LOREN: Low Rank-Based Code-Rate Adaptation in Neural Receivers
Bram Van Bolderik, Vlado Menkovski, Sonia Heemstra de Groot, Manil Dev Gomony
TL;DR
LOREN addresses the memory and power burden of neural receivers that must support multiple code rates by freezing a shared base network and learning small, per-code-rate low-rank adapters. These adapters, applied via lightweight 1×1 updates, enable dynamic code-rate adaptation with negligible parameter overhead while achieving performance on par with or better than full retraining. End-to-end training over realistic 3GPP CDL channels demonstrates robust BLER performance across CRs, and hardware synthesis in 22nm FD-SOI shows significant area (over 65%) and power (up to 15%) reductions when supporting three CRs. The approach offers scalable, energy-efficient neural reception suitable for multi-CR wireless systems and paves the way for extending such adapters to broader modulation schemes and hyperparameter regimes.
Abstract
Neural network based receivers have recently demonstrated superior system-level performance compared to traditional receivers. However, their practicality is limited by high memory and power requirements, as separate weight sets must be stored for each code rate. To address this challenge, we propose LOREN, a Low Rank-Based Code-Rate Adaptation Neural Receiver that achieves adaptability with minimal overhead. LOREN integrates lightweight low rank adaptation adapters (LOREN adapters) into convolutional layers, freezing a shared base network while training only small adapters per code rate. An end-to-end training framework over 3GPP CDL channels ensures robustness across realistic wireless environments. LOREN achieves comparable or superior performance relative to fully retrained base neural receivers. The hardware implementation of LOREN in 22nm technology shows more than 65% savings in silicon area and up to 15% power reduction when supporting three code rates.
