the power spectral density of the signal is pulled down, which is beneficial to the signal When the spread spectrum is transmitted in the channel, and when the spread spectrum signal is despread by the same special spread spectrum code, the power spectral density of the signal is accumulated and becomes stronger, but the power spectral density of the noise remains unchanged. Therefore, the method for eliminating self-interference in the same-frequency full-duplex system in the embodiment of the present invention can avoid the interference of transmission to reception in the case of same-frequency full-duplex, and regardless of whether the uplink signal transmitted by the terminal reaches the receiving link through radio frequency leakage Whether it is radiated by the antenna and then received by the base station, this method can realize the randomization of the interference without affecting the reception.

Embodiment three

According to another aspect of the embodiments of the present invention, a device for eliminating self-interference in a same-frequency full-duplex system is also provided, which is applied to a base station. As shown in FIG. 4 , the device 400 includes:

The first link module 401 is configured to establish a link with a terminal with registration authority;

The first negotiation module 403 is configured to negotiate with the terminal having the registration authority a dedicated uplink spreading code and a dedicated downlink spreading code, wherein the dedicated downlink spreading code is different from the dedicated uplink spreading code;

The first communication module 405 is configured to use the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the terminal with registration authority.

Optionally, as shown in FIG. 5, the first link module 401 includes:

The broadcast unit 4011 is used to broadcast the system information of the serving cell where the base station is located, the system information including the frequency, bandwidth, uplink and downlink time slot ratio used by the serving cell, and the public uplink used by the terminal with registration authority Spreading code and downlink spreading code;

Linking unit 4012, for judging whether the frequency band, bandwidth, and uplink-downlink time slot ratio used by a terminal are the same as the frequency, bandwidth, and uplink-downlink time slot ratio used by the serving cell, and if they are the same, obtain a terminal with registration authority , establishing a link with the terminal with registration authority, and receiving a registration request message sent by the terminal with registration authority according to the common uplink spreading code and downlink spreading code, wherein the registration request message includes the The uplink spreading code and downlink spreading code used by the terminal with the registration authority are described above.

Optionally, the first negotiation module 403 is specifically configured to:

According to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal with registration authority, negotiate with the terminal with registration authority to obtain a dedicated uplink Spreading code and dedicated downlink spreading code.

Optionally, as shown in FIG. 6, the first communication module 405 includes:

The downlink spreading unit 4051 is configured to use the dedicated downlink spreading code to spread the downlink signal, obtain the spread downlink signal, and send it to the terminal with registration authority;

The first receiving unit 4052 is configured to receive the self-interference signal generated during the process of sending the spread downlink signal, and the uplink signal spread by the terminal with registration authority using the dedicated uplink spreading code Signal;

The first despreading unit 4053 is configured to despread the self-interference signal and the spread uplink signal by using the dedicated uplink spreading code, and select the uplink signal from received signals.

Optionally, the downlink spreading unit 4051 is specifically configured to: multiply or add the downlink signal to the dedicated downlink spreading code to obtain a spread downlink signal.

Optionally, the first despreading unit 4053 is specifically configured to:

The self-interference signal and the uplink signal after spectrum spreading are respectively multiplied or added to the dedicated uplink spreading code.

Embodiment Four

According to another aspect of the embodiments of the present invention, a device for eliminating self-interference in a same-frequency full-duplex system is also provided, which is applied to a terminal. As shown in FIG. 7 , the device 700 includes:

The second linking module 701 is configured to establish a link with a base station that allows the terminal to register;

The second negotiation module 703 is configured to negotiate a dedicated uplink spreading code and a dedicated downlink spreading code with the base station that allows the terminal to register, wherein the dedicated uplink spreading code is different from the dedicated downlink spreading code ;

The second communication module 705 is configured to use the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the base station that allows the terminal to register.

Optionally, as shown in FIG. 8, the second link module 701 includes:

The acquiring unit 7011 is configured to acquire the system information broadcast by a base station of the serving cell where the base station is located, the system information including the frequency, bandwidth, uplink and downlink time slot ratio used by the serving cell, and the public uplink used by the access terminal Spreading code and downlink spreading code;

The second linking unit 7012 is used to determine whether the frequency band, bandwidth, and uplink-downlink time slot ratio used by the terminal are the same as the frequency, bandwidth, and uplink-downlink time slot ratio used by the serving cell. If the terminal is registered, establish a link with the base station that allows the terminal to register, and send a registration request message to the base station that allows the terminal to register according to the common uplink spreading code and downlink spreading code, wherein the The registration request message includes the uplink spreading code and downlink spreading code used by the terminal.

