User Scheduling for Millimeter Wave MIMO Communications with Low-Resolution ADCs

TL;DR

This paper explores uplink user scheduling in millimeter wave MIMO systems with low-resolution ADCs, emphasizing the importance of beamspace channel structure to maximize sum rates and proposing an efficient scheduling algorithm.

Contribution

It introduces a novel scheduling criterion based on beamspace channel structure and develops an efficient algorithm for mmWave systems with low-resolution ADCs.

Findings

The proposed algorithm outperforms conventional methods in sum rate.

Channel structure in beamspace significantly impacts achievable rates.

Optimal scheduling criteria are derived considering quantization effects.

Abstract

In millimeter wave (mmWave) systems, we investigate uplink user scheduling when a basestation employs low-resolution analog-to-digital converters (ADCs) with a large number of antennas. To reduce power consumption in the receiver, low-resolution ADCs can be a potential solution for mmWave systems in which many antennas are likely to be deployed to compensate for the large path loss. Due to quantization error, we show that the channel structure in the beamspace, in addition to the channel magnitude and beamspace orthogonality, plays a key role in maximizing the achievable rates of scheduled users. Consequently, we derive the optimal criteria with respect to the channel structure in the beamspace that maximizes the uplink sum rate for multi-user multiple input multiple output (MIMO) systems with a zero-forcing receiver. Leveraging the derived criteria, we propose an efficient scheduling algorithm for mmWave systems with low-resolution ADCs. Numerical results validate that the proposed algorithm outperforms conventional user scheduling methods in terms of the sum rate.