Investigation of Hardware Impairments Degree Influence on the Reception Quality in Respect of the Zero-IF Receivers

In addition to the analytical approach of analyzing the analog quadrature conversion imperfections effect on the signal reception quality changing, computer simulation methods are often used in the study of complex type signals. This approach allows obtaining a visual estimation of noise immunity for real signals under the I / Q-imbalance, DC offset and phase noise influence. Quantitative evaluation of amplitude-phase imbalance and DC-offset influence level on the sensitivity decreasing and reception quality degradation has been made in the article by means of simulation. The phase noise attendance is also taking into account. Studies were carried out for M-QAM signals having indices 4 ... 256 (M-QAM). This is related to the fact of them widespread using in modern mobile, satellite and digital television systems. The researches allow defining the cases in which I/Q-imbalance and DC offset compensation is mandatory required and in which it is sufficient to use modern methods of signal coding.