Amplitude and Phase Noise Measurement in Single Carrier Digital Modulations

Abstract

The paper deals with a new method for both the phase and the amplitude noise measurement. The method can be used for both sinusoidal signals and single carried digital modulated signals. It is based on the (i) constellation examination in the IQ plane, and (ii) the comparison of the real constellation with the ideal one. In particular, the amplitude noise is evaluated by the module excursion around the ideal symbol, and the phase noise by the angle excursion. It is shown that some advantages of the proposed method are: (i) the number of samples does not affect the measurement error, (ii) the percentage error is reduced if compared with other measurement methods, (hi) the possibility to operate directly on the modulated signal, and (iv) the phase and the amplitude noise shape weakly affects the measurement error. In order to evaluate the method performance several numerical experiments are carried out in different operative conditions