Matlab modeling and analysis of the signal path in Zero-IF DVB-T/H radio receivers

This paper presents a Matlab model for the signal path within a DVB-T receiver, along with a new method for analyzing the effects various block nonidealities have on the receiver, when considering unwanted signals such as the adjacent channels and out-of-band blockers. The models for amplifier-type blocks cover not only the basic parameters - gain, bandwidth - but also the noise - though the noise factor - and the nonlinearity - through the compression and intercept points. Additional features are provided for blocks with more specific functions: gain imbalance and quadrature error are added in for the mixer model, frequency characteristics for channel filters models, quantization error for the analog-to-digital converter. The model also comprises an OFDM signal generator and the DSP block. The proposed analysis method is based on a direct, sample-by-sample, comparison between a reference signal - obtained by using a reference version of the receiver, for which some aspects are idealized - and the “real” signal, obtained by using the complete receiver model and considering all signals, wanted and unwanted.