The proliferation of wireless services and applications over the past decade hasudled to the rapidly increasing demand in wireless spectrum. Hence, we have beenudfacing a critical spectrum shortage problem even though several measurementsudhave indicated that most licensed radio spectrum is very underutilized. Theseudfacts have motivated the development of dynamic spectrum access (DSA) andudcognitive radio techniques to enhance the efficiency and flexibility of spectrumudutilization.udIn this dissertation, we investigate design, analysis, and optimization issues forudjoint spectrum sensing and cognitive medium access control (CMAC) protocoludengineering for cognitive radio networks (CRNs). The joint spectrum sensingudand CMAC design is considered under the interweave spectrum sharing paradigmudand different communications settings. Our research has resulted in four majorudresearch contributions, which are presented in four corresponding main chaptersudof this dissertation.udFirst, we consider the CMAC protocol design with parallel spectrum sensing forudboth single-channel and multi-channel scenarios, which is presented in Chapterud5. The considered setting captures the case where each secondary user (SU) isudequipped with multiple transceivers to perform sensing and access of spectrumudholes on several channels simultaneously.udSecond, we study the single-transceiver-based CMAC protocol engineering forudhardware-constrained CRNs, which is covered in Chapter 6. In this setting,udeach SU performs sequential sensing over the assigned channels and access oneudavailable channel for communication by using random access. We also investigateudthe channel assignment problem for SUs to maximize the network throughput.udThird, we design a distributed framework integrating our developed CMAC protocoludand cooperative sensing for multi-channel and heterogeneous CRNs, whichudis presented in details in Chapter 7. The MAC protocol is based on the p-persistentudcarrier sense multiple access (CSMA) mechanism and a general cooperativeudsensing adopting the a-out-of-b aggregation rule is employed. Moreover,udimpacts of reporting errors in the considered cooperative sensing scheme are alsoudinvestigated.udFinally, we propose an asynchronous Full–Duplex cognitive MAC (FDC-MAC)udexploiting the full-duplex (FD) capability of SUs’ radios for simultaneous spectrumudsensing and access. The research outcomes of this research are presented inudChapter 8. Our design enables to timely detect the PUs’ activity during transmissionudand adaptive reconfigure the sensing time and SUs’ transmit powers toudachieve the best performance. Therefore, the proposed FDC–MAC protocol isudmore general and flexible compared with existing FD CMAC protocols proposedudin the literature.udWe develop various analytical models for throughput performance analysis of ourudproposed CMAC protocol designs. Based on these analytical models, we developuddifferent efficient algorithms to configure the CMAC protocol including channeludallocation, sensing time, transmit power, contention window to maximize theudtotal throughput of the secondary network. Furthermore, extensive numericaludresults are presented to gain further insights and to evaluate the performance ofudour CMAC protocol designs. Both the numerical and simulation results confirmudthat our proposed CMAC protocols can achieve efficient spectrum utilization andudsignificant performance gains compared to existing and unoptimized designs.
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