Performance Assessment of Optical Networks with CDMA

1. Performance Assessment of Optical Networks with CDMA Paulo M. Mendes DS/CDMA System Model System Operatingat 10 Gchip/s Coding Sequence (1001101) Effect of Dispersion on Eye Opening Data Sequence (1011) TC with N = 129 w = 3 C = 6 PC with N = 121 w = 11 C = 11 Coded Sequence TX Effect of Dispersion on Probability of Error PC with N = 529 w = 23 PC and OOC RX System Operatingat 20 Gchip/s APD input MGF of V(ts) Simulation Methodology Generation of the optical symbol sequence, propagation through linear fibre channel and reception with Butterworth low-pass filter; Performance estimation using the moment generating function of the output distribution with the saddle point approximation. PC with N = 529 L = 5 D = 37 Mbit/s PC with N = 121 L = 5 D = 165 Mbit/s Conclusions A new methodology for performance evaluation of optical DS/CDMA systems was developed; The prime codes are more sensitive to the fibre length than optical orthogonal codes; The dispersion tolerance depends of the relation between the code length and number of chips in the code and a longer code does not imply an improvement on dispersion tolerance; The codes to be used in DS/CDMA systems must be selected taking into consideration their dispersion tolerances; We simulated a system operating at 20 Gchip/s with a penalty < 2 dB, for L=10 km and Pe=10-9. Developed Simulator