Scalable Channel Allocation in Downlink NOMA Using Parallel Array of Laser Chaos Decision-Maker

Non-orthogonal multiple access (NOMA) is a technology that multiplexes multiple users on the same channel at transmitters through appropriate channel allocation, and the signal detection of multiple users at receivers is conducted based on successive interference cancellation. Real-time processing requires an ultra-fast channel allocation scheme. Previous studies have demonstrated that a laser chaos decision-maker is ultra-fast and effective in solving the decision-making problem. This study demonstrates a scalable channel allocation using a laser chaos decision-maker. The possible approaches to channel allocation increase abruptly with the number of users, which is difficult to handle with the previously proposed NOMA principle using a single laser chaos decision-maker in which its decision corresponds to the channel allocation for all users. Here, the proposed principle adopts an array of laser chaos decision-makers, each of which decides a channel for a particular user. Using this architecture, the proposed scheme can handle an increasing number of users or realize a scalable and ultrafast channel allocation in NOMA. The obtained numerical results indicate that the proposed approach obtains a higher throughput than conventional-NOMA and uniformed channel gain difference-NOMA in several wireless communication environments with differences in density and distance decay.