A new approach to parameter estimation of time-varying systems, applied to fading digital mobile radio channels
Mikael Sternad, Anders Åhlén, Lars Lindbom · 1990
Parameters of time{varying dynamic systems may sometimes be modelled as deterministic functions of time. This is shown to be feasible, and to improve the estimation accuracy, in the estimation of fading digital mobile radio channels. Such systems may be described as nite impulse responses, with coecients varying, on a short time{scale, as sinusoids. We propose to estimate the phase, amplitude and frequency of these sinusoids, in each data burst in a TDMA system. A prediction error identication algorithm has been developed, assuming each data burst to begin with a known training sequence. The parameter estimation is separated from the equalizer design and the equalization phase. The parameter estimation was tested on simulated data, generated by a two ray channel model, with 10 dB SNR. The proposed algorithm provided very accurate channel models, also in time intervals with severe fading. In contrast, the alternative approach of using recursive identication with a slidi...