Rate Comparison of Two-User Network Applying Various Multiple-Access Techniques

In multi-user wireless cellular networks, transmission of information can be on orthogonal basis or non-orthogonal basis. Both types of medium access has advantages and disadvantages. The main challenge of orthogonal methods is the inefficient utilization of the spectrum while non-orthogonal methods are challenged by interference. Effect of interference in non-orthogonal multiple access (NOMA) methods can be reduced if some of users apply successive interference cancellation (SIC). In this work we consider the two-user case and investigate the rate performance assuming non-fading regime. The aim is to identify use cases where orthogonal multiple access (OMA) outperform NOMA and vice versa. We also consider various cases for applying SIC in NOMA. We relied on analytical methods, and to lesser extent on simulation, to come with some conclusions about rate performance. Although the assumed model is simple, it gives useful insight to understanding these two types of multiple access and related trade-offs. The assumed model is also important in acting as the base model used for conducting further studies.