摘要
针对同频带全双工通信系统存在的自干扰问题,设计完成了一款可集成的单天线同频带全双工自干扰射频抵消系统。同频带全双工系统最关键的问题是:收发机内部发射信号经过不同的路径反射后,通过天线耦合到接收端给接收机带来的强自干扰。由于干扰信号和接收信号位于同一频带内,传统的滤波技术无法将干扰信号滤除,基于正交矢量合成原理,所提可集成自干扰射频抵消技术采用单天线模式,通过自适应控制从发射机获取的两路正交参考信号幅值,合成与自干扰信号幅值相同、相位相同的抵消信号,最后在接收机的射频前端进行相减从而实现自干扰射频抵消。该方法摒弃了限制带宽的相移元件,使得抵消带宽不再严格受限,而且结构简单,易于片上集成,并且采用了自适应控制算法,使得系统工作的适应性更广。系统仿真结果表明,在60 MHz频带内,自干扰射频抵消比均大于41dB。
The realization of single-channel full duplex helps ease the contradiction between the ever-growing requirement for data rate and the extremely scarce spectrum resource.However,the biggest barrier is the strong self-interference when the transmitting signal reflected by different paths is coupled into the weak receiving signal through the antenna.Moreover,traditional filtering techniques cannot filter the interference signal because the interference signal and the received signal reside in the same frequency band.In this paper,a single antenna mode is adopted and an integratable self-interference radio frequency cancelling technique is proposed based on the principle of orthogonal vector synthesis.The cancelling signal that has the same magnitude and phase as the self-interference signal is produced by adaptively controlling the magnitudes of the quadrature reference signals obtained from the transmitter.Finally,the synthesized cancelling signal and the self-interfering signal are subtracted at the radio frequency front end of the receiver to achieve the cancellation effect.This scheme excludes the use of band-limited components,such as phase shifter,so the cancelling bandwidth limitation is completely broken.In addition,it has the advantages of simple architecture and easy single-chip integration.Since this technique uses the adaptive control algorithm,it is more adaptable to different working circumstances.System simulation shows that self-interference rejection up to 41 dB or more could be achieved over a wide bandwidth of 60 MHz.
作者
许江涛
唐炳俊
翟羽健
伍民顺
XU Jiangtao;TANG Bingjun;ZHAI Yujian;WU Minshun(School of Electronic and Information Engineering,Xi’an Jiaotong University,Xi’an 710049,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2018年第9期71-75,108,共6页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(61404102
61306048
61774126)
中央高校基本科研业务费专项资金资助项目
关键词
同频带全双工
自干扰
射频抵消
正交矢量合成
single-channel full duplex
self-interference
radio frequency cancelling
orthogonal vector synthesis
