Two-level coset coding scheme for gigabit Ethernet over plastic optical fibre

The present invention relates to an efficient coding and modulation system for transmission of digital data over plastic optical fibres with low latency. In particular, the digital signal is coded by means of a two-level coset coding. The first level applies to the digital data of a binary shortened BCH coding and performs coset partitioning by means of constellation mapping and lattice transformations. The second level is uncoded but undergoes mapping and lattice transformation. After an addition of the two levels, a second-stage lattice transformation is performed so as to obtain a zero-mean constellation. The symbols output from such two-level coset coder are then further modulated.