  Rapid beam alignment is required to support high gain millimeter wave (mmW)
communication links between a base station (BS) and mobile users (MU). The
standard IEEE 802.11ad protocol enables beam alignment at the BS and MU through
a lengthy beam training procedure accomplished through additional packet
overhead. However, this results in reduced latency and throughput. Auxiliary
radar functionality embedded within the communication protocol has been
proposed in prior literature to enable rapid beam alignment of communication
beams without the requirement of channel overheads. In this work, we propose a
complete architectural framework of a joint radar-communication wireless
transceiver wherein radar based detection of MU is realized to enable
subsequent narrow beam communication. We provide a software prototype
implementation with transceiver design details, signal models and signal
processing algorithms. The prototype is experimentally evaluated with realistic
simulations in free space and Rician propagation conditions and demonstrated to
accelerate the beam alignment by a factor of four while reducing the overall
bit error rate (BER) resulting in significant improvement in throughput with
respect to standard 802.11ad. Likewise, the radar performance is found to be
comparable to commonly used mmW radars.
