A 95.5Gb/s 29.6ns worst-case latency ORBGRAND decoder for 6G xURLLC

Abstract: Ultra-Reliable Low-Latency Communications (URLLC) in both 5G and 6G demand high throughput and short latency with low error rates. Guessing Random Additive Noise Decoding (GRAND) and Ordered Reliability Bits GRAND (ORBGRAND) are powerful universal decoding algorithms that work well with short, high-rate codes. As short forward error correcting codes can help limiting latency, and code unification in 6G calls for flexible, possibly code-agnostic decoders, GRAND and ORBGRAND are well suited to tackle 6G URLLC. This work proposes a ultra-high, constant speed ORBGRAND decoder architecture with very low worst-case and average latency. Compared to a baseline architecture, through out-of-order output, aggressive clock gating, and selective programmability, the decoder reduces area, power, and average latency by 15.5%, 19.4%, and 56%, respectively. In 3nm FinFET technology, it achieves a constant throughput of 95.49Gb/s, with 29.59ns worst-case latency and 13.02ns on average.