Title :
Confidential broadcasting via coordinated beamforming in two-cell networks
Author :
He, Biao ; Yang, Nan ; Zhou, Xiangyun ; Yuan, Jinhong
Author_Institution :
Research School of Engineering, Australian National University, Canberra, Australia
Abstract :
We design a linear precoder based on the principles of the generalized regularized channel inversion (RCI) precoder that achieves confidential broadcasting in a two-cell network. In each cell of the network, an N-antenna base station (BS) communicates with K single-antenna users. We consider coordinated beamforming where the BSs in the two cells do not share messages but the users in the two cells feed back their channel state information to both BSs. In the precoder design, we determine the optimal regularization parameter that maximizes the secrecy sum rate. To this end, we derive new channel-independent expressions for the secrecy sum rate in the large-system regime, where K and N approach infinity with a fixed ratio μ = K/N. Moreover, we propose a power-reduction strategy that significantly improves the secrecy sum rate at high transmit signal-to-noise ratios when μ is higher than 0.5.
Keywords :
Approximation methods; Array signal processing; Broadcasting; Interference; Security; Signal to noise ratio; Transmitting antennas;
Conference_Titel :
Communications (ICC), 2015 IEEE International Conference on
Conference_Location :
London, United Kingdom
DOI :
10.1109/ICC.2015.7249505