Reusing a Single AWGN Code for Multiple Fading Streams via Random Multiplexing and Joint Detection-Decoding

Abstract

Altering the quantity or structure of AWGN codes for multiple fading streams is often challenging due to the inflexibility and high cost of ASICs. To circumvent this bottleneck, this work introduces a framework to reuse a single standard AWGN code while ensuring reliable performance. Specifically, transmitter-side random multiplexing (RM) approximates an equivalent AWGN channel, while receiver-side cross-domain orthogonal approximate message passing (CD-OAMP) enables relatively low-complexity detection, collectively unlocking joint detection-decoding gains. Furthermore, this work characterizes the achievable rates and limits predicted by state evolution (SE) under specific scheme constraints. Simulations validate the framework across multiple fading streams within single AWGN code architectures.