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arXiv · 1703.10978

Optimal Precoders for Tracking the AoD and AoA of a mm-Wave Path

Nil Garcia·Henk Wymeersch·Dirk Slock
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Abstract

In millimeter-wave channels, most of the received energy is carried by a few paths. Traditional precoders sweep the angle-of-departure (AoD) and angle-of-arrival (AoA) space with directional precoders to identify directions with largest power. Such precoders are heuristic and lead to sub-optimal AoD/AoA estimation. We derive optimal precoders, minimizing the Cram\'{e}r-Rao bound (CRB) of the AoD/AoA, assuming a fully digital architecture at the transmitter and spatial filtering of a single path. The precoders are found by solving a suitable convex optimization problem. We demonstrate that the accuracy can be improved by at least a factor of two over traditional precoders, and show that there is an optimal number of distinct precoders beyond which the CRB does not improve.

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Nil Garcia, Henk Wymeersch, Dirk Slock. 2017-03-31. Optimal Precoders for Tracking the AoD and AoA of a mm-Wave Path. https://doi.org/10.1109/tsp.2018.2870368

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