The effect of power control on the average power amplifier efficiency

We present a study on the effect of power control algorithms on the average efficiency of a power amplifier (PA). The efficiencies are analytically calculated. Several efficiency curves of PAs are considered. The power control algorithms are the water-filling algorithm and the full and truncated channel inversion algorithms. The algorithms have an ideal knowledge of the power gain of the channel. Constant amplitude and also Gaussian distributed data signals simulating orthogonal frequency division multiplexing (OFDM) are used. Several channel models are considered. The analysis is verified via Monte Carlo simulations. We obtain realistic average power amplifier efficiency performance that takes into account the power control algorithm as well as the input signal power distribution, for various types of channels and signals. The study shows that the power control should be reckoned with when investigating the average power amplifier efficiency. Using power control improves the PA average efficiency. The higher the cut-off value, the higher the PA average efficiency, at the expense of the throughput.

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