WO2016070384A1

WO2016070384A1 - Self-interference elimination device and method

Info

Publication number: WO2016070384A1
Application number: PCT/CN2014/090486
Authority: WO
Inventors: 蔡毓; 梁栋
Original assignee: 华为技术有限公司
Priority date: 2014-11-06
Filing date: 2014-11-06
Publication date: 2016-05-12

Abstract

Disclosed in the embodiment are a self-interference elimination device and method, the method comprising: eliminating self-interference with respect to a low-frequency signal after converting a received radio-frequency signal to a low-frequency signal. Compared to self-interference elimination of a radio-frequency signal in the prior art, it is simpler and more feasible to eliminate self-interference on the low-frequency band, i.e., only using a mixer circuit and a self-interference elimination circuit, without using a large device such as a circulator, facilitating integration into a chip, and thereby reducing the volume of the self-interference elimination device.

Description

Self-interference cancellation device and method

Technical field

The present application relates to the field of communications, and in particular, to a self-interference cancellation apparatus and method.

Background technique

A full-duplex device is a device that can simultaneously transmit and receive signals. In order to eliminate the interference of the transmitted signal on the received signal, time-division multiplexing or frequency division multiplexing is usually used to transmit or receive the signal. The way, because of the sacrifice of time or frequency resources, the communication efficiency is reduced.

Therefore, at present, transmitting and receiving signals using the same frequency band at the same time has become a development trend, which puts higher demands on self-interference cancellation. In the prior art, self-interference cancellation is performed by using a circuit with a circulator, and the volume of the circulator is too large to be integrated into the chip, resulting in an excessive volume of the self-interference cancellation device.

Summary of the invention

The present application provides a self-interference cancellation device and method, and aims to solve the problem of excessive volume of the self-interference cancellation device caused by the inability of the self-interference circuit to be integrated into the chip.

In order to achieve the above object, the present application provides the following technical solutions:

A first aspect of the present application provides a self-interference cancellation apparatus, including:

a mixing circuit for converting the received RF signal into a low frequency signal;

The self-interference cancellation circuit is configured to perform self-interference cancellation on the low frequency signal output by the mixing circuit.

In the first implementation manner of the first aspect of the application, the mixing circuit specifically includes:

a first mixer for converting the received radio frequency signal into a low frequency signal;

a first amplifier for amplifying the low frequency signal and outputting the low frequency signal.

In a second implementation of the first aspect of the present application, the first mixer comprises an anti-blocking mixer.

In a third implementation manner of the first aspect of the present application, the self-interference cancellation circuit has Body includes:

a second mixer for converting a high frequency reference signal into a low frequency reference signal, the high frequency reference signal being generated according to a signal transmitted by a transmitting end of the full duplex device, and a receiving end of the full duplex device Receiving the radio frequency signal;

a second amplifier for amplifying the low frequency reference signal;

The self-interference canceller is configured to cancel the self-interference signal in the low frequency signal output by the mixing circuit by using the amplified low frequency reference signal.

In a fourth implementation manner of the first aspect of the application, the second mixer includes:

Anti-blocking mixer, or multi-phase mixer.

In a fifth implementation manner of the first aspect of the present application, the self-interference cancellation circuit includes:

a self-interference canceller, configured to cancel a self-interference signal in the low-frequency signal output by the mixing circuit by using a low-frequency reference signal, where the reference signal is generated according to the first signal, and the first signal is a full-duplex device The transmitted signal is a low frequency signal prior to frequency conversion, and the receiving end of the full duplex device is configured to receive the radio frequency signal.

In a sixth implementation manner of the first aspect of the application, the mixing circuit specifically includes:

a first mixing unit including M first mixers, each of the first mixers for converting the radio frequency signal into a low frequency signal, the M being an integer greater than one;

a first amplifying unit, comprising: M first amplifiers corresponding to the M first mixers, wherein the first amplifier is configured to amplify a low frequency signal outputted by the mixer corresponding thereto;

The weight unit is configured to obtain a low frequency signal by multiplying the M low frequency signals output by the M first amplifiers by a preset weight and adding them respectively.

