Demonstration of Uncoordinated Multiple Access in Optical Communications

Though it promises high bandwidths, the optical medium is not popular in local area networks. This is because current optical networks do not offer the ease of use and setup that an uncoordinated multiple access network such as Ethernet offers. In this paper, we propose a novel nonlinear trellis code designed for multiple access among uncoordinated nodes in an optical communications system. This code has been shown to have an efficiency of 30%. We have implemented the codes on Xilinx FPGA's for a 6 user optical system, transmitting data on a single wavelength. The above system was set up using commercial off-the-shelf components and we demonstrated BER -9 of for three users, each running at a channel rate of 2 Gbps. Demonstration of this system required the design of new channel codes, architectural optimizations for the implementation of the channel codes for high speed with limited resources and electrical/optical optimizations to realize the optical channel.