Study on performance of M-ary PPM underwater optical communication systems using vector radiative transfer theory

The frequency response model for the underwater wireless optical communication channel is obtained using the discrete ordinates method based on vector radiative transfer theory. And the performance of a 1Gb/s communication system with M-ary PPM has been evaluated by applying this frequency response model. The results show that with the increase of transmission distance the bit-error-rate performance degrades, and the field of view (FOV) has a different behaviour in terms of bit-error-rate performance as distance increases. In short distance, with the increase of FOV the bit-error-rate performance degrades, and in long distance, it is opposite. The 4-PPM bit-error-rate performance is almost equal to that of OOK modulation. 8-PPM or 16-PPM can be used to get more improvement in bit-error-rate performance and higher power efficiency.