University of Wollongong
Browse

File(s) not publicly available

On Spectrum Sensing of OFDM Signals at Low SNR: New Detectors and Asymptotic Performance

journal contribution
posted on 2024-11-16, 04:44 authored by Ming Jin, Qinghua GuoQinghua Guo, Jiangtao XiJiangtao Xi, Youming Li, Yonghui Li
This paper deals with near-optimal spectrum sensing of orthogonal frequency division multiplexing (OFDM) signals to achieve reliable detection at low signal-to-noise ratio (SNR). The likelihood ratio test (LRT), a simple hypothesis test, delivers the optimal performance, but it requires that the parameters involved in the test are known. Hence, the generalized likelihood ratio test (GLRT), a composite hypothesis test, has often been employed. However, GLRT-based detectors involve biased parameter estimation, which may lead to inferior performance. In this paper, with proper approximation, the LRT is reduced to a simpler form, which only requires the knowledge of noise power. Then a novel unbiased and consistent estimator of the noise power is developed. This estimator is combined with the approximate LRT, leading to an asymptotic simple hypothesis test (ASHT). Two ASHT-based detectors are presented for cases with and without time synchronization, and their theoretical performances are analyzed. Simulation results show that the ASHT-based detectors deliver performances very close to that of the optimal LRT, and significantly outperform the existing GLRT-based detectors. It is also shown that the ASHT-based detectors exhibit robustness against the influence of multipath channels.

Funding

Low-complexity factor-graph-based receiver design for bandwidth-efficient communication systems over doubly selective channels

Australian Research Council

Find out more...

History

Citation

M. Jin, Q. Guo, J. Xi, Y. Li & Y. Li, "On Spectrum Sensing of OFDM Signals at Low SNR: New Detectors and Asymptotic Performance," IEEE Transactions on Signal Processing, vol. 65, (12) pp. 3218-3233, 2017.

Journal title

IEEE Transactions on Signal Processing

Volume

65

Issue

12

Pagination

3218-3233

Language

English

RIS ID

113963

Usage metrics

    Categories

    Keywords

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC