RSMA Precoding Design Based on Interference Nulling and Sum Rate Upper Bound

Rate splitting multiple access (RSMA), a recent generalization and merging of spatial division (SDMA) superposition coding has exponential complexity. Hierarchical streams that transmit subset possible encoded messages are proposed for rate analyzed. To reduce precoding complexity, RSMA with interference nulling (RSMA-IN), nulls the portion is not decoded investigated by formulating sum maximization problem subject to total power constraint. solve this non-convex problem, method combines stream SNR proposed. A convex upper bound formulated compare existing algorithms, conditions under which tight determined. Taking advantage cases, we propose an aided (UBA) enhancement designs exploiting optimal solutions in cases. It also shown augmented weighted mean square error (AWMSE) algorithms cannot converge local optimum maximization. Simulation results indicate approaches enhance performance over ones as well approach their bounds certain instances.