Optimal Code Weight Selection for 2-D Optical CDMA Systems

摘要

This paper presents the detection performance of the two-dimensional optical CDMA network under varying conditions of the bit-level design parameters such as the chip length (M), the number of wavelengths in use (L), and the code weight (W). In particular, the code weight that results in the minimal BER is analytically determined as W ≈ 1.4LM/m under the assumption of sparsely distributed random code selection, where m represents the number of active nodes in the network. The derived expression is shown to closely match the optimal code weight obtained via simulation for the cases of practical interest. The BER performance using the optimal code weight when the number of active nodes is not known (and hence estimated) is also presented and compared with the optimal performance.