Optimisation des filtres de mise en forme selon le rapport puissance crete a puissance moyenne

The efficiency of a power amplifier is partly determined by the peak-to-average power ratio (PAPR) of the modulated signal. Communication systems using high order quadrature amplitude modulation have large PAPR resulting in low power efficiency and high level of intermodulation distortion.;It is shown that the use of the proposed filters significantly increases the power amplifier efficiency while preserving the symbol error rate performance, 1.85 dB of output power increase is obtained. Alternatively, the filters may be used to lower the spectral emissions and improve the error probability. The results were measured on a military radio to obtain a 5 to 16 dB out of band signal power reduction.;In this thesis, we propose a simultaneous minimization of the PAPR of the transmitted signal and the intersymbol interference of the demodulated signal. This is based on the optimization of the root raised cosine filter, which is performed under spectral and power requirement constraints using multivariate optimization technique.