Modeling of time domain represented signals with multitone signals

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: GÖKHAN CANSIZ

Danışman: ŞİMŞEK DEMİR

Özet:

Signals in certain systems, such as the transmitted signal in a cellular communication system, are strongly time dependent, non-deterministic and stochastically not well defined. Predicting the performance of the transmitter with such a signal at its input is important for efficient operation. Therefore, it is crucial to model a given time dependent waveform by multi-tone signals, which enables analytical derivations. In this thesis, multi-tone representation is employed to model the varying envelope arbitrary waveforms. Number, amplitude, phase of the tones and spacing between tones are considered as parameters for the multi-tone stimuli. To prove the validity of the multi-tone representation, CCDF curve is considered as a figure of merit for comparison. Different nonlinear amplifiers are excited with an arbitrary waveform and its multi-tone representation in the simulation environment. At the output of the amplifier, similar nonlinear behaviors such as, in-band and out of band distortion powers are observed. After proving that original and model signal have similar nonlinear responses, modulation performance of the arbitrary waveform and model signal in a transmitter chain is investigated for different drive levels.