الفهرس 
CHAPTER 1 : INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Cognitive radio (CR) has emerged as one of the most promising candidate solutions for improving spectrum utilization in next generation cellular networks. Spectrum sensing is a process used to detect the unused spectrum bands, holes, to enhance the utilization of scarce radio spectrum. Sampling rate is the bottleneck for spectrum sensing over multi-GHz bandwidth. Compressed sensing (CS) has been recently applied to reduce the sampling rate. In this thesis, a wideband sub-Nyquist spectrum sensing architecture based on random demodulation is designed. A Simulink model of the random demodulator-based spectrum sensing architecture is built and simulated on MATLAB to prove the system functionality. Implementation of an efficient high-speed chipping sequence for the random demodulator is presented. The proposed chipping sequence architecture can operate at 2.27 GHz clock frequency in targeted technology of 130 nm with a speedup of 13.5% compared to previously published work. Moreover, a power-optimized architecture is implemented. The main building blocks in the proposed design which are: higher speed SAR analog to digital for random demodulator analog to information converter (AIC) was designed and simulated using cadence software for performance evaluation. The design was implemented in targeted technology of 130 nm standard CMOS technology. Following comparative analyses with previously published studies, we demonstrate significant improvements in terms of speed and chip area of the SAR ADC design. The Orthogonal Matching Pursuit (OMP) which is one of the greedy iterative algorithms that are suitable for VLSI implementation is used for spectrum recovery.