Low-Latency Ordered Statistics Decoding of BCH Codes

This paper proposes a low-latency ordered statistics decoding (OSD) algorithm for BCH codes. The OSD latency is mainly caused by Gaussian elimination (GE) that produces a systematic generator matrix of the code. Considering BCH codes is binary subcodes of Reed-Solomon (RS) codes, we show that the BCH codeword candidates can be produced through the systematic generator matrix of the corresponding RS code. The systematic generator matrix of an RS code can be formed by generating the linearly independent RS codewords in parallel, replacing the GE process and enabling a low OSD latency. This paper further proposes a segmented variant that facilitates the decoding by reducing the number of test error patterns (TEPs). Complexity of the proposed OSD is also analyzed. Our simulation results show that the proposed decoding can achieve a similar performance as the conventional OSD, but with a lower decoding complexity. The decoding latency can be reduced over the conventional OSD substantially.