Joint synchronization and decoding for photon-limited optical channels: Code design and complexity reduction

The problem of joint symbol synchronization and decoding of pulse position modulation (PPM) sequences in the deep-space photon-limited optical channel is considered. A new joint synchronizer and decoder for PPM on this channel is presented along with the design of codes having both good error control and synchronization properties for use with PPM signaling on this channel. The new approach presented in this paper provides a significant reduction in synchronizer/decoder complexity when compared to previous methods for joint synchronization and decoding.