Multi-class optical-CDMA network using optical power control

In this paper we use optical power control to support multirate transmission over temporal optical CDMA networks. We apply the centralized power control algorithm to set the transmit power of the users' optical sources in order to satisfy a given target QoS. In addition, optical amplifiers are included to enhance the overall system performance while the Amplified Spontaneous Emission (ASE) is considered as the main noise source. The objective function defined as the sum of the transmitted optical power from all nodes is minimized subject to a signal-to-interference (SIR) constraint. Moreover, the network feasibility, defined as the ability to evaluate a power vector that satisfy the target SIR, is discussed in terms of the spectral radius of the network interference matrix. Next, the spectral radius of the network interference matrix is investigated and modeled as a truncated Gaussian distribution. Last, a rate reduction algorithm, categorized in terms of the number of nodes involved in the process of rate reduction, is proposed to increase the network feasibility. As more nodes are added to the rate reduction campaign, the network feasibility is significantly enhanced. For typical network parameters we find by simulating 10⁴ random network realizations that a three-node rate reduction results in 99% network feasibility.