Title :
Multi-antenna adaptive modulation and transmit beamforming based on bandwidth-constrained feedback
Author :
Xia, Pengfei ; Zhou, Shengli ; Giannakis, Georgios B.
Author_Institution :
Dept. of Electron. Comput. Eng., Minnesota Univ., Minneapolis, MN, USA
Abstract :
Adaptive modulation has the potential to increase system throughput considerably by matching transmission parameters to the time-varying channel conditions. Crucial to adaptive systems is the requirement of a feedback channel, that often carries only a limited number of bits. Under such a bandwidth-constrained feedback link, we aim to optimize a multi-antenna system based on transmit beamforming and adaptive modulation, where the transmit-power, the signal constellation, the beamforming direction, and the feedback strategy, are designed jointly. Our proposed nested iterative approach leads to an approximate yet practical solution. Simulation results demonstrate considerable improvement in transmission rate, as the number of feedback bits increases.
Keywords :
adaptive antenna arrays; adaptive modulation; array signal processing; bandwidth allocation; error statistics; feedback; iterative methods; optimisation; time-varying channels; BER; bandwidth-constrained feedback; bit error rate; iterative approach; multiantenna adaptive modulation; optimization; signal constellation; time-varying channel; transmit beamforming; Adaptive systems; Array signal processing; Constellation diagram; Design optimization; Feedback; Iterative methods; Optical modulation; Signal design; Throughput; Time-varying channels;
Conference_Titel :
Signals, Systems and Computers, 2004. Conference Record of the Thirty-Seventh Asilomar Conference on
Print_ISBN :
0-7803-8104-1
DOI :
10.1109/ACSSC.2003.1291894
