Same-frequency interference rapid elimination device suitable for time-varying environment

Abstract

The invention provides a same-frequency interference rapid elimination device suitable for a time-varying environment, and belongs to the technical field of wireless communication. The device comprises an elimination unit and a parameter pre-calculation unit. And the parameter pre-calculation unit comprises a signal pre-conditioning unit and a feedback control unit. The signal pre-conditioning unit is used for pre-calculation of offset signal parameters, and the feedback control unit sends the offset signal parameters obtained through pre-calculation to the elimination unit. And a signal conditioning unit in the elimination unit receives the offset signal parameter from the parameter pre-calculation unit and is used for generating a same-frequency interference offset signal. And the same-frequency interference signal and an offset signal output by the elimination unit are added and offset, and finally a required useful signal is obtained. According to the device, as long as the parameter pre-calculation time is shorter than the adjustment interval, the parameter pre-calculation unit completes offset signal parameter calculation in advance at each adjustment interval and updates the offset signal parameters to the offset unit to complete offset, same-frequency full-duplex application interruption caused by a traditional method can be avoided.

Description

Technical Field

[0001] The invention relates to a device for quickly eliminating same-frequency interference suitable for a time-varying environment, and belongs to the technical field of wireless communication. Background Art

[0002] When radio equipment transmits signals, it will cause strong co-channel self-interference to its own receiver, making it impossible for the radio equipment to receive co-channel signals from other devices at the same time, limiting the application of radio equipment. Co-channel interference elimination technology overcomes this limitation. On radio equipment that uses co-channel interference elimination technology, simultaneous co-channel full-duplex communication can be achieved, thereby improving spectrum efficiency. It can also be used for spectrum detection to avoid spectrum detection blind spots caused by co-channel interference.

[0003] At present, there are many methods for eliminating co-channel interference, which are mainly divided into two categories: passive elimination and active elimination. Among them, passive elimination improves the isolation between transmitter and receiver through special structural design and other means. The advantages are relatively simple structure and low cost, and the disadvantages are that the elimination performance is very limited and far from meeting the needs. The commonly used method for active elimination is to reconstruct an interference cancellation signal with equal amplitude and opposite phase to the co-channel interference signal, and add it to the received signal mixed with the co-channel interference signal at the front end of the receiver, thereby realizing the active elimination of the co-channel interference signal. Compared with passive elimination technology, the disadvantage of active elimination is that the technology is more complex and costly, but the elimination performance that can be achieved is usually stronger, and it is an inevitable technical approach for simultaneous co-channel transmission and reception applications.

[0004] Since the real environment is time-varying, the active co-channel interference elimination circuit needs to dynamically adjust the elimination parameters to adapt to environmental changes. In traditional co-channel interference elimination devices, the signal conditioning unit is used to generate the cancellation signal, which will cause the cancellation performance to deteriorate or even fail during the parameter adjustment period, causing adverse effects such as performance degradation and interruption on simultaneous co-channel applications. Especially in fast time-varying scenarios, frequent adjustment of the cancellation parameters will cause the failure of such applications.

[0005] Therefore, the speed of eliminating co-channel interference is one of the important factors that currently restrict the application of co-channel interference elimination technology. Summary of the invention

[0006] The purpose of the present invention is to solve the technical problem of the co-channel interference elimination speed in an active co-channel interference elimination circuit, and creatively proposes a co-channel interference fast elimination device suitable for a time-varying environment.

[0007] The device of the present invention belongs to an active co-channel interference elimination device, and its core includes an elimination unit and a parameter pre-calculation unit. Compared with the traditional co-channel interference elimination device, the innovation of the present invention is that a parameter pre-calculation unit is added. The parameter pre-calculation unit includes a signal pre-conditioning unit and a feedback control unit. The signal pre-conditioning unit is used to pre-calculate the cancellation signal parameters, and the feedback control unit sends the pre-calculated cancellation signal parameters to the elimination unit. The signal conditioning unit in the elimination unit receives the cancellation signal parameters from the parameter pre-calculation unit, and is used to generate a co-channel interference cancellation signal. The signal from the receiving antenna contains a useful signal and a co-channel interference signal, wherein the co-channel interference signal is added and canceled with the cancellation signal output from the elimination unit, and finally the desired useful signal is obtained.

