Accurate information regarding a cognitive radio user's location and environment can enhance the adaptive and spectral awareness capabilities of cognitive radio systems. In this paper, a single-path multiband Time-of-Arrival (TOA) positioning technique for cognitive radio is proposed and the performance evaluated using maximum-likelihood (ML) location estimation for a typical rural scenario where signal line-of-sight (LOS) between a transmitter and receiver is prevalent. The multiband Cramer Rao Lower Bound (CRLB) time-delay and channel fading coefficient estimates are derived followed by an estimation combining technique which involves selecting an overall optimum estimate using all the utilized bands. It is observed that the improvement in positioning accuracy for the multiband system depends primarily on the number of utilized bands as well as the (signal-to-noise ratio) SNR of these bands.
Presented is an efficient bandwidth determination model for the Cognitive Positioning System by utilising multiple receive antennas. The performance evaluations of the proposed multiple receive antenna positioning system were carried out using the linear least squares and maximum-likelihood location estimation techniques. The simulated results reveal that in a rural scenario, the 1×2 and 1×3 single-input-multiple-output (SIMO) cases display an average bandwidth efficiency with respect to positional accuracy, of 49% and 58% respectively, over the single-input-single-output (SISO) case. For an urban scenario, the 1×2 and 1×3 SIMO cases display a higher average bandwidth efficiency of 53% and 62% respectively over the SISO case.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.