Parallel Generation of Most Reliable LLRs of a Non-Binary Symbol
Hassan Harb, Ali Chamas Al Ghouwayel, Emmanuel Boutillon · IEEE Communications Letters · 2019
The first task of non-binary (NB) decoders [low-density parity check (LDPC) or turbo] is to generate the log-likelihood ratio (LLR) of the received NB symbols defined over Galois fields GF(q > 2). In the extended min-sum decoding algorithm, the intrinsic information associated to a given received symbol is a sorted list of the Tim most reliable NB GF symbols along with their associated reliability values. In this letter, we present a fully parallel LLR generation algorithm, an enabler for very high throughput decoding that processes one received symbol per clock cycle. We provide complexity figures for LLR architectures designed over GF(q) of sizes 64, 256, and 1024, as well as different values of nm. Compared with the related state-of-the-art architecture, field-programmable gate array (FPGA) synthesis results show that the proposed parallel architecture improves the hardware efficiency by a factor ranging from 7 up to 15.