In the seventh implementation manner of the first aspect of the present application, the self-interference cancellation circuit specifically includes:

a second mixing unit, comprising N second mixers, each of the second mixers for converting the high frequency reference signal into a low frequency reference signal, the N being an integer greater than one;

a second amplifying unit, comprising: N second amplifiers corresponding to the N second mixers, wherein the second amplifier is configured to amplify a low frequency reference signal outputted by the mixer corresponding thereto;

And a self-interference canceller for canceling the self-interference signal in the low frequency signal output by the mixing circuit by using the low frequency reference signal output by the N second amplifiers.

In an eighth implementation manner of the first aspect of the present application, the self-interference cancellation circuit further includes:

And a phase shifting circuit, configured to receive the low frequency reference signal output by the second mixer, and phase shift the low frequency reference signal to output to the second amplifier.

In a ninth implementation manner of the first aspect of the application, the method further includes:

A secondary frequency down circuit for converting a low frequency signal subjected to self-interference cancellation into a baseband signal.

A second aspect of the present application provides a full duplex device comprising the self-interference cancellation device described above.

A third aspect of the present application provides a self-interference cancellation method, including:

Converting the received RF signal into a low frequency signal;

Self-interference cancellation is performed on the low frequency signal.

In the first implementation manner of the third aspect of the present application, before the self-interference cancellation of the low frequency signal, the method further includes:

Amplifying the low frequency signal;

The self-interference cancellation of the low frequency signal includes:

Self-interference cancellation of the amplified self-interference signal.

In a second implementation manner of the third aspect of the present application, the performing self-interference cancellation on the low frequency signal includes:

Converting the high frequency reference signal into a low frequency reference signal, the high frequency reference signal being generated according to a signal transmitted by a transmitting end of the full duplex device, and the receiving end of the full duplex device is configured to receive the radio frequency signal;

Amplifying the low frequency reference signal;

The self-interference signal in the low frequency signal is cancelled by the amplified low frequency reference signal.

In a third implementation manner of the third aspect of the present application, the performing self-interference cancellation on the low frequency signal includes:

Determining the self-interference signal in the low frequency signal by using a low frequency reference signal, the reference signal being generated according to the first signal, wherein the first signal is a low frequency signal of the radio frequency signal before the frequency conversion, and the radio frequency signal is the full double The signal transmitted by the transmitting end of the equipment.

In a fourth implementation manner of the third aspect of the present application, the receiving the full duplex device The conversion of the RF signal to a low frequency signal includes:

Converting the radio frequency signal into M low frequency signals through M first mixing branches, where M is an integer greater than one;

Amplifying the M low frequency signals separately;

The low frequency signal is obtained by multiplying the amplified low frequency signals by the preset weights and adding them.

In a fifth implementation manner of the third aspect of the present application, the performing self-interference cancellation on the low frequency signal includes:

Converting the high frequency reference signal into N low frequency reference signals through N second mixing branches, wherein N is an integer greater than one;

Amplifying the N low frequency reference signals separately;

The N-channel amplified low-frequency reference signal is used to cancel the self-interference signal in the low-frequency signal.

In a sixth implementation manner of the third aspect of the present application, before the amplifying the low frequency reference signal, the method further includes:

Phase shifting the low frequency reference signal;

The amplifying the low frequency reference signal comprises:

The phase-shifted low frequency reference signal is amplified.

In the seventh implementation manner of the third aspect of the present application, after the self-interference cancellation of the low frequency signal, the method further includes:

The low frequency signal subjected to self-interference cancellation is converted into a baseband signal.

