Upper boundary of BER performance in asynchronous coherent time-spreading optical CDMA system

Abstract

Multiple-access interference (MAI) and beat noise (BN) are analyzed in asynchronous coherent time-spreading OCDMA system according to the aperiodic cross-correlation function. Relationship between the mean intensity of aperiodic crosscorrelation and MAI and BN is deduced. Considering the worst system performance, upper bound of BER performance is evaluated by the maximum value of the mean intensity of aperiodic cross-correlation. For 511 length Gold sequence, coherent time-spreading OCDMA system can support less than 5 interfering users in the worst performance.