A 30K 2.5Gb/s decision-eased soft RS (224, 216) decoder for wireless systems

In this paper¹, an area efficient (224, 216; 4) soft Reed-Solomon (RS) decoder is provided for wireless systems. According to the Chase-II algorithm, 3 least reliable positions (LRPs) are chosen, and the decoded codeword is determined from 8 (=2³) candidate codewords, leading to 0.5 dB coding gain at 10^-5 BER over the hard RS decoder. Instead of using 8 hard decoders to generate all candidate codewords, our design utilizes only one by reschedule the decoding scheme among all candidate codewords. Therefore, the hardware complexity is significantly reduced. Moreover, the complex decision making unit is eased by using Hamming distance calculation to replace Euclidean distance calculation among all candidate codewords with negligible performance degradation. As compared to low complexity Chase (LCC) soft decoder, our proposed decoder can save around 59.8% complexity. According to the post-layout simulations, the proposed design can achieve 2.5 Gb/s throughput with gate count of 30 K, which is less than one half the normalized area of the hard RS decoder.