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Abstract-A microcell interference model termed the Nakagami m , / m , is introduced in this paper. The desired signal as well as the cochannel interferers are assumed to have Nakagami statistics but with different amounts of fading. A special case of this model is obtained when the desired signal has Nakagami statistics while the cochannel interferers are subject to Rayleigh fading. The probability density function of the signal-to-interference ratio in the Nakagami m , / m , model is derived. This model is also compared with a Rician/Rayleigh microcellular model. The Nakagami m , / m , model is chosen to investigate the microcellular systems because Nakagami distributions fit experimental data better than either Rayleigh or Rician distributions in many cases. Expressions for the outage probabilities in microcell systems are derived. Numerical results show that, compared to medium/large cell systems, the microcellular systems have a lower outage probability. The impact of diversity on the microcellular system is also studied. Both signal-to-noise plus interference ratio selection diversity and signal-plus-interference selection diversity are investigated and an improvement to the outage probability due to diversity is observed.

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This paper describes the results of propagation measurements carried out in an office complex at 946 :MHz with three objectives: to investigate the impact of desk population on the average propagation loss, to model average path loss, and to fit a statistical description tot the measured results. The measurements were conducted on two identically structured floors: one fully occupied and the other completely empty. The loss in the fully occupied floor is found to be consistently higher, but the: propagation loss factor is more uniform in different directions from the base. Fade margin statistics were obtained for mean signal power levels which are between !50 dB and 60 dB less than the signal power at the base. We find that the Nakagami fading model fits the results better than the generally accepted model in Rayleigh fading. IntroductionRecent advances in portable and mobile communication systems have accelerated research in understanding radio propagation mechanisms which could lead to spectrally more efficient systems which are easier to design and relatively inexpensive to install. This paper is an effort to reach this god. The measurement program was initiated to learn more about the propagation mechanism to help design CT2PLUS based systems in confined ;Keas. For this purpose open floor plan environments were chosen to investigate effect of walls and hard partitions on propagation modeling. Of interest is how sensitive ithe model radio channel parameters are to open floor plans which are either empty or populated. The paper is organized as follows. Section 2 details the equipment and measurement procedures, system calibration and measurement results. These results are analyzed in section 3. Section 4 sums up the conclusions. Signal Measurements The EnvironmentThe measurements were carried out on two identically structured floors: one fully occupied and the other completely empty. Both floors have identical dimensions: 20 meters wide and 50 meters long, with 2.7 meter high ceilings. The ceilings are suspended on metal grids. Both floors contain pillars made of concrete and ferrous material located on an eight by eight meter grid. The floors are bounded on three sides by concrete walls containing ap-0-7803-1266-~/93/$3.00019931EEE 73 proximately 50% window surface area.The occupied floor contains seventy five desks which are stationed along three long and three short corridors in an open floor plan. Each desk is surrounded by partitions with metallic cores covered by cloth. There is approximately one desk per thirteen square meters. This density level is near the maximum [ 11 used for traffic calculated for indoor personal communications. The empty floor is dimensionally the Same but is devoid of people, desks and partitions. Measurement Set-up946 MHz was chosen as a carrier frequency because it is at the center of the spectrum assigned to the CT2Plus Class 2 system in Canada. Measurement data was obtained at the receiving end by using a spectrum analyzer which samples the signal envelope at 40 &/sec over a o...

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