Partially Overlapping NOMA System with Many Neighboring Channels

Abstract

The increasing usage of the Internet of Things (IoT) and other modern massive machine-type communication applications has led to a growing demand for more efficient u tilization o f a vailable c ommunication bandwidth. These applications necessitate the concurrent operation of multiple communication channels. The classical approach is Orthogonal Multiple Access (OMA), such as Time Division Multiple Access (TDMA) or Frequency Division Multiple Access (FDMA). However, an emerging alternative is Non-Orthogonal Multiple Access (NOMA), where communicating parties share one or more resources. The power domain NOMA scheme employs superposition coding (SC) and successive interference cancellation (SIC) to mitigate the effects of interference caused by overlapping frequency bands. Our proposal presents a partial NOMA solution: we retain the bandwidth division from the FDMA scheme but allow for partial overlap between neighboring channels. In this approach, we do not apply SIC; instead, we treat the interference caused by the overlap as part of the noise. This scheme enables the use of a wider bandwidth for individual channels. By carefully controlling the extent of overlap, we achieve a capacity increase resulting from the wider bandwidth that outweighs the capacity loss due to increased noise.

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