The performance enhancement of severely impaired unguided laser communication systems using turbo codes

Parallel concatenated convolutionally coded (PCCC) optical binary pulse-position modulation (PPM) communication systems are introduced and investigated. It is assumed that the laser channel is an intensity modulated (IM) channel and that the received optical signal is detected using a shot-noise limited direct-detection (DD) scheme. With the aid of the best available upper bounds, the performance of rate ¹/ _n PCCC encoded optical PPM systems is assessed in terms of the upper bound on the system bit error rate (BER) for shot noise limited IM/DD channels. The numerical results demonstrate the enormous potential of this novel coding scheme in enhancing the performance of the aforementioned optical channel by a sizeable margin across the board