Prior zero-forcing for relaying primary signals in cognitive network

S. H. Song, Khaled Letaief

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

7 Citations (Scopus)

Abstract

Relaying of the primary signals by cognitive base- stations (CBSs) can help the primary system and thus win CBSs a higher chance to transmit their own signals. For this purpose, conventional zero- forcing (CZF) beamforming is a straightforward solution where the primary and cognitive signals are transmitted from a multi-antenna CBS without causing interference to each other. However, with CZF, no priority is given to the primary signals, which is not consistent with the idea of cognitive radio. In this paper, we shall propose a prior ZF (PZF) method which gives priority to the primary users (PUs) by allowing the primary signals to be transmitted without considering their interference to the cognitive users (CUs), while the cognitive signals are not allowed to generate any interference to the PU. As a result, PZF provides a higher effective channel gain for the CBS-PU link and thus is preferred by the PU. The comparison of CZF and PZF with respect to the CU's performance is dictated by a tradeoff between a higher cognitive signal power (with PZF) and a lower primary interference (with CZF). It is shown that, with one CU, a target rate of 1 bit/s/Hz for the CU is the key point that differentiates the advantage of PZF and CZF, and this point is independent of the number of CBS- antennas, channel conditions, and transmit SNR.

Original languageEnglish
Title of host publication2011 IEEE Global Telecommunications Conference, GLOBECOM 2011
DOIs
Publication statusPublished - 2011
Externally publishedYes
Event54th Annual IEEE Global Telecommunications Conference: "Energizing Global Communications", GLOBECOM 2011 - Houston, TX, United States
Duration: 5 Dec 20119 Dec 2011

Other

Other54th Annual IEEE Global Telecommunications Conference: "Energizing Global Communications", GLOBECOM 2011
CountryUnited States
CityHouston, TX
Period5/12/119/12/11

Fingerprint

Base stations
Antennas
Cognitive radio
Beamforming

Keywords

  • Cognitive relaying
  • prior zero forcing
  • zero forcing

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Cite this

Song, S. H., & Letaief, K. (2011). Prior zero-forcing for relaying primary signals in cognitive network. In 2011 IEEE Global Telecommunications Conference, GLOBECOM 2011 [6134210] https://doi.org/10.1109/GLOCOM.2011.6134210

Prior zero-forcing for relaying primary signals in cognitive network. / Song, S. H.; Letaief, Khaled.

2011 IEEE Global Telecommunications Conference, GLOBECOM 2011. 2011. 6134210.

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

Song, SH & Letaief, K 2011, Prior zero-forcing for relaying primary signals in cognitive network. in 2011 IEEE Global Telecommunications Conference, GLOBECOM 2011., 6134210, 54th Annual IEEE Global Telecommunications Conference: "Energizing Global Communications", GLOBECOM 2011, Houston, TX, United States, 5/12/11. https://doi.org/10.1109/GLOCOM.2011.6134210
Song SH, Letaief K. Prior zero-forcing for relaying primary signals in cognitive network. In 2011 IEEE Global Telecommunications Conference, GLOBECOM 2011. 2011. 6134210 https://doi.org/10.1109/GLOCOM.2011.6134210
Song, S. H. ; Letaief, Khaled. / Prior zero-forcing for relaying primary signals in cognitive network. 2011 IEEE Global Telecommunications Conference, GLOBECOM 2011. 2011.
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