Optical OPPM-CDMA receivers with chip-level detectors

A chip-level detector for optical overlapping pulse-position modulation code-division multiple-access (OPPM-CDMA) communication systems is proposed. The bit error rate of the proposed system is derived and compared to some traditional receivers under the constraints of fixed data rate and laser pulsewidth. These traditional receivers include OOK-, PPM- and OPPM-CDMA correlators. The throughput limitations of all these receivers are also presented and compared. The results reveal that a significant improvement in the performance is gained when using the proposed scheme. The throughput limitation of the OPPM-CDMA chip-level detection scheme is greater than that of an on-off keying CDMA correlation detection scheme by 7.5 times on average, when the bit error rate does not exceed 10^-9