Scalable subband subsampled radio architecture for millimetre wave communications with performance analysis

Millimetre wave bands are envisaged to be utilised for next generation ultra-high data rate communications due to the availability of large bandwidths. However, high sampling rate requirement at these frequencies leads to significant power consumption in the devices. In this study, a subband-based subsampled radio architecture is proposed for indoor millimetre wave communications with the objective of improving power efficiency along with scalable data rates and multi-user support under varying Quality of Service (QoS) requirements. An optimum bandwidth partitioning scheme is presented to support the proposed architecture. Subbanding in association with orthogonal spreading codes enables the reduction of sampling rate requirement at the receiver, resulting in significant power savings for medium data rate communication systems. Furthermore, the performance evaluation of the scheme is performed by deriving closed-form analytical expressions for probability of bit error under line-of-sight (LOS) and non-LOS conditions considering the effect of antenna half-power beamwidth. The analytical expressions and simulation results for different requirements including maximum data rate, variable number of users, and variable QoS are evaluated and compared.