Simulation and modelling of interference and shadowing in LMCS

by Bronson, J. C.q(James

Recently, efforts are being made to provide broadband services to fixed residential and commercial subscribea through wireless cellular neworks called Local Multipoint Communication Semice (LMCS). In order to compete with established .,;-al- ..,,,me services. ihe prûblem of providiiig rcasoiiabi-; comparable ioveragc musî bé overcome. Generally. there is a lack of specific propagation information at EHF fiequencies. Tnis radio propagation data is required for systems to be designed that can successfully adapt to local propagation environments. The object of this research is to gather field rneasurements and apply the propagation information to simulation and modelling in order to predicr interference and shadowing impairmcnts likely to be cspenenced in an LMCS environment. The field measurements at 29.5 GHz in an urban en~ironment obsexved a parhioss exponent of 4.0 1 for NOS propagation paths. The standard deviation of shadouing expenenced was 13.89 dB and was thus consistent ~lth other research. Simulation shows that the interference expected in a LMCS can significantly impact the performance. A simplified interference mode1 shows that the propagation exponent and standard deviation of shadowing considerably affect outage probabilin. .utenna characteristics such as bearn width. gain ratio. and bearn pattern were also evaluated for their effects on outage. Further, sectoring proved to dramaticallp reduce the outage expenenced at the base station. The distribution of interference powers at a base station is show to have a log-normal disaibution using the Kolmogorov-Smirnov Test. My gratitude goes to Professor David Falconer, my supervisor, for his instruction. =guidance, patience. and encouragement throughout the course of rhis research. His efforts contributed directly to die niccess of this thesis. and to my enjoyment of it. 31. Raben Bultitude ofkrzit me die benefii of hi5 cxptricacè on more than one occasion. 1 am prareful for his assistance during the field measurements portion of this researc hl My dianks also go to Mr. Bob Hahn. firstly. for construcring the radio equipment I used for the fieldwork. and secondly. for graciously providing access to the technicd specifications. John Sydor and Alain Dugais assisted my field work by giving me the benefit of cheir preklous work in the Glebe and facilitating my access to the roof of Glrbe High School. My appreciation goes to the following graduate midents for the beneficial discussions and consultations: Jean-Paul DeCruyenaere. and Sébastien Roy. On severai occasions. they offered their time and energy during bus) periods. Thanks! Special thanks to Nausheen Naz for imcting me on the operation of the CW equipment and especially for the use of her LabView program used to control the CW receiver. Finally, 1 am most -ptefid for the continual support and encouragement of my close fnends and fami-. This work would not have been completed if the. had let me cornplain or procrastinate.