Multiband TOA Positioning Technique Using an UHF Bandwidth Availability Model for Cognitive Radio

In this paper, the authors present a multiband time-of-arrival (TOA) positioning model and validate the performance in a practical dynamic spectrum access scenario according to results obtained from an ultra-high frequency (UHF) spectrum occupancy measurement campaign. The statistical analysis of the measured data shows a distinguishable difference between the unoccupied and occupied portion of the UHF band. The bandwidth availability for the UHF band is shown to follow a Gaussian distribution according to the measurement results. The positioning model is verified using the non-linear least squares, linear least squares and two-step maximumlikelihood location estimation algorithms. The root mean square error (RMSE) performance evaluation of the proposed model revealed the advantage of utilising five discrete bands to perform TOA estimation, especially in poor signal-to-noise ratio (SNR) conditions ranging from -10 dB to 0 dB. At a fixed SNR of 0 dB, an average RMSE improvement of 74% and 82% was observed for a double and triple band system when compared to a conventional single-band TOA system. This particular positioning technique can enable improved location estimation in a dynamic spectrum access environment.