A novel low complexity differential energy detection for sensing OFDM sources in low SNR environment

Abstract

Abstract-This paper presents a novel frequency-domain energy detection scheme based on extreme statistics for robust sensing of OFDM sources in the low SNR region. The basic idea is to exploit the frequency diversity gain inherited by frequency selective channels with the aid of extreme statistics of the differential energy spectral density (ESD). Thanks to the differential stage the proposed spectrum sensing is robust to noise uncertainty problem. The low computational complexity requirement of the proposed technique makes it suitable for even machine-to-machine sensing. Analytical performance analysis is performed in terms of two classical metrics, i.e. probability of detection and probability of false alarm. The computer simulations carried out further show that the proposed scheme outperforms energy detection and second order cyclostationarity based approach for up to 10 dB gain in the low SNR range.

Maximum - Minimum Energy Based Spectrum Sensing under Frequency Selectivity for Cognitive Radios

“…• A conceptually and computationally simplified sensing method based on subband energy differences (called Max-Min ED) is developed. • Max-Min ED and the differential method from [14] are evaluated and compared in two different sensing scenarios: (i) non-oversampled case, where the subband energy differences are due to the frequency selective channel only, and (ii) oversampled case, where the spectral variability is due to both multipath channel and the transmitted spectral shape. The remainder of the paper is organized as follows: Section II formulates first the system model and the basic ED scheme and then presents two sensing methods which are based on the variation of the subband energies.…”

“…The remainder of the paper is organized as follows: Section II formulates first the system model and the basic ED scheme and then presents two sensing methods which are based on the variation of the subband energies. First the differential maximum-minimum energy based method from [14] is described. Then a conceptually simpler scheme, utilizing just the difference of maximum and minimum subband energies, is described.…”