Study on new scheme of byte-wise interleaving and convolutional coding for high-data-rate optical wireless communication system

Increasing interleaving depth can mitigate the impact of long deep fade induced by atmospheric turbulence. A new scheme of a FEC coding with large-depth interleaving was proposed. The transmitter was designed using an m-stage interlaced convolutional coding in combination with byte-wise interleaving; correspondingly the receiver performed word-wise deinterleaving and parallel soft-decision Viterbi decoding based on logarithmic quantization of channel input. Furthermore, a rule of byte combination was analyzed and a new configuration of co-prime byte-wise convolutional interleaving was presented. The results show that the new scheme reduces the complexity and the speed requirement of system design. Compared with the optimum threshold detection at a BER of 10-6, coding gains of 6. 9dB were achievable by the new scheme at source data rates of 300 Mbit/s. The loss with respect to perfect interleaving is only 0.3 dB, Hence, the new scheme is superior in high-data-rate optical wireless communication system.EI01038-43+472