  The proliferation of wireless services and applications over the past decade
has led to the rapidly increasing demand in wireless spectrum. Hence, we have
been facing a critical spectrum shortage problem even though several
measurements have indicated that most licensed radio spectrum is very
underutilized. These facts have motivated the development of dynamic spectrum
access (DSA) and cognitive radio techniques to enhance the efficiency and
flexibility of spectrum utilization.
  In this dissertation, we investigate design, analysis, and optimization
issues for joint spectrum sensing and cognitive medium access control (CMAC)
protocol engineering for cognitive radio networks (CRNs). The joint spectrum
sensing and CMAC design is considered under the interweave spectrum sharing
paradigm and different communications settings. Our research has resulted in
four major research contributions, namely, the CMAC protocol design with
parallel spectrum sensing, the CMAC protocol with sequential sensing, the CMAC
protocol with cooperative sensing and the asynchronous Full-Duplex cognitive
MAC.
  We develop various analytical models for throughput performance analysis of
our proposed CMAC protocol designs. Based on these analytical models, we
develop different efficient algorithms to configure the CMAC protocol including
channel allocation, sensing time, transmit power, contention window to maximize
the total throughput of the secondary network. Furthermore, extensive numerical
results are presented to gain further insights and to evaluate the performance
of our CMAC protocol designs. Both the numerical and simulation results confirm
that our proposed CMAC protocols can achieve efficient spectrum utilization and
significant performance gains compared to existing and unoptimized designs.
