Skip to main content

Table 2 Qualitative comparison of the complexity of different strategies

From: Rate-splitting multiple access for downlink communication systems: bridging, generalizing, and outperforming SDMA and NOMA

Multiple access NOMA SDMA RSMA
Strategy SC–SIC SC–SIC per group MU–LP RS 1-layer RS
Encoder complexity Encode K streams Encode K streams Encode K streams Encode K private streams plus additional common streams Encode K+1 streams
Scheduler complexity Very complex as it requires to find aligned users and decide upon suitable user ordering Very complex as it requires to divide users into orthogonal groups, with aligned users in each group and decide upon suitable user ordering in each group Complex as MU–LP requires to pair together semi-orthogonal users with similar channel gains Complex as it requires to decide upon suitable decoding order of the streams with the same stream order Simpler user scheduling as RS copes with any user deployment scenario, does not rely on user grouping and user ordering
Receiver complexity Requires multiple layers of SIC. Subject to error propagation Requires multiple layers of SIC in each group and a single layer of SIC if groups are made of 2 users. Subject to error propagation Does not require any SIC Requires multiple layers of SIC. Subject to error propagatio Requires a single layer of SIC for all users. Less subject to error propagation