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Multi-Level Collaborative Spectrum Sensing in Nakagami Fading Channels

Authors:
Omkalthoum El-Bashir Hamed
Mohammed Abdel-Hafez

Keywords: Spectrum sensing; opportunistic access; cognitive radio; Nakagami-m fading channel; square law combining; maximum selection combining; hard decision combining.

Abstract:
This paper is to investigate the problem of spectrum scarcity and underutilization with particular attention to the performance of opportunistic spectrum access in fading channels. In this paper we studied the energy detector in collaborative and non-collaborative sensing modes when the channels between the primary and the sensors are generalized Nakagami-m fading channel. Soft combining techniques perform well enough, but require that each spectrum sensor sends complete signal information to the band manager. Sending the signal information introduces unnecessary complexity. Moreover, it is more complicated and time consuming for the band manager to handle. To reduce the communication overhead, hard decision techniques can be used. In this paper, two techniques will be studied. The first is the simple hard decision technique, and the second is the use of multi-threshold decision technique. The results of this study show that the multi-threshold technique outperforms the single one with slight increment in the cost. The performances of all these techniques are evaluated in terms of probability of false alarm and probability of detection. Although soft decision techniques give less probability of miss detection at certain value of probability of false alarm, the hard techniques are simpler to implement. It is also found that the multi-threshold works better than the single threshold especially in low SNRs.

Pages: 284 to 289

Copyright: Copyright (c) IARIA, 2012

Publication date: June 24, 2012

Published in: conference

ISSN: 2308-4219

ISBN: 978-1-61208-203-5

Location: Venice, Italy

Dates: from June 24, 2012 to June 29, 2012