Performance Improvement for OFDM-RoF Transported 60 GHz System using Spatial Diversity and Multiplexing

60 GHz system architectures with Radio over Fiber (RoF) transport and integrated transmitters/receivers provide a comprehensive solution for future mobile systems. Since 60 GHz communication relies on line-of-sight (LoS) conditions and narrow-beam antennas to compensate the high path-loss, it has limitations in terms of coverage for multiple user locations. In this paper, performance analysis of a 60 GHz integrated transmitter and receiver system supported by RoF transport has been performed experimentally at different user locations for up to 1.5m transmission distance. Extension of experimental results to prove feasibility for longer distances has been shown with a simulation model, whose results at various shorter distances have been benchmarked against the acquired experimental results at different user locations. A modified version of the Saleh Valenzuela channel has been used to model the millimeter wave (mmW) LoS indoor experimental environment. Furthermore, as a proof of concept, we present an experimental analysis demonstrating an improvement in performance of the proposed RoF based 60 GHz system using spatial diversity and multiplexing. Channel measurements at different transmitter/receiver locations and their processing have shown that an improvement (decrease from 12.5% to 10.5%) in Error Vector Magnitude (EVM) can be achieved using the Alamouti Space Time Block Coding algorithm. Then it has been shown that a two-fold data rate increase can be obtained by combining data from two transmitter locations using the Zero Forcing algorithm.