Detection of unknown constant magnitude signals in time-varying channels

Daniel Romero, Roberto López-Valcarce

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations

Abstract

Spectrum sensing constitutes a key ingredient in many cognitive radio paradigms in order to detect and protect primary transmissions. Most sensing schemes in the literature assume a time-invariant channel. However, when operating in low Signal-to-Noise Ratio (SNR) conditions, observation times are necessarily long and may become larger than the coherence time of the channel. In this paper the problem of detecting an unknown constant-magnitude waveform in frequency-flat time-varying channels with noise background of unknown variance is considered. The channel is modeled using a basis expansion model (BEM) with random coefficients. Adopting a generalized likelihood ratio (GLR) approach in order to deal with nuisance parameters, a non-convex optimization problem results. We discuss different possibilities to circumvent this problem, including several low complexity approximations to the GLR test as well as an efficient fixed-point iterative method to obtain the true GLR statistic. The approximations exhibit a performance ceiling in terms of probability of detection as the SNR increases, whereas the true GLR test does not. Thus, the proposed fixed-point iteration constitutes the preferred choice in applications requiring a high probability of detection.

Original languageEnglish (US)
Title of host publication2012 3rd International Workshop on Cognitive Information Processing, CIP 2012
DOIs
StatePublished - Aug 13 2012
Event2012 3rd International Workshop on Cognitive Information Processing, CIP 2012 - Baiona, Spain
Duration: May 28 2012May 30 2012

Publication series

Name2012 3rd International Workshop on Cognitive Information Processing, CIP 2012

Other

Other2012 3rd International Workshop on Cognitive Information Processing, CIP 2012
CountrySpain
CityBaiona
Period5/28/125/30/12

Fingerprint Dive into the research topics of 'Detection of unknown constant magnitude signals in time-varying channels'. Together they form a unique fingerprint.

  • Cite this

    Romero, D., & López-Valcarce, R. (2012). Detection of unknown constant magnitude signals in time-varying channels. In 2012 3rd International Workshop on Cognitive Information Processing, CIP 2012 [6232933] (2012 3rd International Workshop on Cognitive Information Processing, CIP 2012). https://doi.org/10.1109/CIP.2012.6232933