Torbjörn Ekman

Licentiate Thesis, Signals and Systems, Uppsala University, December 2000.

Paper copies of the thesis can be obtained from Ylva Johansson, Signals and Systems Group, Uppsala University, Box 534, SE-75121 Uppsala, Sweden.

Abstract:

Prediction of the coefficients of mobile radio channel is of interest for a range of applications such as power control, adaptive resource allocation, adaptive coding and modulation. Power control in e.g. WCDMA requires short-term prediction over only a small fraction of the distance between two dips in the short-term fading pattern. Radio resource allocation and planning would require accurate and more long-term prediction, the longer the better.

The performance of different predictors for the mobile radio channel are evaluated partly on simulated data, using a spherical wave propagation model, but mainly on measured broadband channel impulse responses from a suburban environment. The focus is mainly on adaptive and non-adaptive linear FIR predictors but quadratic-Volterra and MARS predictors are also studied.

The received power of a mobile radio channel is predicted as the sum of the squared magnitudes of the predicted individual complex taps in the channel impulse response. The linear adaptive iterated sub-sampled FIR predictor generally produces excellent predictions of both complex taps and total power for short ranges, that is up to 0.1 wavelengths. The performance of power predictors is reduced markedly at ranges over half a wavelengths. The advantage over using just the average power for prediction then becomes small, so we can not claim that the investigated predictors are efficient for these prediction ranges.

Publications:

PhD Thesis by Torbjörn Ekman, Oct. 2002.
VTC02 paper on an improved unbiased power predictor, evaluated on 39 measured channels.
RVK02 paper on using the predictor error variance for optimizing adaptive modulation.
VTC01s paper on linear prediction performance on 45 measured channels.
VTC01s paper on the analysis of the LS Estimation error on a Rayleigh fading channel.
VTC 1999 paper on quadratic and linear subsampled filters for prediction.
ICASSP 1999 paper on predictability of wideband channels, as measured by the mutual information, and on prediction using Multiple Adaptive Regression Splines.

Source:

Pdf, 2.3M