New Beam Tracking Technique for Millimeter Wave-band Communications

Abstract

In this paper, we propose an efficient beam tracking method for mobility scenario in mmWave-band communications. When the position of the mobile changes in mobility scenario, the base-station needs to perform beam training frequently to track the time-varying channel, thereby spending significant resources for training beams. In order to reduce the training overhead, we propose a new beam training approach called "beam tracking" which exploits the continuous nature of time varying angle of departure (AoD) for beam selection. We show that transmission of only two training beams is enough to track the time-varying AoD at good accuracy. We derive the optimal selection of beam pair which minimizes Cramer-Rao Lower Bound (CRLB) for AoD estimation averaged over statistical distribution of the AoD. Our numerical results demonstrate that the proposed beam tracking scheme produces better AoD estimation than the conventional beam training protocol with less training overhead.

Fast Analog Beam Tracking in Phased Antenna Arrays: Theory and Performance

“…But the optimal probing directions are not given in these algorithms. In [44], the authors start to study the optimization of analog beamforming vectors during pilot training, which is obtained based on the latest estimate. However, its beam direction estimation is done without using the historical estimation information.…”

High-Resolution Angle Tracking for Mobile Wideband Millimeter-Wave Systems With Antenna Array Calibration

“…Grid-of-beams based beam training is the defacto approach for configuring transmit and receive beams; variations are used in IEEE 802.11ad systems [6], [7] and will be used in 5G [8]. Beam tracking approaches that support grid-of-beams have been developed in [6], [7], [9], [10], but the performance depends on the grid resolution, leading to high complexity, tracking overhead, and access delay. In [11], [12], a priori-aided angle tracking strategies were proposed.…”

Analog beam tracking in linear antenna arrays: Convergence, optimality, and performance

“…There has been a number of recent studies on beam direction estimation/tracking for analog beamforming [10]- [16]. In [10]- [14], one round of beam sweeping, scanning many spatial beam directions in a codebook, is needed for updating the beam direction estimate.…”

“…In [10]- [14], one round of beam sweeping, scanning many spatial beam directions in a codebook, is needed for updating the beam direction estimate. In [15], [16], the training is performed based on knowledge of prior beam estimates, which is beneficial to save pilots. However, the optimal training has not been obtained and the estimation/tracking is not optimized accordingly, which leads to poor tracking accuracy.…”