Cognitive OFDM-NOMA System: A succinct Study

Abstract

Abstract Integration of non-orthogonal and orthogonal multiplexing used to enhance the capacity of the system is presented here. This is also called as cognitive OFDM- NOMA. Here we overcome some problems which are divided into sub problems i.e., the power allocation optimization, user scheduling and sensing duration, respectively. Orthogonal frequency division multiplexing (OFDM) for multiusers can also be done by clustering based radio allocation (RA) scheme. This will improve maximum usage of wireless communications by optimizing the sum capacity of secondary users. The users in same group have the same OFDM sub channels to enhance spectrum utilization. Mobile networks have used time/frequency/code domain for multiple access, while in NOMA the power domain will be used.