Interference mitigation in mm-wave backhaul networks with limited channel-state information

Our goal is to identify if limited channel-state information is sufficient to mitigate interferences between the stations of a wireless mobile backhaul network, which is especially of great importance if the network employs full-duplex operation or terrestrial and satellite links sharing the same spectrum. We analyze and compare the signal-to-interference-and-noise ratio of plain beam steering and zero-forcing beam steering for a millimeter-wave backhaul network with limited channel-state information where only the positions of the stations are known, while buildings and other possible sources of multipath components are unknown. Numerical analyses based on raytracing in a realistic urban scenario reveal that zero-forcing beam steering outperforms plain beam steering by about 12 dB. Furthermore, we compare the steering approaches to block diagonalization with full channel-state information as a reference. For situations with low signal-to-noise ratio as in wide-band communications, zero-forcing beam steering can achieve a similar signal-to-noise-and-interference ratio to block diagonalization. We conclude that knowing the positions of wireless backhaul stations obviates the need for expensive channel estimation.