Physical Layer Interference Mitigation Technology In60GHzWireless Networks

Under the condition that the demands on wireless communications are growing with the development of technology while there is less and less available spectrum,60Ghz wireless system is attracting a growing interest for its5-7GHz available unlicensed bandwidth. Several GHz channel bandwidth, high propagation loss and high penetration loss makes60GHz system a very good choice to build short range gigabit wireless systems. As there are only2-4channels at60GHz band, interference mitigation technologies are needed in multi-user scenarios for spatial reuse. But at present, most of the achievements made in60GHz interference mitigation are at the MAC layer, while low complexity and high feasibility results are needed in physical layer.This paper studied the physical layer interference mitigation technologies in60GHz systems, valuable achievements are made in this paper, including some new interference mitigation methods, and beamforming schemes with high feasibility and low complexity. In60GHz systems, large antenna arrays are usually used to achieve high directional gain to compensate for the high path loss at this band. An interference alignment scheme based on sub-array partition is proposed in this paper. Due to the simulation results, this scheme could reach much higher channel capacity in high signal to noise rate scenarios. And then, a mixed analog-digital beam-forming scheme which is also based on subarray partition is proposed. This scheme maintained the simple antenna structure in IEEE802.15.3c codebook based beamforming method, and the system performance against interference could be significantly improved with only1additional radio frequency chain.