High precision concatenated spectrum cognitive radio-based range estimation

Fundamentally, high precision RF range measurement requires the availability of high bandwidth signal. This paper proposes high precision active range estimation in wireless environments by concatenating the available white spaces in spectrum. These white spaces are identified and allocated by the capabilities of cognitive radios (CR). Cognitive Radios allow efficient and flexible usage of the radio spectrum because they can sense environmental conditions and adapt their communication features. In this work, multiple bands are concatenated by active sensors that contribute in the process of ranging to attain an accuracy corresponding to the equivalent full band. Active sensors communicate with base station (BS) to allow the BS to estimate their distance. Two scenarios are investigated: the message signal is transmitted over these bands either simultaneously (parallel concatenation) or sequentially (serial concatenation). Both proposed approaches relax design requirements of both analog and digital components of our system. This work investigates the potential of different high resolution TOA estimation methods such as MUSIC for multi-band scenarios. Simulation results confirm that the proposed multi-band system leads to better ranging performance in term of the variance-of-error comparing to the average of estimated range over each sub-band.