Optionally, the second negotiation module 703 is specifically configured to:

Negotiate with the base station that allows the terminal to register according to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal, to obtain a dedicated uplink spreading code code and dedicated downlink spreading code.

Optionally, as shown in FIG. 9, the second communication module 705 includes:

The uplink spreading unit 7051 is configured to use the dedicated uplink spreading code to spread the uplink signal, obtain the spread uplink signal, and send it to the base station that allows the terminal to register;

The second receiving unit 7052 is configured to receive the self-interference signal generated during the process of sending the spread uplink signal, and the base station that allows the terminal to register uses the dedicated downlink spread code to perform spread spectrum downlink signal;

The second despreading unit 7053 is configured to despread the self-interference signal and the spread downlink signal by using the dedicated downlink spreading code, and select the downlink signal from received signals.

Optionally, the uplink spreading unit 7051 is specifically configured to:

The uplink signal is multiplied or added to the dedicated uplink spreading code to obtain a spread uplink signal.

Optionally, the second despreading unit 7053 is specifically configured to:

The self-interference signal and the downlink signal after spreading are respectively multiplied or added to the dedicated downlink spreading code.

Certainly, in the specific implementation process, in order to enable the terminal equipment to eliminate the self-interference generated during the transmission process by using the method for eliminating self-interference of the same-frequency full-duplex system in the embodiment of the present invention, corresponding improvements can be made to the terminal equipment.

For example, as shown in Figure 13, for a terminal device with a single antenna, an analog-to-digital converter, a frequency spreader, a frequency converter, a pseudo-random sequence generator, and a circulator can be added inside the device, and the baseband integrated circuit ( BBIC) generates a baseband signal, which is up-converted and modulated by a radio frequency integrated circuit (RFIC) into a radio frequency signal that is conducive to channel transmission, and then amplified by an amplifier (PA) and filtered by a filter, then analog-to-digital conversion is performed to obtain a digital signal, and then the digital signal The signal is spread with a special spread code M1, and the spread signal is transmitted through the antenna. The antenna receives the downlink signal sent by the base station (the signal has been spread with the M2 spreading code on the base station side), and after despreading with the dedicated downlink spreading code M2, it is filtered by a filter, and then down-converted into a baseband signal by RFIC , BFIC demodulation for baseband processing to obtain the corresponding useful information.

As shown in Figure 14, for a dual-antenna terminal device, it is necessary to add an analog-to-digital converter, a frequency spreader, a frequency converter, and a pseudo-random sequence generator inside the device, and its principle of transmitting uplink signals and receiving downlink signals It is the same as that of the single-antenna terminal equipment, and will not be repeated here.

What has been described above is a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications can also be made without departing from the principles described in the present invention. within the scope of protection of the invention.

Claims (24)

