Distributed coordinated beamforming for multi-cell multigroup multicast systems
English
Pennanen, Harri[University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT) > >]
Christopoulos, Dimitrios[University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT) > >]
Chatzinotas, Symeon[University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT) > >]
Ottersten, Björn[University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT) > >]
Jul-2016
Communications (ICC), 2016 IEEE International Conference on
IEEE
Yes
International
978-1-4799-6664-6
Communications (ICC), 2016 IEEE International Conference on
from 23-05-2016 to 27-05-2016
Kuala Lumpur
Malaysia
[en] Array signal processing ; Interference ; Signal to noise ratio ; Optimization ; Multicast communication ; Minimization ; Wireless communication
[en] This paper considers coordinated multicast beam-forming in a multi-cell wireless network. Each multiantenna base station (BS) serves multiple groups of single antenna users by generating a single beam with common data per group. The aim is to minimize the sum power of BSs while satisfying user-specific SINR targets. We propose centralized and distributed multicast beamforming algorithms for multi-cell multigroup systems. The NP-hard multicast problem is tackled by approximating it as a convex problem using the standard semidefinite relaxation method. The resulting semidefinite program (SDP) can be solved via centralized processing if global channel knowledge is available. To allow a distributed implementation, the primal decomposition method is used to turn the SDP into two optimization levels. The higher level is in charge of optimizing inter-cell interference while the lower level optimizes beamformers for given inter-cell interference constraints. The distributed algorithm requires local channel knowledge at each BS and scalar information exchange between BSs. If the solution has unit rank, it is optimal for the original problem. Otherwise, the Gaussian randomization method is used to find a feasible solution. The superiority of the proposed algorithms over conventional schemes is demonstrated via numerical evaluation.