Technology Research Of Optical CDMA Spread Spectrum Coding In Space

Optical code division multiple access in space (OCDMA) is a communication mode which introducesthe code-division multiple access (CDMA) technology into wireless optical communication system. Basing on the principle of spread spectrum, this article has made the simulation to the existing wireless OCDMA address codes and carried out the construction of wireless OCDMA multi-dimensional codes with large capacity around the study of multiple freedom degrees of optical encoding mechanism to fulfil the demand of the large capacity and good correlation to the OCDMA in space.Basing on the study of the channel model of the wireless optical in space and considering the ideal free space channel and the additive white Gaussian noise channel,this article has investigated the channel capacity,discussed the frequency efficiency,and proved the feasibility of multiple freedom degrees encording from the angle of information theory.