English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

In this paper, detection of the primary user (PU) signal in an orthogonalfrequency division multiplexing (OFDM) based cognitive radio (CR) system isaddressed. According to the prior knowledge of the PU signal known to thedetector, three detection algorithms based on the Neyman-Pearson philosophy areproposed. In the first case, a Gaussian PU signal with completely knownprobability density function (PDF) except for its received power is considered.The frequency band that the PU signal resides is also assumed known. Detectionis performed individually at each OFDM sub-carrier possibly interfered by thePU signal, and the results are then combined to form a final decision. In thesecond case, the sub-carriers that the PU signal resides are known.Observations from all possibly interfered sub-carriers are considered jointlyto exploit the fact that the presence of a PU signal interferers all of themsimultaneously. In the last case, it is assumed no PU signal prior knowledge isavailable. The detection is involved with a search of the interfered band. Theproposed detector is able to detect an abrupt power change when tracing alongthe frequency axis.

Spectrum Sensing in Wideband OFDM Cognitive Radios