OPTICAL CODE-DIVISION-MULTIPLEXED SYSTEMS BASED ON SPECTRAL ENCODING OF NONCOHERENT SOURCES

In this paper, we present a new category of optical CDMA systems which work based on spectral encoding. In such systems, that we will refer to as Frequency-Encoded CDMA (FE-CDMA) systems, the coding is done in the frequency domain while in the usual CDMA systems the code multiplies the modulation signal in the time domain. We present a new type of FE-CDMA system, based on encoding noncoherent broadband sources. We discuss the advantages of our system compared to other optical CDMA systems and present its performance. We show that very efficient low-cost, CDMA systems can be obtained with aggregate throughput of many gigabits per second. Also, for this system, the spreading gain of CDMA is independent of the modulation bandwidth. Hence, the system can accommodate variable bit rates, naturally.