TY - GEN
T1 - Broadcasting with channel state information
AU - Sidiropoulos, Nikolaos
AU - Davidson, T. N.
PY - 2004/12/1
Y1 - 2004/12/1
N2 - We consider the problem of transmit downlink beamforming for wireless transmission in the context of certain broadcasting or multicasting applications wherein Channel State Information (CSI) is available at the transmitter, and a common message is to be transmitted to the users. Unlike the usual "blind" isotropic broadcasting scenario, the availability of CSI allows transmit optimization. We adopt a minimum transmission power criterion, subject to prescribed minimum received Signal-to-Noise Ratio (SNR) at each of the intended receivers. We also consider a related max-min SNR "fair" problem formulation subject to a transmit power constraint. The basic problem is non-convex and thus difficult to solve; however, we show that a suitable reformulation allows the application of semidefinite relaxation (SDR) techniques. SDR yields a (generally approximate) solution, but in many cases our solution is optimal, and in most cases it is within 3-4 dB from the optimal solution, which is often good enough in our intended applications. While the focus of the paper is on a wireless communication scenario, we also discuss related problems in downstream preceding for broadcasting in digital subscriber line systems.
AB - We consider the problem of transmit downlink beamforming for wireless transmission in the context of certain broadcasting or multicasting applications wherein Channel State Information (CSI) is available at the transmitter, and a common message is to be transmitted to the users. Unlike the usual "blind" isotropic broadcasting scenario, the availability of CSI allows transmit optimization. We adopt a minimum transmission power criterion, subject to prescribed minimum received Signal-to-Noise Ratio (SNR) at each of the intended receivers. We also consider a related max-min SNR "fair" problem formulation subject to a transmit power constraint. The basic problem is non-convex and thus difficult to solve; however, we show that a suitable reformulation allows the application of semidefinite relaxation (SDR) techniques. SDR yields a (generally approximate) solution, but in many cases our solution is optimal, and in most cases it is within 3-4 dB from the optimal solution, which is often good enough in our intended applications. While the focus of the paper is on a wireless communication scenario, we also discuss related problems in downstream preceding for broadcasting in digital subscriber line systems.
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M3 - Conference contribution
AN - SCOPUS:28244457859
SN - 0780385454
T3 - 2004 Sensor Array and Multichannel Signal Processing Workshop
SP - 489
EP - 493
BT - 2004 Sensor Array and Multichannel Signal Processing Workshop
T2 - 2004 Sensor Array and Multichannel Signal Processing Workshop
Y2 - 18 July 2004 through 21 July 2004
ER -