Introduction

The invention is an algorithm that allows to find the optimum power allocation vector for non orthogonal multiple access (NOMA) transmission applied to 5G and 6G wireless communication systems. The algorithm addresses the cases of complete or limited successive interference cancellation to adapt to the receiver processing power.

Technical features

Non orthogonal multiple access (NOMA) has been proposed as a key transmission technique for both 5G and 6G wireless systems. NOMA can be applied to both the downlink multiuser brodcast channel and to the uplink multiple access channel. The former requires superposition encoding. In both cases, successive interference cancellation (SIC) is applied at the receiver. Optimum performance according to a proportional fairness criterion is attained by optimizing the power allocation coefficients used for superposition encoding over the downlink or to fix the user transmission powers over the uplink. The invention is a fast, numerically stable algorithm to derive the optimum power allocation coefficients, which addresses the cases of complete or limited successive interference cancellation to adapt to the receiver processing power (which is very important for hand-held terminals). Current research activities have considered many aspects of PD-NOMA (Power-domain NOMA) but there are no references addressing simultaneously the case of a large number of users, flexible fairness definition, and limited complexity of the terminals. TRL: 2

Possible Applications

• Uplink and downlink multiuser communications over wireless terrestrial systems;
• Uplink and downlink multiuser communications over satellite systems;
• Multiuser communications over optical networks.

Advantages

• Solving of NOMA power allocation optimization under fairness criterion;
• Fast and numerically stable algorithm;
• Limited number of interference cancellation steps reducing the complexity of portable terminals with many users.