Self-interference mitigation for in-band mmWave wireless backhaul

Next generation wireless backhaul systems may provide data rates exceeding 10 Gb/s using large bandwidth available at mmWave frequencies, and support features such as point-to-multipoint communication, non-line-of-sight communication, in-band operation (shared spectrum with access) and inter-BS coordination. We explore the feasibility of an “in-band” mmWave wireless base-station with the option of enabling backhaul transmission on one panel while simultaneously receiving access or backhaul on an adjacent panel. We show using simulations and lab measurement validation, that for a prototype 28 GHz mmWave system, the self-interference from the TX sector panel to the adjacent RX panel is around -70 to -80 dB and an additional 35-50 dB isolation is needed for enabling reception on adjacent RX panel that may be achieved through full duplex interference cancellation techniques.