Energy-Efficient MISO Systems Using Adaptive Modulation and Coding

By viewing the coherent wireless sensor network (WSN) setup as a distributed space-time multi-input single-output (MISO) system, we minimize average transmit-power when sensors communicate with a fusion center (FC) using adaptive modulation and coding over a wireless fading channel. To this end, we derive optimal distributed beamforming and resource allocation strategies when the full (F-) channel state information at the transmitters (CSIT) is available, or, each sensor has F-CSIT of its own link with the FC but only quantized CSIT of other sensors through finite-rate feedback. Numerical results are presented to evaluate the power savings of the novel strategies.