[0008] Beneficial Effects

[0009] Compared with the prior art, the present invention has the following advantages:

[0010] In the application scenarios of wireless communication, the external environment is often time-varying. Traditional co-channel interference elimination devices need to readjust parameters at regular intervals to adapt to changes in the external environment. During the parameter adjustment period, the self-interference elimination performance will decrease, resulting in communication interruption. The device of the present invention uses a parameter pre-calculation unit independent of the receiving link to pre-calculate the cancellation signal parameters required to generate the cancellation signal. It only needs to be less than the adjustment interval for the parameter pre-calculation time to complete the cancellation signal parameter calculation in advance at each adjustment interval, and update the cancellation signal parameters to the cancellation unit to complete the cancellation, thereby avoiding the interruption of co-channel full-duplex applications caused by traditional methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic diagram of the device of the present invention;

[0012] Among them: 100-parameter pre-calculation unit, 101-signal pre-conditioning unit, 102-second combiner, 103-feedback control unit, 200-elimination unit, 201-signal conditioning unit, 202-first combiner, 203-coupler, 301-three-power divider, 302-transmitting antenna, 303-receiving antenna, 304-two-power divider. DETAILED DESCRIPTION

[0013] The invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0014] Example

[0015] like Figure 1 As shown, a device for quickly eliminating co-channel interference suitable for a time-varying environment includes a parameter pre-calculation unit 100, an elimination unit 200, a three-power divider 301, a transmitting antenna 302, a receiving antenna 303, and a two-power divider 304.

[0016] The parameter pre-calculation unit 100 includes a signal pre-conditioning unit 101 , a second combiner 102 and a feedback control unit 103 .

[0017] The signal preconditioning unit 101 processes the signal from the three-power divider 301 and outputs a cancellation signal with equal amplitude and opposite phase to the co-channel interference signal. The cancellation signal is added to the output signal from the second power divider 304 in the second combiner 102 to obtain a signal after the co-channel interference is cancelled. The cancelled signal is sent to the feedback control unit 103, which monitors the signal power from the second combiner 102 and the cancellation unit 200, and performs feedback control on the signal preconditioning unit 101 in the parameter pre-calculation unit 100 and the signal conditioning unit 201 in the elimination unit 200 to achieve optimal co-channel interference elimination.

[0018] The cancellation unit 200 includes a signal conditioning unit 201, a first combiner 202 and a coupler 203. The signal conditioning unit 201 processes the signal from the three-power divider 301 and outputs a cancellation signal with the same amplitude and opposite phase as the co-channel interference signal. The cancellation signal is added to the signal output from the second power divider 304 in the first combiner 202 to obtain a signal after the co-channel interference is cancelled. The cancelled signal is sent to the coupler 203.

[0019] The three-way power divider 301 divides the transmission signal of the external transmitter into three signals with the same components, one of which is sent to the transmitting antenna 302 for transmission, one is sent to the parameter pre-calculation unit 100 for generating the elimination parameters required by the elimination unit 200, and one is sent to the elimination unit 200 for generating the cancellation signal.

[0020] The dual power divider 304 divides the mixed signal containing the useful signal and the co-channel interference signal from the receiving antenna 303 into two paths, and sends them to the elimination unit 200 and the parameter pre-calculation unit 100 respectively.

[0021] Among them, the output end of the signal pre-conditioning unit 101 is connected to the input end of the second combiner 102; the output end of the second combiner 102 is connected to the input end of the feedback control unit 103; the output end of the feedback control unit 103 is respectively connected to the input end of the signal pre-conditioning unit 101 and the input end of the signal conditioning unit 201.

[0022] The output end of the signal conditioning unit 201 is connected to the input end of the first combiner 202. The output end of the first combiner 202 is connected to the input end of the coupler 203. The output end of the coupler 203 is connected to an external receiver and the feedback control unit 103 in the parameter pre-calculation unit 100, respectively.

[0023] The input end of the three-power divider 301 is connected to an external transmitter. The output end of the three-power divider 301 is respectively connected to the transmitting antenna 302, the parameter pre-calculation unit 100 and the elimination unit 200. The input end of the two-power divider 304 is connected to the receiving antenna 303. The output end of the two-power divider 304 is respectively connected to the input end of the second combiner 102 and the first combiner 202.

