Optical code-division multiplexing systems using Manchester coded Walsh codes

The authors propose an optical code-division multiplexing (OCDM) system using a Manchester coded Walsh code (MCWC) as the spreading code. The MCWC, which is a modification of the traditional Walsh code, has some special properties that are suitable for both single-rate and multirate synchronous OCDM systems. In such systems, the multiple-access interference (MAI) is directly proportional to the number of users; therefore, as long as the number of users is determined, the MAI can be estimated and cancelled. According to the performance analysis of the proposed system, the numerical results show that the bit error rate of the proposed OCDM system is much lower than that of other OCDM systems.