True-Time-Delay Large Scale Array for Next-Generation Wireless

Owing to the large propagation losses at mm-wave, multi-antenna systems are needed for improved signal-to-noise ratio (SNR) and link quality. However, the resulting narrow-pointed beams necessitate fast beam acquisition especially for communication applications on-the-move. To acquire fast channel state information (CSI), maximize the received power, and fully benefit from the beamforming technology, a process known as beam training is widely adopted to search for the optimal angles to direct the beams. The existing beam training methodologies pose numerous challenges toward low latency, power consumption, and cost for both the base station (BS) and the user equipment (UE). In this tutorial, we will describe a reconfigurable true-time-delay (TTD)-based spatial-signal-processor (SSP) with a frequency-division beam training methodology and wideband beam-squint-less data communications leveraging a discrete-time delay compensated clocking technique. The integrated delay compensation provides GHz bandwidths supported by a large unity-gain bandwidth ring-amplifier (RAMP)-based signal combiner. The talk further describes an automated testbed for SSP mode characterization leveraging computer vision techniques for fast testing and minimization of human errors.