Deep Unfolding with Kernel-based Quantization in MIMO Detection
Zeyi Ren, Jingreng Lei, Yichen Jin, Ermo Hua, Qingfeng Lin, Chen Zhang, Bowen Zhou, Yik-Chung Wu
TL;DR
This work tackles energy-efficient MIMO detection for edge devices by marrying deep unfolding with kernel-based adaptive quantization (KAQ). KAQ eliminates reliance on parametric activation distributions through a joint KDE-MMD loss and introduces a dynamic, SNR-aware quantization step size, improving robustness to channel variations. The approach is implemented on PGD-Net and ADMM-Net, achieving BER close to full-precision performance while reducing inference latency by about 20% compared to full precision and outperforming traditional quantization-aware training. The results indicate KAQ's practical potential for deploying accurate, low-latency MIMO detectors in resource-constrained edge environments.
Abstract
The development of edge computing places critical demands on energy-efficient model deployment for multiple-input multiple-output (MIMO) detection tasks. Deploying deep unfolding models such as PGD-Nets and ADMM-Nets into resource-constrained edge devices using quantization methods is challenging. Existing quantization methods based on quantization aware training (QAT) suffer from performance degradation due to their reliance on parametric distribution assumption of activations and static quantization step sizes. To address these challenges, this paper proposes a novel kernel-based adaptive quantization (KAQ) framework for deep unfolding networks. By utilizing a joint kernel density estimation (KDE) and maximum mean discrepancy (MMD) approach to align activation distributions between full-precision and quantized models, the need for prior distribution assumptions is eliminated. Additionally, a dynamic step size updating method is introduced to adjust the quantization step size based on the channel conditions of wireless networks. Extensive simulations demonstrate that the accuracy of proposed KAQ framework outperforms traditional methods and successfully reduces the model's inference latency.
