Generalized optical code construction for enhanced and Modified Double Weight like codes without mapping for SAC–OCDMA systems

• A new generalized algorithm to construct EDW and MDW like codes without mapping.
• Proposed code has maximum cross-correlation value of 1.
• A single code construction algorithm is designed for all weights greater than 2.
• Code length is independent of mapping and basic matrix as in EDW and MDW codes.
• Code is analysis for BER using balanced detection and direct detection techniques.

Double Weight (DW) code family is one of the coding schemes proposed for Spectral Amplitude Coding–Optical Code Division Multiple Access (SAC–OCDMA) systems. Modified Double Weight (MDW) code for even weights and Enhanced Double Weight (EDW) code for odd weights are two algorithms extending the use of DW code for SAC–OCDMA systems. The above mentioned codes use mapping technique to provide codes for higher number of users. A new generalized algorithm to construct EDW and MDW like codes without mapping for any weight greater than 2 is proposed. A single code construction algorithm gives same length increment, Bit Error Rate (BER) calculation and other properties for all weights greater than 2. Algorithm first constructs a generalized basic matrix which is repeated in a different way to produce the codes for all users (different from mapping). The generalized code is analysed for BER using balanced detection and direct detection techniques.