1 research outputs found
Hybrid Precoding Based on Non-Uniform Quantization Codebook to Reduce Feedback Overhead in Millimeter Wave MIMO Systems
In this paper, we focus on the design of the hybrid analog/digital precoding
in millimeter wave multiple-input multiple-output (MIMO) systems. To reduce the
feedback overhead, we propose two non-uniform quantization (NUQ) codebook based
hybrid precoding schemes for two main hybrid precoding implementations, i.e.,
the full-connected structure and the sub-connected structure. Specifically, we
firstly group the angles of the arrive/departure (AOAs/AODs) of the scattering
paths into several spatial lobes by exploiting the sparseness property of the
millimeter wave in the angular domain, which divides the total angular domain
into effective spatial lobes' coverage angles and ineffective coverage angles.
Then, we map the quantization bits non-uniformly to different coverage angles
and construct NUQ codebooks, where high numbers of quantization bits are
employed for the effective coverage angles to quantize AoAs/AoDs and zero
quantization bit is employed for ineffective coverage angles. Finally, two
low-complexity hybrid analog/digital precoding schemes are proposed based on
NUQ codebooks. Simulation results demonstrate that, the proposed two NUQ
codebook based hybrid precoding schemes achieve near-optimal spectral
efficiencies and show the superiority in reducing the feedback overhead
compared with the uniform quantization (UQ) codebook based works, e.g., at
least 12.5% feedback overhead could be reduced for a system with 144/36
transmitting/receiving antennas.Comment: 29 pages, 12 figure