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

Abstract

In-band full-duplex wireless, i.e. simultaneous transmission and reception at the same frequency, introduces strong 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 that provides simultaneous downmixing, phase shift and amplitude scaling and subtracts it in the analog baseband for up to 27dB 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-andDistortion-Ratio (SINDR) of up to 71.5dB in 16.25MHz BW. When combined with a two-port antenna with only 20dB isolation, the low RX distortion theoretically allows sufficient digital cancellation for over 90dB link budget, sufficient for short-range, low-power full-duplex links. Index Terms Full-Duplex, Self-Interference, Receiver, Vector Modulator, Distortion, Interference Cancellation

DOI: 10.1109/JSSC.2015.2482495

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Cite this paper

@article{Broek2015AnIF, title={An In-Band Full-Duplex Radio Receiver With a Passive Vector Modulator Downmixer for Self-Interference Cancellation}, author={Dirk-Jan van den Broek and Eric A. M. Klumperink and Bram Nauta}, journal={J. Solid-State Circuits}, year={2015}, volume={50}, pages={3003-3014} }