Power Amplifier Switching (PAS) for Energy Efficient Systems
The authors propose a Power Amplifier (PA) Switching/Selection (PAS) method to improve the Energy Efficiency (EE) of a Transmit Antenna Selection and Maximum Ratio Combining (TAS-MRC) system. A PAS transmitter has a PA bank consisting of multiple dissimilar PAs, which operate with different output power levels, and selects the most efficient PA and its power level that satisfies a target rate. If there is no PA supporting the target rate, the transmitter is set to an off-mode (i.e., all PAs are turned off). The receiver feeds back the choice of PA and its power level to the transmitter, similar to the feedback in a conventional power control system with a single PA. Numerical results show that the system EE can be improved by using the PAS.