Direct-detection optical CDMA receiver with interference estimation and double optical hardlimiters

摘要

This paper proposes a new channel interference cancellation technique using interference estimation and double optical hardlimiters (DHL) for direct-detection optical code-division multiple-access (CDMA) systems. In the proposed system, when the output of the DHL is "0", the proposed system outputs "0". When the output of the DHL is "1", the proposed system reconstructs the interference and estimates whether the output "1" is owing to the interference or the transmitted signal. From the theoretical analysis and computer simulations, we show that the proposed system is effective to reduce the effect of the channel interference and improve the BER performance of optical CDMA systems.