• The Journal of the Acoustical Society of Korea
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• v.18 no.8
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• pp.100-107
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• 1999

When a subscriber service composed along the central street of urban in microcell and picocell mobile communication of cellular method, we proposed the propagation prediction model that mobile communication environment of urban can analyze exactly and faster men than a precedent. We simulate the proposed propagation prediction model under the urban propagation environment of PCS mobile communication and analyze distribution of received field strength in cell. As a results, we show the optimal condition of the transmitting power and the position of the base station in the microcell and the picocell mobile communication.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.5 s.108
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• pp.430-439
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• 2006

This paper presents the a measured path-loss characteristics for mobile communications beyond 3G in microcellular residential area and street microcell at 3.4, 5.3, and 6.4 GHz band signals. The residential area is divided into two sections, one of which is composed of fifteen-story appartment buildings. The other section comprises four-story houses. The street microcell is classified line-of-sight(LOS) and nonline-of-sight(NLOS) areas. Both residential areas have standard deviations independent of the residential area classification, whereas the path loss exponents in the apartments is higher than those in area for same frequencies. A two-ray model is applied to analyse the path-loss charateristics in LOS areas. In LOS areas, an empirical breakpoint, whose distance is 6 percent shorter than a theorical breakpoint, is founded. Further, a sudden power level drop occurs at a transition point from LOS region to NLOS area. Path loss exponent is found to be significantly higher for non-LOS region than for LOS region. The power level drop due to corner loss and path-loss exponents both increase as the distance between the transmitter and the corner increases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5A
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• pp.517-525
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• 2008

In this paper, we cary out system level simulations to investigate the effect of cell shape(i.e., different base station displacements in the two directions defined by the street grid) on minimizing transmitter power, interference power, and blocking probability for CDMA system in urban microcellular environments. In urban microcell, path loss to the base station depends on the orientation of the street where the mobile is located. Interference from mobile stations to the base station in the reference cell is considered up to second tier. The wrap around method is used to include the second tier interference with realistic computational complexity without reducing the accuracy of interference calculations. The investigation shows that the transmitter power, interference power, and blocking probability in a cell can be reduced by proper selection of the efficient cell shape.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4A
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• pp.238-246
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• 2003

In this paper, we will provide a comprehensive review of radio propagation measurements conducted to date for mobile radio systems at frequency bands used for cellular and personal communications services in microcellular systems. Path-loss results were measured by using narrowband signal and multipath propagations were characterized by wideband measurements. This paper includes unpublished empirical path loss formulas for Oakland city of non-uniform building heights, and presents a comparison with path loss formulas obtained from typical low-rise building environments in order to discuss street grid dependence on route-specific building profile. We will also compare some empirical models developed based on the measurements with a few well-established theoretical prodiction models.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.3B
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• pp.153-160
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• 2007

Placing antennas of low power base stations below surrounding buildings, as in urban microcells, makes propagation characteristics strongly dependent on the building environment. As a result, propagation in these urban microcells is non-isotropic, so that the assumption of circular cells used in planning of conventional cellular sys toms is no longer valid. Assuming circular cells leads to a more conservative system design, implying more base stations. This work investigates the effect of cell shape, due to non-isotropic propagation, on the out-of-cell interference and Erlang capacity of CDMA system. Propagation is described by measurement derived models for low antennas in a rectangular urban street grid. The analysis is done for soft handoff protocols.