Title :
Throughput maximization for the multiuser MIMO broadcast channel
Author :
Boche, Holger ; Schubert, Martin ; Jorswieck, Eduard A.
Author_Institution :
Heinrich-Hertz-Inst. fur Nachrichtentech. Berlin GmbH, Germany
Abstract :
We consider the problem of maximizing the throughput (sum rate) of the Gaussian MIMO broadcast channel under a sum power constraint. Assuming that decision feedback precoding is used at the transmitter, this is a concave optimization problem. A computationally efficient algorithm has been proposed (Jorswieck, E. and Boche, H., WPMC, 2002), which successively performs iterative waterfilling and power control. This strategy is based on uplink/downlink duality. We expand those results, by providing necessary and sufficient conditions for when this dedicated strategy achieves the optimal sum capacity. For the low SNR regime, it is shown that the capacity achieving strategy is single user transmission over the channel with the largest maximal eigenvalue. Furthermore, we illustrate, by numerical simulations, the properties of the sum capacity without precoding.
Keywords :
Gaussian channels; MIMO systems; automatic repeat request; broadcast channels; channel capacity; covariance matrices; duality (mathematics); eigenvalues and eigenfunctions; iterative methods; multi-access systems; multiuser channels; optimisation; power control; Gaussian channel; SNR; channel capacity; channel covariance matrix; concave optimization problem; decision feedback precoding; iterative waterfilling; maximal eigenvalue; multiple access channel; multiuser MIMO broadcast channel; multiuser channel; optimal sum capacity; power control; sum power constraint; throughput maximization; uplink/downlink duality; Broadcasting; Downlink; Eigenvalues and eigenfunctions; Feedback; Iterative algorithms; MIMO; Power control; Sufficient conditions; Throughput; Transmitters;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03). 2003 IEEE International Conference on
Print_ISBN :
0-7803-7663-3
DOI :
10.1109/ICASSP.2003.1202766