Study on intra-symbol interleaving for Multi-Non-Binary Turbo Codes

Multi-Non-Binary Turbo Codes (MNBTC), i.e. the latest generation of turbo codes, operate with arrays of symbols, each symbol consisting of several bits. The interleaving for these multi-binary arrays of symbols required in turbo coding involves two steps: an inter-symbol interleaving and an intra-symbol interleaving. Inter-symbol interleaving mixes the data arrays columns. This can be achieved by using already existing dedicated interleavers. The novelty is intra-symbol interleaving, mixing symbols or even bits in each column of the data array. This paper investigates several possible intra-symbol interleaving methods in terms of their bit/frame error rate versus signal to noise ratio (BER/FERvsSNR) performances. The study allows some practical conclusions.