Low-complexity decoders for non-binary turbo codes

Following the increasing interest in non-binary coding schemes, turbo codes over different Galois fields have started to be considered recently. While showing improved performance when compared to their binary counterparts, the decoding complexity of this family of codes remains a main obstacle to their adoption in practical applications. In this work, a new low-complexity variant of the Min-Log-MAP algorithm is proposed. Thanks to the introduction of a bubble sorter for the different metrics used in the Min-Log-MAP decoder, the number of required computations is significantly reduced. A reduction by a factor of 6 in the number of additions and compare-select operations can be achieved with only a minor impact on error rate performance. With the use of an appropriate quantization, the resulting decoder paves the way for a future hardware implementation.