PROJECT TITLE :

An In-Band Full-Duplex Radio Receiver With a Passive Vector Modulator Downmixer for Self-Interference Cancellation

ABSTRACT:

In-band full-duplex (FD) wireless, i.e., simultaneous transmission and reception at the same frequency, introduces sturdy self-interference (SI) that masks the signal to be received. This paper proposes a receiver in which a copy of the transmit signal is fed through a switched-resistor vector modulator (VM) that has simultaneous downmixing, phase shift, and amplitude scaling and subtracts it in the analog baseband for up to twenty seven dB SI-cancellation. Cancelling before active baseband amplification avoids self-blocking, and highly linear mixers keep SI-induced distortion low, for a receiver SI-to-noise-and-distortion-ratio (SINDR) of up to 71.five dB in sixteen.twenty five MHz BW. When combined with a two-port antenna with only twenty dB isolation, the low RX distortion theoretically permits sufficient digital cancellation for over 90 dB link budget, sufficient for brief-vary, low-power FD links.