Reduction of peak-to-average power ratio of bandwidth efficient linear formats

The main objective of this dissertation was the development of a practical method for reducing the peak-to-average power ratio (PAPR) of bandwidth efficient Nyquist filtered linear modulation formats without impairing their spectral containment properties. The purpose of this reduction is to increase the amplifier efficiency of mobile communication handsets.; The method is an important improvement over a previously patented system that applies small amplitude adjustments to individual pulses to produce the claimed reduction. Our solution substitutes a computationally expensive algorithm with a look-up table or an artificial neural network computed off-line, without losing any PAPR reduction performance for presently used modulation formats. These claims were confirmed by extensive computer simulations.; In addition, since the original method was a solution ad-hoc for a specific optimization problem, the use of general optimization tools to solve the PAPR reduction was also studied. Computer simulations showed little improvement in PAPR reduction performance when using the general optimization tool.; Finally, an experimental setup to measure the real effect of the amplitude adjustment method on the efficiency and spectral regrowth of real linear power amplifiers was designed, constructed and tested. Measurement results indicated that the real improvement on the efficiency performance of mobile handset amplifiers is much less than anticipated by theory.