Effect of Imperfect Spectrum Sensing on the Protection of Primary User and Performance of Multi-users Environment

To fully utilize the spectrum resources, dynamic spectrum access is found to be very helpful. In this paper, a continuous time Markov chain (CTMC) based dynamic spectrum access (DSA) scheme is proposed for interaction between primary and secondary users along with the imperfect sensing environment (false alarm and misdetection). Since, collision occurs between primary and secondary users because of imperfect sensing, we derived access probability of secondary users so that primary user´s protection is ensured. Performance is simulated by varying throughput under proportional factor (PF) criterion and maximal-throughput criterion using MATLAB. Under PF criterion throughput is better but decreases sharply with increase in no. Of users.