PERFORMANCE ANALYSIS OF COGNITIVE RADIO NETWORKS FOR RESOURCE SHARING

Abstract

Modern wireless applications demand the higher data rates and that led to the problem of scarcity of spectrum. According to Federal Communication Committee (FCC) 70% of statically allocated spectrums are underutilized and thus it had given legal permission for unlicensed operation for the Television White Space (TVWS). The concept of TVWS is due to the shifting of analog TV to Digital TV, traditionally reserved frequency bands in the range of 54 MHz to 698 MHz with 700 MHz band. Field surveying during this research work within the range of 0.1 MHz to 3 GHz also supports the FCC data because just about 17% of spectrum is used and apart from FM radio and Global System for Mobile (GSM) band, other licence band are almost void. In such a scenario Dynamic Spectrum Allocation (DSA) has got the higher priority and hence new concept of cognitive radio technology was emerged. Cognitive radio technology is an innovation software defined radio design that is proposed to increase the spectrum utilization by exploiting the unused spectrum with dynamically changing environment. This thesis envisions the current scenario of spectrum utilization and proposed a model for the secondary user which is not only an opportunistic user but also a co-operative user of primary user that assist for the transmission of data packet of primary user according to queuing theory. Thesis work focuses the DSA for Wireless Regional Area Network (WRAN)- IEEE 802.22, which is the first worldwide standard on cognitive radio because this offers ten times the coverage and three times better the capacity of current Wi-Fi spectrum. The hypothesis- performance is increased due to sharing of resource is became true by assuming the upper bound of 1 GB primary's data on queue and on sharing of about 50% of this data by the secondary transmitter as co-operative user is tested and found that the performance is increased by about 10% to 41% as traffic load increased upto 98%. Since, the data rate is set according to WRAN parameter as 24 Mbps, to get optimum performance of resource sharing is also achieved about 41% when traffic load is 0.98.