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.
|Original language||English (US)|
|Number of pages||5|
|Journal||Conference Record of the Asilomar Conference on Signals, Systems and Computers|
|State||Published - Dec 1 2003|
|Event||Conference Record of the Thirty-Seventh Asilomar Conference on Signals, Systems and Computers - Pacific Grove, CA, United States|
Duration: Nov 9 2003 → Nov 12 2003