[0024] Furthermore, the transmission signal X(t) output from the transmitter is divided into three signals x1(t), x2(t) and x3(t) with the same components by the three-way power divider 301. x1(t) is input to the transmitting antenna 302 for transmission. x2(t) is input to the parameter pre-calculation unit 100 for participating in the calculation of the cancellation signal parameters required to generate the cancellation signal. x3(t) is input to the elimination unit 200 for generating the cancellation signal;

[0025] After the signal r(t) received by the receiving antenna 303 passes through the two power dividers 304, two signals r1(t) and r2(t) with the same components are output. r1(t) is input to the parameter pre-calculation unit 100 to participate in the calculation of the cancellation signal parameters required to generate the cancellation signal. r2(t) is input to the elimination unit 200, and after the elimination unit 200 performs co-channel interference elimination, the interference-eliminated receiving signal y(t) is output.

[0026] The signal r(t) received by the receiving antenna 303 is output through the two-way power divider 304 as two signals r1(t) and r2(t) with the same components, as shown in the following formula:

[0027] r1(t)=r2(t)=ax(t-Δt)+u(t)

[0028] Wherein, ax(t-Δt) is the same-frequency interference signal; u(t) is the useful signal received by the receiving antenna 303;

[0029] x2(t) is input into the parameter pre-calculation unit 100, and the signal is conditioned in the signal pre-conditioning unit 101, and the pre-cancellation signal c1(t) is output. c1(t) is combined and added with r1(t) in the second combiner 102, and the added signal y'(t) is sent to the feedback control unit 103. The feedback control unit 103 performs feedback adjustment on the signal pre-conditioning unit 101, so that the signal component of c1(t) and the co-frequency interference signal ax(t-Δt) contained in r1(t) are equal in amplitude and opposite in phase: c1(t) = -ax(t-Δt), thereby achieving addition cancellation in the combiner 102:

[0030] y'(t)=c1(t)+r1(t)=-ax(t-Δt)+ax(t-Δt)+u(t)=u(t)

[0031] After the above process, the feedback control unit 103 in the parameter pre-calculation unit 100 obtains the cancellation signal parameters required to generate the cancellation signal, and the cancellation signal parameters are sent to the signal conditioning unit 201 in the elimination unit 200. The signal conditioning unit 201 performs signal conditioning on x3(t) and outputs the cancellation signal c2(t). The signal component of c2(t) is equal in amplitude and opposite in phase to the co-frequency interference signal ax(t-Δt) contained in r2(t):

[0032] c2(t)=-ax(t-Δt)

[0033] Therefore, the co-channel interference signal contained in r2(t) is added and cancelled with c2(t) in the first combiner 202, and the cancelled signal y(t) is outputted through the output end of the coupler 203:

[0034] y(t)=c2(t)+r2(t)=-ax(t-Δt)+ax(t-Δt)+u(t)=u(t)

[0035] The coupling output end of the coupler 203 is connected to the feedback control unit 103 for detecting the canceled signal and assisting the feedback control to achieve the best cancellation effect.

