Change search
ReferencesLink to record
Permanent link

Direct link
Analysis of Radio Channel Measurements Using Multiple Base Stations
KTH, School of Electrical Engineering (EES).
2007 (English)Licentiate thesis, monograph (Other scientific)
Abstract [en]

Future wireless communication systems will utilize the spatial properties of the wireless channel to improve the spectral efficiency and thus increase capacity. This is realized by deploying multiple antennas at both the transmitter and receiver. Utilizing the spatial properties of the channel demands channel models that properly reflect these characteristics. Due to the unpredictable nature of the wireless channel, a common approach is to model its effects in a statistical fashion. A few large world wide cooperations, like the 3GPP or WINNER projects, have developed channel models intended for reference and standardization use. These models are partly based on bulk parameters which describe the characteristics of the channel over larger areas of several wavelengths. These parameters include shadow fading, angle spread, and delay spread among others, and are within the WINNER project called large scale (LS) parameters. Considering the variations of these parameters, it is likely that they are correlated between closely located areas. Therefore it is of key interest to model their correlation properties instead of randomizing them independently for each new simulation. In multi-cell scenarios, when considering macro diversity or evaluation other properties such as interference and/or handover schemes, the intra site correlation of the shadow fading parameters should be taken into account for proper simulations. Neglecting this correlation the interference could be over/under estimated, hence the system capacity can be over/under estimated. Further, reliable estimations of the interference levels will increase the frequency reuse, and may even permit reuse within the same cell, on spatially separated links. The thesis focuses on modelling the statistics and variations of these parameters to increase accuracy of channel models. Previous studies have looked at the autocorrelation properties of the shadow fading in outdoor environments and found it to follow an exponential decay. This means that an first order autoregressive function would be sufficient to model this effect. Research of the angular spread parameter is more scarce, and therefor this issue is studied herein. In addition to the autocorrelation properties the intra-site correlation between the different large scale parameters is of interest. It is herein found that the shadow fading is negatively correlated with angle spreads, while the angle spread at the base station and the angle spread at the mobile show positive correlation. Finally, the inter site correlation between one mobile and multiple base stations is studied as a function of the angular separation between the links. For closely located base station, ie with small angular separation as seen from the mobile, substantial inter-site correlation is found. It is further seen that the correlation of the shadow fading is more prominent than the correlation of angle spread.

Place, publisher, year, edition, pages
Stockholm: KTH , 2007. , xiv, 131 p.
Trita-EE, ISSN 1653-5146 ; 2007:019
Keyword [en]
Channel Modellin
National Category
URN: urn:nbn:se:kth:diva-4352ISBN: 978-91-7178-643-2OAI: diva2:11927
2007-05-08, L1, Drottning Kristinas väg 30, 100 44 Stockholm, 13:15
QC 20101109Available from: 2007-05-04 Created: 2007-05-04 Last updated: 2010-11-09Bibliographically approved

Open Access in DiVA

fulltext(7046 kB)2197 downloads
File information
File name FULLTEXT01.pdfFile size 7046 kBChecksum SHA-1
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Jaldén, Niklas
By organisation
School of Electrical Engineering (EES)

Search outside of DiVA

GoogleGoogle Scholar
Total: 2197 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 538 hits
ReferencesLink to record
Permanent link

Direct link