Performance Limits on Ranging with Cognitive Radio

Abstract

Abstract-Cognitive radio is a promising paradigm for efficient utilization of the radio spectrum due to its capability to sense environmental conditions and adapt its communication and localization features. In this paper, the theoretical limits on time-of-arrival estimation for cognitive radio localization systems are derived in the presence of interference. In addition, an optimal spectrum allocation strategy which provides the best ranging accuracy limits is proposed. The strategy accounts for the constraints from the sensed interference level as well as from the regulatory emission mask. Numerical results are presented to illustrate the improvements that can be achieved by the proposed approach.Index Terms-Ranging, time-of-arrival (TOA) estimation, cognitive radio, interference, ultra-wideband (UWB), orthogonal frequency division multiplexing (OFDM).

Cognitive-Radio Systems for Spectrum, Location, and Environmental Awareness

“…For example, water-filling algorithms can be used to maxi mize the capacity of a communications system [71,72]. Similarly, power can be optimally distributed among available frequency components in order to improve accuracy of a ranging system [46]. Theoretical limits on range-estimation accuracy for dispersed spectrum utilization were also studied in [47].…”

“…Furthermore, in [45], a high precision ranging algorithm for dynamic-spectrum-access net works was proposed. Theoretical limits on ranging for cognitive radio localization systems in the presence of interference were studied, and an optimal spectrum-allocation strategy that provides the best ranging accuracy was proposed in [46]. The fundamental limits of time-delay estimation in dispersed-spectrum cognitive radio systems were investigated in [47].…”