roximation. diction length of about one wavelength was achieved The 2D approach showed the best results with approach whereas the narrowband approximation and the 2D ap- 2 in between, closer to the 2D than to the 1D results. proach failed. In these cases, Semmelrodt expects better Figure 4.7-48 shows the prediction results for the results when the model order of the ESPRIT estimation measured indoor data presented in the section narrow- can be made adaptive. Best performance was achieved band fading prediction, with a bandwidth of 120 MHz. with the AR-based method; in all three approaches Again, a mean-square error criterion is used, set at -20 a prediction length of about one and a half wavelength was dB. Prediction lengths with root-MUSIC were consis- achieved. The estimation errors were constant over the tently better than half a wavelength (no 2D algorithm was bandwidth and were comparable for the three approaches available for root-MUSIC). Unitary ESPRIT performed [Semm04b]. References [AJJF99] J. B. Andersen, J. Jensen, McMillan Magazines, 409: [BeSt00] O. Besson and P. Stoica. S. Jensen, and F. 316-318, Jan. 2001. Decoupled estimation of DoA Frederiksen. Prediction of [BCFF02] M. Barbiroli, C. Carciofi, and angular spread for future fading based on past G. Falciasecca, M. Frullone, a spatially distributed source. measurements. In Proc. P. Grazioso, and A. Varini. A IEEE Trans. Signal Processing, VTC1999 Fall - IEEE 51st new statistical approach for 48(7): 1872-1882, July 2000. Vehicular Technology Conf., urban environment [BHHT04a] H. Budiarto, K. Horihata, Amsterdam, The propagation modelling. IEEE K. Haneda, and J. Takada. Netherlands, Sep. 1999. Trans. Veh. Technol., 51 (5): Experimental study of non- [AIRT04] V. Algeier, A. Richter, and 1234-1241, Sep. 2002. TD- specular wave scattering R. Thomä. A gradient based 02-044. from building surface algorithm for path parameter [Berg95] J. E. Berg. A recursive roughness for the mobile tracking in channel sounding. method for street microcell propagation model