[0036] The specific description above further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device for quickly eliminating co-channel interference in a time-varying environment, characterized in that: It includes a parameter pre-calculation unit (100), an elimination unit (200), a three-power splitter (301), a transmitting antenna (302), a receiving antenna (303), and a two-power splitter (304); The parameter pre-calculation unit (100) comprises a signal pre-conditioning unit (101), a second combiner (102) and a feedback control unit (103); The signal preconditioning unit (101) processes the signal from the three-power divider (301) and outputs a cancellation signal with the same amplitude and opposite phase as the co-channel interference signal; the cancellation signal is added to the output signal from the two-power divider (304) in the second combiner (102) to obtain a signal after the co-channel interference is cancelled; the cancelled signal is sent to the feedback control unit (103), the signal power from the second combiner (102) and the cancellation unit (200) is monitored, and feedback control is performed on the signal preconditioning unit (101) in the parameter precalculation unit (100) and the signal conditioning unit (201) in the cancellation unit (200) to achieve optimal co-channel interference cancellation; The cancellation unit (200) comprises a signal conditioning unit (201), a first combiner (202) and a coupler (203); wherein the signal conditioning unit (201) processes the signal from the three-power divider (301) and outputs a cancellation signal with the same amplitude and opposite phase as the co-frequency interference signal; the cancellation signal is added in the first combiner (202) to the signal output from the two-power divider (304) to obtain a signal after the co-frequency interference is cancelled; and the cancelled signal is sent to the coupler (203); The three-way power divider (301) divides the transmission signal of the external transmitter into three signals with the same components, one of which is sent to the transmitting antenna (302) for transmission, one of which is sent to the parameter pre-calculation unit (100) for generating the cancellation parameters required by the cancellation unit (200), and one of which is sent to the cancellation unit (200) for generating the cancellation signal; The dual power divider (304) divides the mixed signal containing the useful signal and the co-frequency interference signal from the receiving antenna (303) into two paths, and sends them to the elimination unit (200) and the parameter pre-calculation unit (100) respectively; The output end of the signal pre-conditioning unit (101) is connected to the input end of the second combiner (102); the output end of the second combiner (102) is connected to the input end of the feedback control unit (103); the output end of the feedback control unit (103) is respectively connected to the input end of the signal pre-conditioning unit (101) and the input end of the signal conditioning unit (201); The output end of the signal conditioning unit (201) is connected to the input end of the first combiner (202); the output end of the first combiner (202) is connected to the input end of the coupler (203); the output end of the coupler (203) is respectively connected to an external receiver and a feedback control unit (103) in the parameter pre-calculation unit (100); The input end of the three-power divider (301) is connected to an external transmitter; the output end of the three-power divider (301) is respectively connected to a transmitting antenna (302), a parameter pre-calculation unit (100) and an elimination unit (200); the input end of the two-power divider (304) is connected to a receiving antenna (303); and the output end of the two-power divider (304) is respectively connected to the input ends of a second combiner (102) and a first combiner (202).

2. A device for quickly eliminating co-channel interference in a time-varying environment as claimed in claim 1, characterized in that: The transmission signal X(t) outputted from the transmitter is divided into three signals x1(t), x2(t) and x3(t) with the same components through a three-way power divider (301); x1(t) is inputted into a transmission antenna (302) for transmission; x2(t) is inputted into a parameter pre-calculation unit (100) for participating in the calculation of the cancellation signal parameters required for generating the cancellation signal; x3(t) is inputted into an elimination unit (200) for generating the cancellation signal; After the signal r(t) received by the receiving antenna (303) passes through the two power dividers (304), two signals r1(t) and r2(t) with the same components are output; r1(t) is input into the parameter pre-calculation unit (100) for participating in the calculation of the cancellation signal parameters required to generate the cancellation signal; r2(t) is input into the elimination unit (200), and after the elimination unit (200) performs co-channel interference elimination, the interference-eliminated receiving signal y(t) is output; The signal r(t) received by the receiving antenna (303) is output through the two-way power divider (304) as two signals r1(t) and r2(t) with the same components, as shown in the following formula: r1(t)=r2(t)=ax(t-Δt)+u(t) Wherein, ax(t-Δt) is the same-frequency interference signal; u(t) is the useful signal received by the receiving antenna (303); x2(t) is input into a parameter pre-calculation unit (100), signal conditioning is performed in a signal pre-conditioning unit (101), and a pre-cancellation signal c1(t) is output; c1(t) is combined and added with r1(t) in a second combiner (102), and the added signal y'(t) is sent to a feedback control unit (103), and the feedback control unit (103) performs feedback adjustment on the signal pre-conditioning unit (101), so that the signal component of c1(t) and the co-frequency interference signal ax(t-Δt) contained in r1(t) are equal in amplitude and opposite in phase: c1(t)=-ax(t-Δt), thereby achieving addition cancellation in the combiner (102): y'(t)=c1(t)+r1(t)=-ax(t-Δt)+ax(t-Δt)+u(t)=u(t) After the above process, the feedback control unit (103) in the parameter pre-calculation unit (100) obtains the cancellation signal parameters required to generate the cancellation signal, and the cancellation signal parameters are sent to the signal conditioning unit (201) in the elimination unit (200). The signal conditioning unit (201) performs signal conditioning on x3(t) and outputs a cancellation signal c2(t). The signal component of c2(t) is equal in amplitude and opposite in phase to the co-frequency interference signal ax(t-Δt) contained in r2(t): c2(t)=-ax(t-Δt) The co-frequency interference signal contained in r2(t) is added and cancelled with c2(t) in the first combiner (202), and the cancelled signal y(t) is outputted through the output end of the coupler (203), y(t)=c2(t)+r2(t)=-ax(t-Δt)+ax(t-Δt)+u(t)=u(t).

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