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Spectrum Sensing Measurement using GNU Radio and USRP Software Radio Platform

Authors:
Rozeha A. Rashid
Mohd Adib Sarijari
Norsheila Fisal
Anthony Lo
Sh. Kamilah S. Yusof
Nurhija Mahalin

Keywords: Spectrum Sensing; Probability of Detection; Probability of False Alarm; GNU Radio; USRP

Abstract:
Spectrum utilization can be significantly improved by adopting cognitive radio (CR) technology. Such radios are able to sense the spectral environment and use this information to opportunistically provide wireless links that meet the user communications requirements optimally. To achieve the goal of cognitive radio, it is a fundamental requirement that the cognitive user (CU) performs spectrum sensing to detect the presence of the primary user (PU) signal before a spectrum is accessed as to avoid harmful interference. Therefore, two probabilities are of interest; the probability of detection, Pd and the probability of false alarm, Pfa. In this paper, we investigate sensing performance implemented on real-time testbed of GNU Radio and USRP Software Defined Radio (SDR) communication platform operating at 2.48 GHz with a bandwidth of 4 MHz. Energy detector utilizing 1024 FFT bin is the sensing mechanism used in the experimental set-up. The acquired experimental results of Pd and Pfa are duly analyzed and verified to be comparable to the curve of the theoretical framework for line-of-sight indoor environment. It is observed that at a target Pfa of 5%, the optimal decision threshold for PU detection is -39 dB. The plot of measured number of samples needed for a desired Pd for various received signal levels, representing various signal-to-noise (SNR) conditions, is also included. At SNR of 0 dB and a target Quality of Service (QoS) set at Pd of 90%, it is found out that the required sensing time for our GNU Radio USRP based CR system is equal to 31.59ms.

Pages: 237 to 242

Copyright: Copyright (c) IARIA, 2011

Publication date: June 19, 2011

Published in: conference

ISSN: 2308-4219

ISBN: 978-1-61208-140-3

Location: Luxembourg City, Luxembourg

Dates: from June 19, 2011 to June 24, 2011