Design And Implementation Of 2D Optical Code Division Multiple Access System Based On GTX

Optical code division multiple access(OCDMA)technology has many advantages,such as strong confidentiality,random access,soft capacity,and strong integrated services.However,the existing OCDMA system based on all-optical signal processing has some problems such as high system cost,beat noise and multiple access interference.The mature electric domain processing technology can effectively suppress multiple access interference.The mature technology of electric domain processing codec can effectively suppress multiple access interference,and the use of electric domain coding(or combined electro-optical coding)to process OCDMA systems has become a new development trend.This paper mainly studies the two-dimensional OCDMA system of electro-optic combined codec.The main content of the paper as follows:1?The principle of DSPK modulation,demodulation technology,and the classic codec technology of OCDMA system are explained.according to the principle designs DPSK-OCDMA codec solution.two users and three channels are built in Optisystem software,the rate reaches 5Gbit/s in simulation model.Based on the platform of FPGA,the verification simulation of the system is completed.The simulation results show that the DPSK-OCDMA system successfully completes the codec function and verifies the feasibility of the codec system.2?An implementation scheme of two-dimensional OCDMA codec system based on FPGA is designed.In the two-dimensional OCDMA codec system,the design function of the OCDMA codec,clock correction synchronization,frame encapsulation,decapsulation and GTX transmission modules and the system implementation scheme are elaborated in detail.Based on Xilinx Virtex-7 FPGA,the sub-modules of the system are cascaded and integrated,and a two-dimensional OCDMA system codec test is performed.The test results show that the system can correctly complete the OCDMA codec function for user signals.3?A two-dimensional OCDMA encoding and decoding system experimental scheme is designed,in which the sampling clock of three users is 250 MHz,which is converted from a low-speed parallel signal to a high-speed serial signal with a system line rate of 10Gbit/s via a GTX high-speed transceiver.A two-channel OCDMA encoding and decoding experiment with a 4-channel parallel transmission rate of 40Gbit/s,a fiber transmission distance of 10 KM was carried out,and a bit error rate test scheme for the GTX transmission channel was used.From the analysis of the experimental results,it can be known that the system can correctly decode the target for user signals,the system's 4-channel single port rate is 10Gbit/s,the bit number increment is 1.008E13 bit,and the error code is replaced by 9.916E-14,which has good performance.