Filtering for Uplink Non-Orthogonal Multiple Access with Imperfect Received Power Control

In this work, we propose a low-complexity enhancement for uplink non-orthogonal multiple access (NOMA). The proposed scheme, called Filtered NOMA (F-NOMA) aims to improve the error performance for scenarios in which the received user powers cannot be controlled perfectly at the receiver. The proposed scheme benefits from the uniqueness of the frequency spectrums of the superimposed signals to detect the signals of multiplexed users at the receiver. We demonstrate that the proposed scheme improves the error performance of uplink power-domain NOMA significantly and increases the number of supported users. We also show that the scheme also brings an improvement in the error performance of other uplink NOMA methods, which already benefit from different types of user specific signatures.