Adaptive radio-frequency interference cancelling device, method, and receiver

Abstract

The present invention provides an adaptive radio-interference cancelling device and method, a receiver, and a wireless full duplex communication system. The device includes an amplitude phase adjusting module, configured to adjust an amplitude and a phase of a radio-frequency reference signal and output a radio-frequency adjustment signal to enable the radio-frequency adjustment signal to converge to a self-interference signal in a radio-frequency received signal; a subtractor, configured to output a radio-frequency residual signal, where the radio-frequency residual signal is a difference signal between the radio-frequency received signal and the radio-frequency adjustment signal; and a baseband extracting and filtering module, configured to receive the radio-frequency reference signal and the radio-frequency residual signal output by the subtractor, extract baseband signals and perform least mean squares adaptive filtering processing on the baseband signals to obtain an amplitude phase control signal and output to the amplitude phase adjusting module.

What is claimed is: 
     
       1. An adaptive radio-frequency interference cancelling device, comprising:
 an amplitude phase adjusting module, configured to adjust an amplitude and a phase of a radio-frequency reference signal, output a radio-frequency adjustment signal to a subtractor, to enable the radio-frequency adjustment signal to converge to a self-interference signal in a radio-frequency received signal; 
 the subtractor, configured to receive the radio-frequency received signal and the radio-frequency adjustment signal output by the amplitude phase adjusting module, and output a radio-frequency residual signal, wherein the radio-frequency residual signal is a difference signal between the radio-frequency received signal and the radio-frequency adjustment signal; and 
 a baseband extracting and filtering module, configured to receive the radio-frequency reference signal and the radio-frequency residual signal output by the subtractor, extract baseband signals and perform least mean squares adaptive filtering processing on the baseband signals to obtain an amplitude phase control signal and output to the amplitude phase adjusting module, wherein the amplitude phase control signal is used to control the amplitude phase adjusting module to adjust the amplitude and the phase of the radio-frequency reference signal. 
 
     
     
       2. The device according to  claim 1 , wherein the baseband extracting and filtering module comprises a first multiplier, a first low-pass filter, a phase shifter, a second multiplier, a second low-pass filter, and a least mean squares adaptive filtering processing module, the radio-frequency reference signal is split into two signals, of which one is mixed with the radio-frequency residual signal by the first multiplier and passes through the first low-pass filter to obtain a first baseband product signal, and the other split radio-frequency reference signal is phase-shifted by 90 degrees via the phase shifter, then mixed with the radio-frequency residual signal by the second multiplier and filtered by the second low-pass filter to obtain a second baseband product signal, and the first baseband product signal and the second baseband product signal are input to the least mean squares adaptive filtering processing module to generate the amplitude phase control signal used to control the amplitude phase adjusting module. 
     
     
       3. The device according to  claim 2 , wherein the amplitude phase control signal is an adjustment coefficient signal, and the amplitude phase adjusting module adjusts the amplitude and the phase of the radio-frequency reference signal according to the received adjustment coefficient signal. 
     
     
       4. A receiver, comprising a receiving antenna, a low noise amplifier, a down-converter, an analog-to-digital converter, a digital interference cancelling device, and a reception digital signal processor, wherein the receiver further comprises an adaptive radio-frequency interference cancelling device according to  claim 1 , the receiving antenna, the adaptive radio-frequency interference cancelling device, the low noise amplifier, the down-converter, the analog-to-digital converter, the digital interference cancelling device, and the reception digital signal processor are connected sequentially, and the adaptive radio-frequency interference cancelling device is further input with a radio-frequency reference signal from a transmitter and the digital interference cancelling device is further input with a digital reference signal from the transmitter. 
     
     
       5. A wireless full duplex communication system, comprising a transmitter, wherein the transmitter comprises a transmission digital signal processor, a digital-to-analog converter, an up-converter, a power amplifier and a transmitting antenna that are connected sequentially, wherein the system further comprises a receiver according to  claim 4 , a radio-frequency reference signal output by the power amplifier is input to an adaptive radio-frequency interference cancelling device of the receiver, a digital reference signal output by the transmission digital signal processor is input to a digital interference cancelling device of the receiver. 
     
     
       6. An adaptive radio-frequency interference cancelling method, comprising:
 adjusting an amplitude and a phase of a radio-frequency reference signal and outputting a radio-frequency adjustment signal, to enable the radio-frequency adjustment signal to converge to a self-interference signal in a radio-frequency received signal; 
 obtaining a radio-frequency residual signal, wherein the radio-frequency residual signal is a difference signal between the radio-frequency received signal and the radio-frequency adjustment signal; and 
 receiving the radio-frequency residual signal and the radio-frequency reference signal, extracting baseband signals, and performing least mean squares adaptive filtering processing on the baseband signals to obtain an amplitude phase control signal, wherein the amplitude phase control signal is used to control adjustment of the amplitude and the phase of the radio-frequency reference signal. 
 
     
     
       7. The method according to  claim 6 , wherein the receiving the radio-frequency residual signal and the radio-frequency reference signal, extracting baseband signals, and performing least mean squares adaptive filtering processing on the baseband signals to obtain an amplitude phase control signal, specifically comprises:
 splitting the radio-frequency reference signal into two signals, mixing one of the two split signals with the radio-frequency residual signal and performing low-pass filtering to obtain a first baseband product signal; 
 phase-shifting the other split radio-frequency reference signal by 90 degrees, mixing with the radio-frequency residual signal and performing low-pass filtering to obtain a second baseband product signal; and 
 performing least mean squares adaptive filtering processing on the first baseband product signal and the second baseband product signal to generate the amplitude phase control signal, wherein the amplitude phase control signal is used to control the adjustment of the amplitude and the phase of the radio-frequency reference signal.