Modeling of time domain represented signals with multitone signals

Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Electrical and Electronics Engineering, Turkey

Approval Date: 2014


Supervisor: ŞİMŞEK DEMİR


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.