Optimizing Schedulers for Layered BP Decoding: From Code-Specific to Universal Decoding

We show that optimized message update scheduling can enhance both the error-rate performance and the throughput of layered BP decoding of LDPC codes. As an exemplary attempt, optimized scheduling accelerates BP decoding and leads to approximately 2× throughput enhancement when compared to top-to-bottom row-layered BP decoding of 5G LDPC codes. Furthermore, scheduling enhances the error-rate performance of short-length LDPC codes via ensemble decoding. For short-length 5G LDPC codes, coding gains of up to 0.7 dB and 1.6 dB at BLER of 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−3</sup>–10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−4</sup> for both AWGN and Rayleigh fading channels can be achieved when compared to conventional BP decoders. Additionally, we show that the same concept applies to general linear block codes (e.g., polar/RM codes) facilitating a unified decoding architecture based on row-layered BP decoders ("one-silicon fits all").