The self-interference cancellation device and method disclosed in the present application converts the received radio frequency signal into a low frequency signal, and performs self-interference cancellation on the low frequency signal, which is lower than the self-interference cancellation method of the radio frequency signal in the prior art. Self-interference cancellation in the frequency band is simpler and easier, that is, only the mixing circuit and the self-interference cancellation circuit can be used, and it is not necessary to use an excessively large device such as a circulator, so that it is easy to integrate into the chip, thereby reducing Self-interference eliminates the volume of the device.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art description will be briefly described below, obviously, The drawings in the following description are only some of the embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

1 is a schematic diagram of a full duplex device transmitting and receiving signals;

2 is a schematic structural diagram of a self-interference cancellation device according to an embodiment of the present invention;

3 is a schematic structural diagram of still another self-interference cancellation device according to an embodiment of the present invention;

4 is a schematic structural diagram of a self-interference cancellation device according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a self-interference cancellation circuit in a self-interference cancellation device according to an embodiment of the present invention; FIG.

FIG. 6 is a flowchart of a self-interference cancellation method according to an embodiment of the present invention;

FIG. 7 is a flowchart of still another method for self-interference cancellation according to an embodiment of the present invention;

FIG. 8 is a flowchart of still another method for self-interference cancellation according to an embodiment of the present invention.

detailed description

The self-interference cancellation apparatus and method disclosed in the embodiments of the present application can be applied to a full-duplex device for eliminating interference of a transmitted signal of a full-duplex device to a useful signal received by the same.

As shown in FIG. 1, the full-duplex device has a transmitting end and a receiving end, the transmitting end is configured to transmit a signal, and the receiving end is configured to receive a signal, wherein the full-duplex device transmits a signal S0 when transmitting the signal S0. After passing through the channel H1, S1 is formed, and S1 can be received by the receiving end. It is assumed that when the signal S0 is transmitted, the receiving end is receiving the signal S2, and the signal finally received by the receiving end is S1+S2. For S2, S1 is the interference signal, and self-interference cancellation is to eliminate the signal S1 from the signal S1+S2.

The full-duplex device can work in a Global System for Mobile communication (GSM), Long Term Evolution (LTE), or Universal Mobile Telecommunications System (UMTS) system. The application examples are not limited.

The technical solutions in the embodiments of the present application are clearly and completely described in the following with reference to the drawings in the embodiments of the present application. It is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts are protected by the present application. range.

A self-interference cancellation device disclosed in the embodiment of the present application, as shown in FIG. 2, includes:

Mixing circuit 201 and self-interference cancellation circuit 202.

The mixing circuit 201 is configured to convert a radio frequency signal (for example, S1+S2 in FIG. 1) received by the full duplex device into a low frequency signal; and the self interference cancellation circuit 202 is configured to output the frequency mixing circuit. The low frequency signal is self-interference cancelled.

The self-interference cancellation device described in this embodiment can be applied to a full-duplex device. After receiving the radio frequency signal, the radio frequency signal is converted into a low-frequency signal, and the low-frequency signal is self-interference-cancelled.

In the prior art, self-interference cancellation is usually performed before mixing, that is, self-interference cancellation is directly performed on the radio frequency signal.

It can be seen that, compared with the prior art, the device described in this embodiment has a great change in the idea of self-interference cancellation, because the processing of the low-frequency signal is easier to implement in hardware than the high-frequency signal, so The device described in this embodiment is easier to implement industrially. Moreover, as can be seen from FIG. 2, in this embodiment, only the mixing receiving circuit and the self-interference eliminating circuit are needed, and the circulator is not needed, so that it can be integrated in the chip, which is advantageous for reducing the volume of the full-duplex device. .

Another self-interference cancellation device disclosed in the embodiment of the present application, as shown in FIG. 3, includes: a first mixer 301, a first amplifier 302, a second mixer 303, a second amplifier 304, and a self-interference canceller. 305.

