The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.
Aalto

On the Modeling of WCDMA System Performance with Propagation Data

Kari Heiska

Dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the Department of Electrical and Communications Engineering for public examination and debate in Auditorium S4 at Helsinki University of Technology (Espoo, Finland) on the 23rd of April, 2004, at 12 o'clock noon.

Overview in PDF format (ISBN 951-22-7087-0)   [330 KB]
Dissertation is also available in print (ISBN 951-22-7063-3)

Abstract

The aim of this study was to develop calculation methods for estimating the most important system level performance characteristics of the WCDMA radio network (i.e. network capacity and coverage) in the presence of interference from various sources. The calculation methods described in this work enable the fast design of radio systems with a reasonable degree of accuracy, where different system parameters, propagation conditions and networks as well as frequency scenarios can be easily tested. The work also includes the development and verification of a propagation model for a microcellular environment.

Traditionally, system level performance figures have been retrieved using system simulations where the radio network has been modeled as accurately as possible. This has included base stations and mobile stations, propagation models, traffic models and mobility models. Various radio resource management (RRM) algorithms, such as power controls and handovers have also been modeled. However, these system simulations are very complex and time consuming and typically the models are difficult to modify. The idea behind this work is to use the main statistical parameters retrieved from accurate, case specific propagation models and to use these statistics as input for the developed analytical radio network models. When used as output from these analytical models we are able to obtain the performance measures of the network.

The specific application area for the developed methods is the evaluation of the effect of the interference from the adjacent frequency channels. Adjacent channel interference decreases the efficiency of the usage of the electromagnetic spectrum i.e. the spectral efficiency. The aim of a radio system design is to ensure that the reduction in the spectral efficiency is as low as possible. This interference may originate from the same or a different radio system and from the same or another operator's network. The strength of this interference is dependent on the system parameters and the network layout.

The standard questions regarding adjacent system interference between different operators' network are what guard band is needed between the radio carriers in order to maintain the quality of the network or what are the main mobile and network parameters, such as adjacent channel emission levels or adjacent channel selectivity, required in order to achieve satisfactory network performance. With the developed method proposed here it is possible to answer these questions with reasonable accuracy.

One important aspect of network performance is the radio wave propagation environment for which the radio systems are designed. This thesis presents methods evaluating radio wave propagation, especially for cases where the base station antenna is below the rooftops, i.e. in the case of microcellular network environments. The developed microcellular propagation model has been developed for network planning purposes and it has been verified using numerous field propagation measurements. The model can be used in cases where the mobile station is located either indoors or outdoors.

This thesis consists of an overview and of the following 9 publications:

  1. Heiska K., Posti H., Muszynski P., Aikio P., Numminen J. and Hämäläinen M., 2002. Capacity reduction of WCDMA downlink in the presence of interference from adjacent narrow-band system. IEEE Transactions on Vehicular Technology 51, number 1, pages 37-51.
  2. Heiska K., Posti H., Muszynski P., Rautiainen T. and Numminen J., 2002. WCDMA downlink coverage reduction due to adjacent channel interference. Wireless Personal Communications 23, number 2, pages 217-242.
  3. Heiska K., 2003. Effect of adjacent IS-95 network to WCDMA uplink capacity. IEEE Transactions on Vehicular Technology 52, number 2, pages 326-332.
  4. Heiska K., Rikkinen K., Muszynski P. and Schwarz U., 2003. Modeling of UE-UE interference at 2.5 GHz WCDMA. In: Proceedings of the 14th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'03). Beijing, China, 7-10 September 2003, volume 1, pages 69-73.
  5. Heiska K. and Holma H., 1998. Performance of 2 Mbit/s packet data with WCDMA in small microcellular environment. In: Proceedings of the First International Symposium on Wireless Personal Multimedia Communications (WPMC'98). Yokosuka, Japan, 4-6 November 1998, pages 64-69.
  6. Heiska K. and Kangas A., 1996. Microcell propagation model for network planning. In: Proceedings of the 7th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'96). Taipei, Taiwan, 15-18 October 1996, volume 1, pages 148-152.
  7. Rajala J., Sipilä K. and Heiska K., 1999. Predicting in-building coverage for microcells and small macrocells. In: Proceedings of the 49th IEEE Vehicular Technology Conference (VTC'99). Houston, Texas, USA, 16-20 May 1999, volume 1, pages 180-184.
  8. Heiska K., 2002. Interference between GSM/EDGE and other cellular radio technologies. In: Halonen T., Romero J. and Melero J. (editors), GSM, GPRS and EDGE Performance: Evolution Towards 3G/UMTS. John Wiley & Sons, Ltd., Appendix D, pages 587-597.
  9. Heiska K., 2002. Narrowband and WCDMA system operation in adjacent frequency bands. In: Laiho J., Wacker A. and Novosad T. (editors), Radio Network Planning and Optimisation for UMTS. John Wiley & Sons, Ltd., Section 5.4, pages 232-258.

Keywords: radio wave propagation, WCDMA, capacity, coverage, adjacent channel interference

This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited.

© 2004 Helsinki University of Technology

Last update 2011-05-26