A Relaxation Oscillator-Based Probabilistic Combinatorial Optimization Engine for Soft Decoding of LDPC Codes

Drawing insights from quantum computing, oscillator-based computing leverages continuous-time operation and massive parallelism to accelerate challenging computational tasks. This work advances the field to demonstrate a Combinatorial Optimization Problem (COP) engine for efficient, robust, one-shot oscillator-based soft decoding of LDPC codes for the first time. We present a 28 nm CMOS prototype that achieves a Frame, Bit Error Rate (FER, BER) of $1.38 \times 10^{-5}, 1.25 \times 10^{-6}$ respectively at 7 dB SNR and an energy efficiency of $5.26 \mathrm{pJ} / \mathrm{bit}$, which surpasses the normalized efficiencies of recent state-of-the-art decoders [1][2][3] by 11x, 3 x, 1.5 x respectively. Tested with more than 100 million frame decodings, the prototype demonstrates consistent performance across a range of SNRs, supply voltages, and temperatures.