Performance Analysis of Hybrid 2D Codes at Constant Weight Using (n, w, λa, λc) OOCs for OCDMA

详细

Hybrid optical two-dimensional (2D) codes due to their large cardinality and improved system performance for constant weight have recently been designed and studied for optical CDMA system. In this manuscript, an attempt has been made to analyze the performance of four different 2D codes from a communication point of view; that describe their use to support a system under certain conditions. These hybrid 2D codes employ (n, w, λ_a, λ_c) optical orthogonal coding for one dimension that is for time spreading and synchronized prime sequences (SPS), synchronized quadratic congruence sequences (SQC), prime code sequences (PC), and synchronized prime procession (SPP) for other dimension that is for wavelength hopping respectively. The distinguishing property amongst the four codes lies in their values of maximum auto- and cross- correlation function. It has been observed that with the constant value of weight, the code with the largest code length parameter has shown the best performance while the code with the least code length gives the poorest performance. Investigations reveal that SPS/OOC code performs better in comparison to other codes with constant weight and for different number of wavelengths and SQC/OOC results in poor performance due to lesser code length.