A High-Throughput Constructive Interference Precoder for 16 × MU-MIMO Systems
Journal
IEEE Transactions on Very Large Scale Integration (VLSI) Systems
Journal Volume
32
Journal Issue
10
Start Page
1878
End Page
1888
ISSN
1063-8210
1557-9999
Date Issued
2024-10
Author(s)
Abstract
In a multiuser multiple-input multiple-output (MU-MIMO) downlink system, users are susceptible to interuser interference (IUI) because of data being simultaneously transmitted over the same time-frequency resources. Conventionally, precoding algorithms aim to eliminate the IUI. However, constructive interference (CI) precoding can achieve better error performance by exploiting the IUI. This article presents a high-throughput CI precoder. Design optimization across the algorithm and the architecture layers is conducted, reducing the complexity for multiplications by 81.6%. As the number of iterations for convergence varies, dynamic resource allocation is utilized to support each modulation mode with maximized utilization: time-multiplexing for the 4-QAM mode and parallel-processing for the 16-QAM mode. The proposed symbol updater also allows more efficient scheduling. As a proof of concept, a CI precoder chip that supports up to 16 × MU-MIMO systems is designed based in a 40-nm CMOS technology. The performance gains at a bit error rate (BER) = 10-4 are 10.7 and 12.5 dB for 4-QAM and 16-QAM, respectively, compared with conventional regularized zero-forcing (RZF) schemes. The precoder delivers a maximum throughput of 3.2 Gb/s at a clock frequency of 200 MHz for the 16 × MU-MIMO configuration.
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Type
journal article