1. A method for eliminating co-frequency full-duplex system self-interference, applied to the base station side, is characterized in that the method comprises: Establish a link with a terminal with registration authority; Negotiating with the terminal with registration authority a dedicated uplink spreading code and a dedicated downlink spreading code, wherein the dedicated downlink spreading code is different from the dedicated uplink spreading code; Using the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the terminal with registration authority. 2. The method according to claim 1, wherein establishing a link with a terminal with registration authority specifically comprises: Broadcast the system information of the serving cell where the base station is located, the system information includes the frequency, bandwidth, uplink and downlink time slot ratio used by the serving cell, and the public uplink spreading code and downlink spreading code used to access the terminal with registration authority. frequency code; Judging whether the frequency, bandwidth, and uplink and downlink time slot ratio used by a terminal are the same as the frequency band, bandwidth, and uplink and downlink time slot ratio used by the serving cell; A terminal with authorization establishes a link, and receives a registration request message sent by the terminal with registration authorization according to the public uplink spreading code and downlink spreading code, wherein the registration request message includes the registration request message of the terminal with registration authorization The uplink spreading code and downlink spreading code used. 3. The method according to claim 2, characterized in that, negotiating a dedicated uplink spreading code and a dedicated downlink spreading code with the terminal having registration authority, specifically: According to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal with registration authority, negotiate with the terminal with registration authority to obtain a dedicated uplink Spreading code and dedicated downlink spreading code. 4. The method according to claim 1, characterized in that, using the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the terminal having registration authority, specifically comprising: Spreading the downlink signal by using the dedicated downlink spreading code to obtain the spread downlink signal, and sending it to the terminal with registration authority; receiving the self-interference signal generated during the process of sending the spread downlink signal, and the uplink signal spread by the terminal with registration authority using the dedicated uplink spread code; Despreading the self-interference signal and the spread uplink signal by using the dedicated uplink spreading code, and selecting the uplink signal from received signals. 5. The method according to claim 4, wherein the downlink signal is spread by using the dedicated downlink spreading code, specifically: The downlink signal is multiplied or added to the dedicated downlink spreading code to obtain the downlink signal after spreading. 6. The method according to claim 4, characterized in that, using the dedicated uplink spreading code to despread the self-interference signal and the uplink signal after the spreading is specifically: The self-interference signal and the uplink signal after spectrum spreading are respectively multiplied or added to the dedicated uplink spreading code. 7. A method for eliminating self-interference in the same-frequency full-duplex system, applied to the terminal side, is characterized in that the method includes: establishing a link with a base station allowing said terminal to register; Negotiating a dedicated uplink spreading code and a dedicated downlink spreading code with the base station that allows the terminal to register, wherein the dedicated uplink spreading code is different from the dedicated downlink spreading code; performing same-frequency full-duplex communication with the base station allowing the terminal to register by using the dedicated uplink spreading code and the dedicated downlink spreading code. 8. The method according to claim 7, wherein establishing a link with a base station that allows the terminal to register specifically comprises: Acquiring the system information broadcast by a base station of the serving cell where the base station is located, the system information including the frequency, bandwidth, uplink and downlink time slot ratio used by the serving cell, and the common uplink spreading code and downlink spreading code used by the access terminal. frequency code; Judging whether the frequency band, bandwidth, and uplink-downlink time slot ratio used by the serving cell are the same as the frequency, bandwidth, and uplink-downlink time slot ratio used by the terminal, if they are the same, obtain a base station that allows the terminal to register, and The base station that allows the terminal to register establishes a link, and sends a registration request message to the base station that allows the terminal to register according to the common uplink spreading code and downlink spreading code, wherein the registration request message includes The uplink spreading code and downlink spreading code used by the terminal. 9. The method according to claim 8, characterized in that, negotiating a dedicated uplink spreading code and a dedicated downlink spreading code with the base station that allows the terminal to register, specifically: Negotiate with the base station that allows the terminal to register according to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal, to obtain a dedicated uplink spreading code code and dedicated downlink spreading code. 10. The method according to claim 7, characterized in that, using the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the base station that allows the terminal to register, specifically include: Spreading the uplink signal by using the dedicated uplink spreading code to obtain the spread uplink signal, and sending it to the base station that allows the terminal to register; receiving the self-interference signal generated during the process of sending the spread uplink signal, and the downlink signal spread by the base station allowing the terminal to register by using the dedicated downlink spread code; Despreading the self-interference signal and the spread downlink signal by using the dedicated downlink spreading code, and selecting the downlink signal from received signals. 11. The method according to claim 10, characterized in that, using the dedicated uplink spreading code to spread the uplink signal, specifically: The uplink signal is multiplied or added to the dedicated uplink spreading code to obtain a spread uplink signal. 