On the Performance Evaluations of Uplink Cognitive Femtocell SCMA Systems Under Imperfect Channel Sensing

In this paper, we investigate the performance of a femtocell implementing sparse code multiple access (SCMA) system, which has the ability to access the wireless channel opportunistically using cognitive radio (CR) capabilities. Dynamic spectrum access (DSA) of CR enable the femtocell to works on the channels with the lowest level of interferences. The interference level of a channel which is indicated by an interference signature determine the channel usage priority level. Simulation result show degradation of bit error rate (BER) when probability of missed detection of energy detection spectrum sensing increase. It is also shown that as the decision threshold of energy detection become higher, the number of received bit error in the femtocell base station increased.