Extension of the ITU Channel Models for Wideband Frequency dependant Systems

The ITU power delay profiles (PDP) defined by the recommendations of the ITU are well-established channel models for research of mobile communication systems. They specify channel conditions for various operating environments encountered in third-generation wireless systems. These systems operate in a 5 MHz bandwidth and are based on WCDMA principles. In this project we developed a simple procedure to extend, or upsample, the ITU profiles to improve the frequency correlation properties while keeping the same mean delay and almost the same rms delay spread. Realistic frequency correlation properties are of particular importance for the evaluation of wideband system concepts with frequency dependent characteristics, e.g. frequency domain link adaptation and packet scheduling, both of which are likely to be part of an OFDM-based system. With the suggested procedure the frequency correlation can be kept approximately at or below 0.6 for frequency separations up to 25 MHz for the exemplified ITU Vehicular A and Pedestrian B channel profiles. (Troels B. Sørensen, Preben E. Mogensen & Frank Frederiksen, Nokia Networks)