Pragmatic two-level coded modulation using Reed-Solomon product codes

A pragmatic two-level coded modulation scheme based on the direct product of two high-rate single-error-correcting Reed-Solomon (RS) codes is introduced for bandwidthefficient transmission in power-limited systems. The proposed scheme uses a single code/decoder. Data rate flexibility is achieved by simply varying the number of uncoded bits. A simple twostage decoding procedure is described that can operate either on hard- or soft-decisions from the demodulator. A study is carried out in order to optimize the bit-labeling strategy and the minimum Euclidean distance of the code. Simulation results show that the proposed coded modulation scheme exhibits a constant gap to capacity regardless of the cardinality of the signal set. Furthermore this gap can be reduced by considering RS component codes defined over large Galois fields.