The first mixer 301 is configured to convert the radio frequency signal received by the full duplex device into a low frequency signal. In this embodiment, the first mixer 301 may be an anti-blocking mixer, and the purpose is to suppress the strong self-interference signal. The resulting blocking effect. In Figure 3, the input signal at one input of the first mixer is a radio frequency signal and the input signal at the other input is a local oscillator signal F- _LO-1 .

The first amplifier 302 is configured to amplify the low frequency signal and output the output. In this embodiment, the first amplifier may be a transimpedance amplifier.

The second mixer 303 is for converting the high frequency reference signal into a low frequency reference signal and outputting it.

The high frequency reference signal is generally generated according to the transmission signal of the full duplex device. For example, in FIG. 1, the transmission signal is S0, and the high frequency reference signal may be S1. High frequency reference signal can pass Obtained in the following ways: coupling with air ports or coupling with balun circuits. Likewise, the second mixer can also be an anti-blocking mixer.

The second amplifier 304 is configured to amplify the low frequency reference signal and output the second amplifier, and the second amplifier may also be a transimpedance amplifier.

The self-interference canceller 305 is configured to cancel the self-interference signal in the low frequency signal output by the first amplifier by using the low frequency reference signal.

In this embodiment, the self-interference canceller may be an analog device such as an operational amplifier, an adder, or the like for canceling the self-interference signal by adding the low frequency reference signal to the low frequency signal output by the first amplifier. In Fig. 3, an adder is taken as an example.

In addition, as shown in FIG. 3, in the present embodiment, after the self-interference canceller completes the self-interference cancellation, the self-interference-removing signal can be sent to the digital signal processing portion for analysis.

The self-interference cancellation device described in the embodiment converts the radio frequency signal and the high-frequency interference signal into a low-frequency signal through a mixer, thereby realizing self-interference cancellation in a low frequency band, thereby facilitating hardware integration, thereby reducing the full double The size and cost of the equipment.

In addition, in addition to the above self-interference cancellation circuit, in the embodiment of the present application, the self-interference cancellation circuit may also be: the self-interference canceller, that is, the self-interference cancellation circuit does not include the mixing circuit, but only Self-interference canceller. The self-interference canceller is configured to eliminate a self-interference signal in the low-frequency signal output by the mixing circuit by using a low-frequency reference signal, and different from the above embodiment, the low-frequency reference signal is according to the self-interference cancellation device. The transmitted signal is generated by the low frequency signal before the frequency conversion (for example, the baseband signal of the transmitted signal), that is, the reference signal for self-interference cancellation, no longer uses the high frequency signal, but directly uses the baseband signal of the transmitted signal before the frequency conversion. In this case, the volume of the device can be further reduced.

Another self-interference cancellation device disclosed in the embodiment of the present application, as shown in FIG. 4, includes:

The first mixer 401, the first amplifier 402, the second mixing unit 403, the second amplifying unit 404, and the self-interference canceller 405.

The second mixing unit 403 is configured to convert the high frequency reference signal F - _REF into a low frequency reference signal, including N second mixers Mixer - ₀ ... Mixer - n, the second mixer Mixer - ₀ ... Mixer-n is used to convert the high frequency reference signal into a low frequency reference signal, respectively.

Wherein N is an integer greater than 1. The second mixer can be a multiphase mixer.

The second amplifying unit 404 includes N second amplifiers TIA1 . . . TIAn corresponding to the N second mixers, and the second amplifier is configured to amplify the low frequency reference signal of the mixer output corresponding thereto and F _-L1 ...... F _-Ln output reference low-frequency amplified signal to the interference canceller 406.

In addition to the above structure, in the present embodiment, the functions of the first mixer 401 and the first amplifier 402 can be referred to the above embodiment.

In this embodiment, by using the N second mixers, the converted low-frequency reference signal, that is, the reconstructed interference signal, is closer to the multipath and multi-time formed by the radio frequency signal transmitted by the full-duplex device in the channel. The interference signal is delayed, so that the self-interference signal can be eliminated more accurately. Moreover, it can be used to replace the concept of delay line analog multipath by using a phase shifter or a delay line for an early full-duplex receiver.

