A study of UMTS terrestrial radio access performance

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Doctoral thesis (article-based)
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Date
2003-10-24
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Degree programme
Language
en
Pages
80, [101]
Series
Technical report / Helsinki University of Technology, Communications Laboratory. T, 49
Abstract
This thesis considers the performance evaluation of third generation radio networks, in particular UMTS Terrestrial Radio Access (UTRA). First, the performance evaluation methods are presented. The typical capacity of UTRA is estimated using those methods and a few solutions are evaluated to improve the capacity and coverage. The thesis further studies the effect of base station synchronization on the performance of UTRA time division duplex mode. The performance evaluation is based on the combination of theoretical calculations, link and system level simulations, and laboratory and field measurements. It is shown that these different evaluation methods give similar results and – when combined together – they can be used for the radio network development purposes. The simulation results indicate that the typical WCDMA, i.e. UTRA frequency division duplex mode, macro cell capacity is between 600 and 1000 kbps per sector per 5 MHz. The capacity is sensitive to the environment and to the transceiver performance. The results further show that user bit rates up to 2 Mbps can be provided locally for packet data with the basic Rake receiver, but not for full coverage circuit switched connections in macro cells. The following performance enhancement techniques are evaluated in this thesis: soft combining of packet retransmissions, base station multiuser detection and 4-branch base station receiver diversity. The link level simulations show that soft combining can provide a gain up to 2.0 dB, which can be used to increase the capacity up to 60 %. The performance of base station multiuser detection is evaluated with link and system level simulations. It is shown that the studied sub-optimal multiuser detector is able to remove 60-70 % of the intra-cell interference. That gain can be utilized to improve the uplink capacity by 50-100 % or the coverage by 1-2 dB. The performance of 4-branch antenna diversity is evaluated in the simulations and in the field measurements. The results show that the average coverage gain of 4-branch diversity with two separate cross-polarized antennas is 3 dB compared to 2-branch diversity with one cross-polarized antenna. The synchronization requirements of UTRA time division duplex base stations are studied with system simulations. The results show that synchronization is a key requirement for time division duplex operation, especially for the uplink performance. The study indicates that co-location of different operators' base stations is feasible in time division duplex operation only if the two networks are synchronized and if an identical split between uplink and downlink is used.
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Keywords
wideband code division multiple access (WCDMA), radio network simulations, capacity, multiuser detection, antenna diversity
Other note
Parts
  • Westman T. and Holma H., 1997. CDMA system for UMTS high bit rate services. Proceedings of the IEEE Vehicular Technology Conference (VTC'97). Phoenix, Arizona, USA, 4-7 May 1997, pages 825-829. [article1.pdf] © 1997 IEEE. By permission.
  • Pehkonen K., Holma H., Keskitalo I., Nikula E. and Westman T., 1997. A performance analysis of TDMA and CDMA based air interface solutions for UMTS high bit rate services. Proceedings of the IEEE International Symposium on Personal, Indoor and Mobile Radio Conference (PIMRC'97). Helsinki, Finland, 1-4 September 1997, pages 22-26. [article2.pdf] © 1997 IEEE. By permission.
  • Hämäläinen S., Holma H., Toskala A. and Laukkanen M., 1997. Analysis of CDMA downlink capacity enhancements. Proceedings of the IEEE International Symposium on Personal, Indoor and Mobile Radio Conference (PIMRC'97). Helsinki, Finland, 1-4 September 1997, pages 241-245. [article3.pdf] © 1997 IEEE. By permission.
  • Hämäläinen S., Slanina P., Hartman M., Lappeteläinen A. and Holma H., 1997. A novel interface between link and system level simulations. Proceedings of the ACTS Mobile Telecommunications Summit'97. Aalborg, Denmark, 7-10 October 1997, pages 599-604.
  • Toskala A., Hämäläinen S. and Holma H., 1998. Link and system level performance of multiuser detection CDMA uplink. Wireless Personal Communications 8, No. 3, pages 301-320. [article5.pdf] © 1998 by authors and © 1998 Kluwer Academic Publishers. By permission.
  • Holma H., Toskala A. and Latva-aho M., 1998. Asynchronous wideband CDMA for IMT-2000. Telecommunications Review 8, No. 6, pages 1007-1021. [article6.pdf] © 1998 by authors and © 1998 SK Telecom. By permission.
  • Raitola M. and Holma H., 1998. Wideband CDMA packet data with hybrid ARQ. Proceedings of the IEEE International Symposium on Spread Spectrum Techniques & Applications (ISSSTA'98). Sun City, South Africa, 2-4 September 1998, pages 318-322. [article7.pdf] © 1998 IEEE. By permission.
  • Holma H. and Heiska K., 1999. Performance of high bit rates with WCDMA over multipath channels. Proceedings of the IEEE Vehicular Technology Conference (VTC'99 Spring). Houston, USA, 16-20 May 1999, pages 25-29. [article8.pdf] © 1999 IEEE. By permission.
  • Hämäläinen S., Holma H. and Sipilä K., 1999. Advanced WCDMA radio network simulator. Proceedings of the IEEE International Symposium on Personal, Indoor and Mobile Radio Conference (PIMRC'99). Osaka, Japan, 12-15 September 1999, pages 951-955. [article9.pdf] © 1999 IEEE. By permission.
  • Holma H., Lehtinen O., Toskala A. and Heikkinen S., 2000. Interference considerations for the time division duplex mode of the UMTS Terrestrial Radio Access. IEEE Journal on Selected Areas in Communications: Special issue on Wideband CDMA 18, No. 8, pages 1386-1393. [article10.pdf] © 2000 IEEE. By permission.
  • Tölli A. and Holma H., 2000. Comparison of WCDMA uplink antenna solutions with 4 receiver branches. Proceedings of the CDMA International Conference (CIC). South Korea, 25-28 October 2000, pages 57-61. [article11.pdf] © 2000 CIC. By permission.
  • Holma H. and Tölli A., 2001. Simulated and measured performance of 4-branch uplink reception in WCDMA. Proceedings of the IEEE Vehicular Technology Conference (VTC'2001 Spring). Greece, 6-9 May 2001, pages 2640-2644. [article12.pdf] © 2001 IEEE. By permission.
  • Holma H., Soldani D. and Sipilä K., 2001. Simulated and measured WCDMA uplink performance. Proceedings of the IEEE Vehicular Technology Conference (VTC'2001 Fall). Atlantic City, NJ, USA, 7-11 October 2001, pages 1148-1152. [article13.pdf] © 2001 IEEE. By permission.
Citation
Permanent link to this item
https://urn.fi/urn:nbn:fi:tkk-000877