12. The method according to claim 10, characterized in that, using the dedicated downlink spreading code to despread the self-interference signal and the spread downlink signal, specifically: The self-interference signal and the downlink signal after spreading are respectively multiplied or added to the dedicated downlink spreading code. 13. A device for eliminating self-interference in a same-frequency full-duplex system, applied to a base station, characterized in that the device includes: A first link module, configured to establish a link with a terminal with registration authority; A first negotiating module, configured to negotiate with the terminal having registration authority a dedicated uplink spreading code and a dedicated downlink spreading code, wherein the dedicated downlink spreading code is different from the dedicated uplink spreading code; The first communication module is configured to use the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the terminal with registration authority. 14. The device according to claim 13, wherein the first link module comprises: The broadcast unit is used to broadcast the system information of the serving cell where the base station is located. The system information includes the frequency, bandwidth, uplink and downlink time slot ratio used by the serving cell, and the public uplink extension used to access the terminal with registration authority. frequency code and downlink spreading code; A linking unit, used to determine whether the frequency, bandwidth, and uplink-downlink time slot ratio used by a terminal are the same as the frequency band, bandwidth, and uplink-downlink time slot ratio used by the serving cell, and if they are the same, obtain a terminal with registration authority, Establishing a link with the terminal with registration authority, and receiving a registration request message sent by the terminal with registration authority according to the public uplink spreading code and downlink spreading code, wherein the registration request message includes the Uplink spreading code and downlink spreading code used by terminals with registration authority. 15. The device according to claim 14, wherein the first negotiation module is specifically configured to: According to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal with registration authority, negotiate with the terminal with registration authority to obtain a dedicated uplink Spreading code and dedicated downlink spreading code. 16. The device according to claim 13, wherein the first communication module comprises: A downlink spreading unit, configured to spread the downlink signal by using the dedicated downlink spreading code, obtain the spread downlink signal, and send it to the terminal with registration authority; The first receiving unit is configured to receive the self-interference signal generated during the process of sending the spread downlink signal, and the uplink signal spread by the terminal with registration authority using the dedicated uplink spreading code ; The first despreading unit is configured to despread the self-interference signal and the spread uplink signal by using the dedicated uplink spreading code, and select the uplink signal from received signals. 17. The device according to claim 16, wherein the downlink spreading unit is specifically configured to: multiply or add the downlink signal to the dedicated downlink spreading code to obtain a spread downlink signal . 18. The device according to claim 16, wherein the first despreading unit is specifically used for: The self-interference signal and the uplink signal after spectrum spreading are respectively multiplied or added to the dedicated uplink spreading code. 19. A device for eliminating self-interference in a same-frequency full-duplex system, applied to a terminal, characterized in that the device includes: A second link module, configured to establish a link with a base station that allows the terminal to register; The second negotiation module is configured to negotiate a dedicated uplink spreading code and a dedicated downlink spreading code with a base station that allows the terminal to register, wherein the dedicated uplink spreading code is different from the dedicated downlink spreading code; The second communication module is configured to use the dedicated uplink spreading code and the dedicated downlink spreading code to perform same-frequency full-duplex communication with the base station that allows the terminal to register. 20. The device of claim 19, wherein the second link module comprises: An acquisition unit, configured to acquire system information broadcast by a base station of the serving cell where the base station is located, where the system information includes the frequency, bandwidth, uplink and downlink time slot ratio used by the serving cell, and the public uplink extension used by the access terminal. frequency code and downlink spreading code; The second linking unit is used to determine whether the frequency band, bandwidth, and uplink-downlink time slot ratio used by the serving cell are the same as those used by the terminal, and if they are the same, obtain permission The base station where the terminal is registered, establishes a link with the base station that allows the terminal to register, and sends a registration request message to the base station that allows the terminal to register according to the common uplink spreading code and downlink spreading code, wherein, The registration request message includes an uplink spreading code and a downlink spreading code used by the terminal. 21. The device according to claim 20, wherein the second negotiation module is specifically configured to: Negotiate with the base station that allows the terminal to register according to the public uplink spreading code and downlink spreading code of the serving cell, and the uplink spreading code and downlink spreading code used by the terminal, to obtain a dedicated uplink spreading code code and dedicated downlink spreading code. 22. The device according to claim 19, wherein the second communication module comprises: An uplink spreading unit, configured to use the dedicated uplink spreading code to spread the uplink signal, obtain the spread uplink signal, and send it to the base station that allows the terminal to register; The second receiving unit is configured to receive the self-interference signal generated during the process of sending the spread uplink signal, and the self-interference signal after the base station that allows the terminal to register uses the dedicated downlink spread code to spread the spectrum downlink signal; The second despreading unit is configured to despread the self-interference signal and the spread downlink signal by using the dedicated downlink spreading code, and select the downlink signal from received signals. 23. The device according to claim 22, wherein the uplink spreading unit is specifically used for: The uplink signal is multiplied or added to the dedicated uplink spreading code to obtain a spread uplink signal. 24. The device according to claim 22, wherein the second despreading unit is specifically used for: The self-interference signal and the downlink signal after spreading are respectively multiplied or added to the dedicated downlink spreading code.