System Performance of Indoor Office Millimeter Wave Communications

In order to achieve higher transmission rates and system capacity, fifth-generation cellular (SG) and 802.11ad/ay wireless systems will use higher frequency bands (24GHz-70GHz), the so-called millimeter wave frequencies. These systems rely on using large antenna arrays and narrow beamforming to counter the large path-loss experienced. Narrow beamforming maximizes array gain but results in a significant increase in beam management complexity, and the number of beams which are required to maintain the desired cell coverage as well. Hence, beam-broadening algorithms are suggested as a countermeasure, where a trade-off between high transmission quality and robustness to dynamics could be achieved. In this paper, a novel beam-steering algorithm is proposed to achieve improved coverage for a defined codebook size. Additionally, indoor office system performance is evaluated for different beamforming techniques. Numerical results show up to 1.5 dB improvement in system Signal-to-Interference-plus-Noise Ratio (SINR) via the proposed beam-steering approach when compared to conventional methods. The SINR gains could be converted to a 35% reduction in codebook size. These improvements are attained at zero additional cost.