Transfer Transmission Performance of Differential Multi pulse Position Modulation in Optical Communication
To needs the requirement of space optical communication network, a high speed laser communication in satelite links is necessary, and the modulation technology is the basis of large capacity and wide band communication. In this paper, a novel differential multi pulse position modulation scheme is proposed to reduce the bandwidth requirement and increase the transmission rate. Firstly, based on the theory of pulse position modulation, combined with the characteristic of differential pulse position modulation (DPPM) a differential multi pulse position modulation (DMPPM) scheme model is established by introducing the multi pulse position modulation (MPPM) mode. Based on the character of the symbol structure of the model, the unit transmission rate equation of DMPPM is derived, and the bandwidth requirement model is established according to Gauss channel Shannon formula. Finally, based on the established model, the transmission characteristics of the new scheme are simulated, and the results are compared with other schemes. The research results show that, in terms of the unit rate of transmission and bandwidth demand, when N is small, DMPPM scheme is similar to that of other schemes, with the gradual increase of N, the performance of the new scheme quickly exceed the others, and has obvious advantages. The results of this study can be applied to the new optical communication modulation technology, which can achieve higher transmission rate in case of large bit number information.