Open AccessRobust beamforming and power allocation in cognitive radio relay networks with imperfect channel state information
Author(s) -
Mohammadkhani Saeideh,
Kahaei Mohammad Hossein,
Razavizadeh Seyed Mohammad
Publication year - 2014
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.2013.0601
Subject(s) - cognitive radio , beamforming , relay , computer science , channel state information , imperfect , computer network , channel (broadcasting) , relay channel , telecommunications , power (physics) , wireless , physics , quantum mechanics , linguistics , philosophy
The authors study robust beamforming and power allocation in cognitive relay networks using several relays in the secondary link. The channel state information is imperfect modelled by Gaussian random variables. First, minimisation of the total transmit power of relays and the secondary transmitter is considered with a constraint on the interference in the primary receiver. Also, a constraint is assumed on the received signal‐to‐interference plus noise ratio (SINR) in the secondary receiver. In the other scenario, maximisation of the SINR in the secondary receiver is investigated with a limit on the maximum transmit power of relays and the secondary transmitter. For each non‐convex optimisation problem, an iterative and robust algorithm is derived. It is proved that the first proposed algorithm converges to the global optimum. Simulation results similarly show the convergence of both algorithms with a few number of iterations. The outperformance of the robust algorithms is shown compared with a non‐robust design.