Spectral-amplitude-encoding optical-code-division-multiplexing system with a heterodyne detection receiver for broadband optical multiple-access networks

Feature Issue on Optical Access Networks (OAN) We propose a spectral-amplitude-encoding optical-code-division-multiplexing (SAE∕OCDM) system with a heterodyne detection receiver for broadband optical multiple-access networks (OMANs). The performance of the proposed system is theoretically analyzed, taking into account various types of noise and interference, including multiple-access interference (MAI), cross talk, optical beating interference (OBI), and receiver noise. Analytical results show that the proposed system offers significant improvement in terms of receiver sensitivity and system capacity (number of users) compared with conventional direct-detection systems. We also discuss conditions necessary for a heterodyne detection receiver to work properly in a SAE∕OCDM system. In addition, the system performance is analyzed with several signature code sets including m-sequence, Hadamard, and modified quadratic congruence (MQC) code sets. It is found that signature code sets with higher weight, such as m-sequence and Hadamard code sets, are preferred in a SAE∕OCDM system with a heterodyne detection receiver.