Further, the mixing receiving circuit may include a plurality of mixers and amplifiers, that is, the mixing receiving circuit specifically includes:

a first mixing unit for including M first mixers, each of the first mixers for converting the radio frequency signal into a low frequency signal, the M being an integer greater than 1, wherein A mixer can be a multiphase mixer

And a first amplifying unit, comprising: M first amplifiers corresponding to the M first mixers, wherein the first amplifier is used to amplify a low frequency signal outputted by the mixer corresponding thereto.

Compared with the above-mentioned mixing circuit composed of a single mixer and a single-phase mixer, the multi-channel multi-phase mixing receiving circuit has the advantages that it can be better integrated with the digital circuit of the back end, and the multi-phase mixing is controlled by the digital circuit. The gain of the frequency converter is beneficial for integration with the back-end digital processing chip.

Further, optionally, in the apparatus shown in FIG. 3 or FIG. 4, the self-interference cancellation circuit may further include a phase shifting circuit, such as an RC phase shifting circuit.

As shown in FIG. 5, a phase shifting circuit is configured to receive a low frequency reference signal output by the second mixer, The low frequency reference signal is phase shifted and output to the second amplifier.

Adding a phase shifting circuit can realize the function of changing the signal delay to facilitate the function of the delay line.

Still further, optionally, it may also be extended based on the apparatus of FIG. 3 or FIG. 4: a secondary frequency conversion circuit is added to the apparatus shown in FIG. 3 or FIG. The secondary frequency conversion circuit may be a mixer or other frequency reduction circuits. The advantage of adding a second down-converting circuit is that the low frequency signal can be converted to a baseband signal for digital processing of the signal.

The embodiment of the present application further discloses a full-duplex device, which may include the self-interference cancellation device described in the foregoing embodiments.

The embodiment of the present application further discloses a self-interference cancellation method, as shown in FIG. 6, which includes the following steps:

S601: Convert the radio frequency signal received by the full duplex device into a low frequency signal;

S602: Perform self-interference cancellation on the low frequency signal.

The method described in this embodiment can also be applied in a full-duplex device. After receiving the radio frequency signal at the receiving end of the full-duplex, the radio frequency signal is converted into a low-frequency signal, and then the self-interference is cancelled by the low-frequency signal. Compared with the prior art method for self-interference cancellation of radio frequency signals, the method described in this embodiment is easier to implement because self-interference is eliminated in a low frequency band, and the requirements for the receiving end device of the full-duplex device are low. There is no need to use a circulator, thus making it easier for a full-duplex device to implement chip integration, thereby helping to reduce the size of a full-duplex device.

Another self-interference cancellation method disclosed in the embodiment of the present application, as shown in FIG. 7, includes the following steps:

S701: Convert the radio frequency signal received by the full duplex device into a low frequency signal;

S702: Amplify the low frequency signal;

S703: Convert the high frequency reference signal into a low frequency reference signal;

The high frequency reference signal is generated according to a signal transmitted by a transmitting end of the full duplex device.

S704: Amplify the low frequency reference signal;

S705: using the amplified low frequency reference signal to eliminate the self-interference signal in the amplified low frequency signal;

S706: Convert the low frequency signal subjected to self-interference cancellation into a baseband signal.

In this embodiment, in addition to the self-interference cancellation method described in S703 to S705, the specific process of self-interference cancellation may be: using a low-frequency reference signal to eliminate a self-interference signal in the low-frequency signal, the reference signal According to the first signal generation, the first signal is a low frequency signal of the radio frequency signal before the frequency conversion, and the radio frequency signal is a signal transmitted by the transmitting end of the full duplex device.

For the specific implementation device or device of the steps in this embodiment, refer to FIG. 3, for example, the radio frequency signal is converted into a low frequency signal by using a mixer, and details are not described herein. The method described in this embodiment can be implemented using an integrated chip circuit, thereby facilitating the reduction of hardware volume.

