Power Amplifier Switching (PAS) for Energy Efficient Systems

Abstract—We propose a power amplifier (PA) switch-ing/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. This letter is the first study to investigate and verify the potential capability of PAS for the system EE improvement in wireless communications. Index Terms—Energy efficiency, power amplifier bank, power amplifier switching, power amplifier selection. I