Adaptive spatial multiplexing for millimeter-wave communication links

Spatial multiplexing for wireless communication systems is typically used at low GHz carrier frequencies in non Line-of-Sight environments. This dissertation considers adaptive spatial multiplexing for Line-of-Sight wireless links at millimeter-wave carrier frequencies. This architecture provides increased data capacity without increasing the channel bandwidth. The aggregate system data rate scales linearly with the number of transmitter and receiver antenna pairs.System theory and link sensitivity to non ideal installations, multipath signal propagation, and atmospheric refraction are considered. Channel separation hardware implementation considerations are analyzed.Initial work with a two-element prototype using IF channel separation is presented. This prototype achieved 1.2 Gb/s operation over a 6 m indoor link and similar performance for an outdoor link with a 41 m link range.A scalable baseband system architecture is proposed and demonstrated for an indoor link operating over a 5 m link range. The spatially multiplexed channels were separated at the receiver using broadband adaptive analog I/Q vector signal processing. A control loop continuously tuned the channel separation electronics to correct for changes with time in either the propagation environment or the system components. The four-channel 60 GHz hardware prototype achieved an aggregate system data rate of 2.4 Gb/s.