Another self-interference cancellation circuit disclosed in the embodiment of the present application, as shown in FIG. 8 , specifically includes:

S801: The radio signal received by the full duplex device is converted into the M low frequency signal by the M first mixing branches;

Wherein M is an integer greater than one.

S802: Amplify the M low frequency signals separately;

S803: multiplying the amplified low frequency signals by the preset weights and adding them to obtain a low frequency signal;

S804: Convert the high frequency reference signal into N low frequency reference signals through the N second mixing branches;

Wherein, N is an integer greater than 1, and N and M may be the same or different.

S805: phase shifting the N low frequency reference signals respectively;

S806: amplifying the low frequency reference signals after phase N phase shifting respectively;

S807: Eliminate the self-interference signal in the low frequency signal by using the N channel amplified low frequency reference signal.

The implementation circuit involved in the above steps can refer to the circuit shown in FIG. 4 and FIG. 5, and here is not Let me repeat.

In this embodiment, the N-channel second down-converting branch and the second amplifier can simulate a self-interference signal formed by the multi-path transmission of the signal transmitted by the full-duplex device, so that the self-interference signal can be more accurately removed. The interference signal; the advantage of the N-channel frequency reduction of the radio frequency is that it can be better integrated with the digital circuit of the back end, and the gain of the multi-phase mixer is controlled by the digital circuit, which is beneficial to integration with the back-end digital processing chip; The addition of phase shifting enables the function of changing the signal delay to facilitate the function of the delay line.

The functions described in the method of the present embodiment can be stored in a computing device readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on such understanding, a portion of the embodiments of the present invention that contributes to the prior art or a portion of the technical solution may be embodied in the form of a software product stored in a storage medium, including a plurality of instructions for causing a The computing device (which may be a personal computer, server, mobile computing device, or network device, etc.) performs all or part of the steps of the methods described in various embodiments of the present invention. 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. .

The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on differences from other embodiments, and the same or similar parts of the respective embodiments may be referred to each other.

The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but the scope of the invention is to be accorded

Claims

A self-interference cancellation device, comprising:

a mixing circuit for converting the received RF signal into a low frequency signal;

The self-interference cancellation circuit is configured to perform self-interference cancellation on the low frequency signal output by the mixing circuit.
The self-interference cancellation device according to claim 1, wherein the mixing circuit specifically includes:

a first mixer for converting the received radio frequency signal into a low frequency signal;

a first amplifier for amplifying the low frequency signal and outputting the low frequency signal.
The self-interference cancellation device of claim 2 wherein said first mixer comprises an anti-blocking mixer.
The self-interference cancellation device according to any one of claims 1 to 3, wherein the self-interference cancellation circuit specifically includes:

a second mixer for converting a high frequency reference signal into a low frequency reference signal, the high frequency reference signal being generated according to a signal transmitted by a transmitting end of the full duplex device, and a receiving end of the full duplex device Receiving the radio frequency signal;

a second amplifier for amplifying the low frequency reference signal;

The self-interference canceller is configured to cancel the self-interference signal in the low frequency signal output by the mixing circuit by using the amplified low frequency reference signal.
The self-interference cancellation device according to claim 4, wherein the second mixer comprises:

Anti-blocking mixer, or multi-phase mixer.
The self-interference cancellation device according to any one of claims 1 to 3, wherein the self-interference cancellation circuit comprises:

a self-interference canceller, configured to cancel a self-interference signal in the low-frequency signal output by the mixing circuit by using a low-frequency reference signal, where the reference signal is generated according to the first signal, and the first signal is a full-duplex device The transmitted signal is a low frequency signal prior to frequency conversion, and the receiving end of the full duplex device is configured to receive the radio frequency signal.
The self-interference cancellation device according to claim 1, wherein said mixing electric power The road specifically includes:

a first mixing unit including M first mixers, each of the first mixers for converting the radio frequency signal into a low frequency signal, the M being an integer greater than one;

a first amplifying unit, comprising: M first amplifiers corresponding to the M first mixers, wherein the first amplifier is configured to amplify a low frequency signal outputted by the mixer corresponding thereto;

