Self-Interference Cancellation Applied To Full Duplex Communication

With the development of wireless communication industry, used in the wireless communication signal bandwidth are more and more wide, but the corresponding spectrum is less and less. Currently, wireless communication has developed from FDMA to TDMA, and now CDMA, people have been studying save spectrum resources and maximize the use of spectrum algorithm and technology, so, at the same time and same band full-duplex communication comes. In full-duplex communication, self-interference cancellation is the key technique cause. Because of Sending and receiving information are at the same time, the received signal contains a great power from the self interference signal, which will be harmful to the receiver system. Not only useful information is lost in the strong interference signals, but also the low noise amplifier is close to saturation which the receiving system hardware will be damage. Therefore, to achieve full-duplex communication, there must be a self interference cancellation.This paper focuses on the same frequency at the same time full-duplex communication’s self-interference cancellation techniques. The self-interference cancellation technology contains analog and digital interference cancellation. The analog self-interference in the radio frequency means for receiving the analog signal from the end of the interference canceller, the digital interference cancellation means after receiving the information from the digital domain interference canceller. This paper studies the impact of innovative simulation of the effect of self-interference cancellation signal amplitude and phase conditions and derive the complete formula. This paper improved the architecturethe of existing analog self-interference and design the hardware circuit for the actual verification, eventually combined with full-duplex transceiver carrying on full-duplex communication testing for2-3m in close conditions and taking a good result. This paper also presents innovative power measurement and loop-based delay calculation interference cancellation algorithms, the digital filter algorithms than existing methods enhance digital interference cancellation5dB nearly and Lay a good foundation for the future study.