Optimal Precoders for Tracking the AoD and AoA of a mmWave Path

• 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 suboptimal AoD/AoA estimation. We derive optimal precoders, minimizing the Cramér–Rao bound (CRB) of the AoD/AoA under a given uncertainty range, 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.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Signalbehandling (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Signal Processing (hsv//eng)

Keyword

antenna arrays

array signal processing

Uncertainty

Transmitters

precoding

Millimeter wave communication

Receivers

Radar tracking

optimization

Signal to noise ratio

Channel estimation

Cramér–Rao bounds

antenna radiation patterns

Estimation

Publication and Content Type

art (subject category)

ref (subject category)