Open AccessJoint design of sensing and transmission in energy‐efficient cognitive radio systems over fading channels
Author(s) -
Shi Zhiping,
Chan Teh Kah,
Hung Li Kwok
Publication year - 2013
Publication title -
iet communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.355
H-Index - 62
eISSN - 1751-8636
pISSN - 1751-8628
DOI - 10.1049/iet-com.2012.0637
Subject(s) - cognitive radio , rayleigh fading , computer science , fading , transmission (telecommunications) , efficient energy use , interference (communication) , energy (signal processing) , energy consumption , channel (broadcasting) , electronic engineering , maximal ratio combining , telecommunications , algorithm , real time computing , wireless , mathematics , engineering , electrical engineering , statistics
In this study, the authors focus on energy efficiency of a cognitive radio (CR) system, in which a secondary user (SU) senses periodically and accesses opportunistically a specific band authorised to a primary user (PU). Based on a generalised expression of energy consumption, we jointly optimise sensing, transmission and frame durations to maximise the energy efficiency for a CR system and investigate the performance of the proposed design over Rayleigh fading channels. The problem of energy efficiency is formulated as a function of sensing and transmission durations with the constraints on the interference to the PU. To protect the PU, we limit the detection probability as well as restrict the interference caused by the SU because of the re‐occupancy of the PU. In a generalised model, energy consumptions of sensing, transmission and idling state need to be considered for the SU. The optimal sensing and transmission durations are obtained by a sub‐optimal iterative algorithm. The performance of energy efficiency and duration of the SU over a Rayleigh‐faded channel is investigated. Numerical results show that the proposed reduced‐complexity approach performs comparably with that of the exhaustive search algorithm.