Syndrome selective decoding of modulo-M convolutional coded optical PPM

A syndrome selective decoding of modulo-M convolutional coded M-ary pulse position modulation (PPM) in photon communications is presented. In the decoding, the erasure symbol is corrected by using one of the reliable syndromes. The decoder allows high reliability transmission at high-speed deep space and inter-satellite optical communication links. The upper and lower bounds of the bit error probability of the decoder are derived for rate 1/2 self-orthogonal convolutional codes. It is found that modulo-M coded PPM combined with decoding provides substantial performance improvement in photon communication systems