The weight unit is configured to obtain a low frequency signal by multiplying the M low frequency signals output by the M first amplifiers by a preset weight and adding them respectively.
The self-interference cancellation device according to claim 1 or 7, wherein the self-interference cancellation circuit specifically includes:

a second mixing unit, comprising N second mixers, each of the second mixers for converting the high frequency reference signal into a low frequency reference signal, the N being an integer greater than one;

a second amplifying unit, comprising: N second amplifiers corresponding to the N second mixers, wherein the second amplifier is configured to amplify a low frequency reference signal outputted by the mixer corresponding thereto;

And a self-interference canceller for canceling the self-interference signal in the low frequency signal output by the mixing circuit by using the low frequency reference signal output by the N second amplifiers.
The self-interference cancellation device according to claim 4, 5 or 8, wherein the self-interference cancellation circuit further comprises:

And a phase shifting circuit, configured to receive the low frequency reference signal output by the second mixer, and phase shift the low frequency reference signal to output to the second amplifier.
The self-interference cancellation device according to any one of claims 1 to 9, further comprising:

A secondary frequency down circuit for converting a low frequency signal subjected to self-interference cancellation into a baseband signal.
A full-duplex device comprising the self-interference cancellation device according to any one of claims 1 to 10.
A self-interference cancellation method, comprising:

Converting the received RF signal into a low frequency signal;

Self-interference cancellation is performed on the low frequency signal.
The method according to claim 12, further comprising: before said self-interference cancellation of said low frequency signal, further comprising:

Amplifying the low frequency signal;

The self-interference cancellation of the low frequency signal includes:

Self-interference cancellation of the amplified self-interference signal.
The method according to claim 12 or 13, wherein said self-interference cancellation of said low frequency signal comprises:

Converting the high frequency reference signal into a low frequency reference signal, the high frequency reference signal being generated according to a signal transmitted by a transmitting end of the full duplex device, and the receiving end of the full duplex device is configured to receive the radio frequency signal;

Amplifying the low frequency reference signal;

The self-interference signal in the low frequency signal is cancelled by the amplified low frequency reference signal.
The method according to claim 12 or 13, wherein said self-interference cancellation of said low frequency signal comprises:

Determining the self-interference signal in the low frequency signal by using a low frequency reference signal, the reference signal being generated according to the first signal, wherein the first signal is a low frequency signal of the radio frequency signal before the frequency conversion, and the radio frequency signal is the full double The signal transmitted by the transmitting end of the equipment.
The method according to claim 12, wherein the converting the radio frequency signal received by the full duplex device into the low frequency signal comprises:

Converting the radio frequency signal into M low frequency signals through M first mixing branches, where M is an integer greater than one;

Amplifying the M low frequency signals separately;

The low frequency signal is obtained by multiplying the amplified low frequency signals by the preset weights and adding them.
The method according to claim 12 or 16, wherein the self-interference cancellation of the low frequency signal comprises:

Converting the high frequency reference signal into N low frequency reference signals through N second mixing branches, wherein N is an integer greater than one;

Amplifying the N low frequency reference signals separately;

The N-channel amplified low-frequency reference signal is used to cancel the self-interference signal in the low-frequency signal.
A method according to claim 14, 15 or 17, wherein said Before the low frequency reference signal is amplified, the method further includes:

Phase shifting the low frequency reference signal;

The amplifying the low frequency reference signal comprises:

The phase-shifted low frequency reference signal is amplified.
The method according to any one of claims 12 to 18, further comprising: after the self-interference cancellation of the low frequency signal,

The low frequency signal subjected to self-interference cancellation is converted into a baseband signal.