Reduced-Feedback Hybrid Precoding for Wideband mmWave MIMO-OFDM Systems

2026-05-04

AI Summary

This work addresses the high cost of radio-frequency chains and the substantial channel state information (CSI) feedback overhead in large-scale millimeter-wave MIMO-OFDM systems by proposing an efficient hybrid precoding scheme. The approach constructs a frequency-flat analog precoder and integrates angle-domain sparsity modeling, Lloyd quantization codebook design, binary-search hierarchical interpolation, and subcarrier correlation-aware adaptive allocation to achieve low-complexity precoding. A novel sublinear feedback mechanism reduces feedback complexity from O(K) to O(K/M + log M), significantly lowering overhead while enhancing robustness. Experimental results demonstrate that the proposed method achieves spectral efficiency and bit error rate performance comparable to or better than existing schemes, maintaining robust operation even under imperfect CSI conditions.

Abstract

In this paper, we propose a feedback-efficient hybrid precoding framework for wideband millimeter-wave (mmWave) multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems. To mitigate the high cost of radio frequency (RF) chains and channel state information (CSI) feedback in large-scale antenna arrays, we first construct frequency-flat analog precoders by extracting dominant angle-of-arrival (AoA) and angle-of-departure (AoD) directions from sparse frequency-domain channels. For digital precoding, we design a quantized codebook using the Lloyd algorithm and develop a binary-search-based hierarchical interpolation algorithm that adaptively assigns codewords according to subcarrier correlation. The proposed method achieves sub-linear feedback scaling by reducing the feedback overhead from O(K) to O(K/M + log M), where K is the number of subcarriers and M is the pilot spacing. Simulation results demonstrate that the proposed method achieves comparable or superior spectral efficiency and bit error rate (BER) performance to existing clustering and interpolation schemes, while significantly reducing computational complexity and exhibiting robustness under imperfect CSI.

Problem

• mmWave
• MIMO-OFDM
• hybrid precoding
• CSI feedback
• wideband

Innovation

• Hybrid Precoding
• mmWave MIMO-OFDM
• Reduced Feedback
• Angle Extraction
• Hierarchical Interpolation