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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

This paper investigates the problem of spectrally efficient operation of amultiuser uplink cognitive radio system in the presence of a single primarylink. The secondary system applies opportunistic interference cancelation (OIC)and decode the primary signal when such an opportunity is created. We derivethe achievable rate in the secondary system when OIC is used. This scheme has apractical significance, since it enables rate adaptation without requiring anyaction from the primary system. The \emph{exact} expressions for outageprobability of the primary user are derived, when the primary system is exposedto interference from secondary users. Moreover, approximated formulas and tightlower and upper bounds for the ergodic sum-rate capacity of the secondarynetwork are found. Next, the power allocation is investigated in the secondarysystem for maximizing the sum-rate under an outage constraint at the primarysystem. We formulate the power optimization problem in various scenariosdepending on the availability of channel state information and the type ofpower constraints, and propose a set of simple solutions. Finally, theanalytical results are confirmed by simulations, indicating both the accuracyof the analysis, and the fact that the spectral-efficient, low-complexity,flexible, and high-performing cognitive radio can be designed based on theproposed schemes.

Cognitive Multiple Access Network with Outage Margin in the Primary System