Achievable Throughput of Multi-mode Multiuser MIMO with Imperfect CSI Constraints

TL;DR

This paper derives achievable rates for multi-user MIMO broadcast channels with imperfect, delayed, and quantized CSI, proposing an adaptive multi-mode transmission strategy to optimize throughput while managing inter-user interference.

Contribution

It introduces a novel multi-mode transmission strategy that adaptively adjusts active users based on channel statistics to maximize throughput under imperfect CSI conditions.

Findings

Supporting too many users increases residual interference.

Adaptive mode selection improves throughput.

Derived achievable ergodic rates for delayed and quantized CSI.

Abstract

For the multiple-input multiple-output (MIMO) broadcast channel with imperfect channel state information (CSI), neither the capacity nor the optimal transmission technique have been fully discovered. In this paper, we derive achievable ergodic rates for a MIMO fading broadcast channel when CSI is delayed and quantized. It is shown that we should not support too many users with spatial division multiplexing due to the residual inter-user interference caused by imperfect CSI. Based on the derived achievable rates, we propose a multi-mode transmission strategy to maximize the throughput, which adaptively adjusts the number of active users based on the channel statistics information.