Analysis of ADC Quantizing Affection on SER Performance of Self-interference Canceling Common-frequency Full-duplex System

Common-frequency full-duplex systems send and receive signals simultaneously in the same frequency.Therefore,self-interference will exist in the local receiver and interference cancellation is necessary.Digital interference cancellation is applied after Analog-to-Digital Converter(ADC) sampling.ADC bit number,Interference-to-Signal Ratio(ISR),and quantizing judgment scheme affect both interference cancellation and Symbol Error Ratio(SER).In this paper,the essential relationship among ADC bit number,ISR,and SER of Quadrature Amplitude Modulation(QAM) is analyzed;A closed-form expression of SER is developed;And simulation results are presented to support the SER expression.The simulation results show that: when ISR decreases or ADC bit number increases,SER of this kind of system decreases in large scale,and fluctuates in small scale;some fluctuations of SER are dramatic,which can approach to the SER of the system without quantization error.