Spectrally-Temporally Adapted Spectrally Modulated Spectrally Encoded (SMSE) Waveform Design for Coexistent CR-Based SDR Applications

This work expands the applicability of the Spectrally Modulated, Spectrally Encoded (SMSE) framework by developing a waveform optimization process that enables intelligent waveform design. The resultant waveforms are capable of adapting to a spectrally diverse transmission channel while meeting coexistent constraints. SMSE waveform design is investigated with respect to two different forms of coexisting signal constraints, including those based on resultant interference levels and those based on resultant power spectrum shape. As demonstrated, the SMSE framework is well-suited for waveform optimization given its ability to allow independent design of spectral parameters. This utility is greatly enhanced when soft decision selection and dynamic assignment of SMSE design parameters are incorporated. Results show that by exploiting statistical knowledge of primary user spectral and temporal behavior, the inherent flexibility of the SMSE framework is effectively leveraged such that SMSE throughput (Bits/Sec) is maximized while limiting mutual coexistent interference to manageable levels

COOPERATIVE SPECTRUM ACCESS FOR DECENTRALIZED COGNITIVE RADIO SYSTEM

Cognitive radio (CR) is a promising technology available to that seeks the range and efficiency of spectrum dependent services. Its system maps unused spectrum, and arrange secondary user (SU) to operate within unoccupied license spectrum. The implementation of CR system guarantees that there are no interferences to primary user (PU) by prior observing and sensing the existing spectrum environment. Spectrum sensing is the main issue ofCR system to prevent the harmful interference to PU as a license user. However, practically detection performance is often compromised with multipath fading, shadowing and uncertainty noises. In order to minimize the impact of these issues, cooperative spectrum sensing and access is an effective method to improve detection performance