Effects of Antenna Tilting on Transmitting Power in Mobile Cellular Communication Systems

Gbenga E. Aderibigbe, Michael O. Kolawole, Victor S. A. Adeloye

.

DOI: 10.4236/ijcns.2011.47056                

Abstract

Radio resources must be wisely managed, in wireless communication systems, when implementing different multiple access techniques. This perspective is pivotal since the variations in propagation channel are very fast and the system is highly complex due to random and unpredictable movement of mobile users continuously. The complexity in the cellular system periodically contributes to different interference levels, high or low, resulting in the degradation of the system capacity. Transmitter power control is an efficient technique to mitigate the effect of interference under fading conditions, combat the Near-Far problem and conserve the battery life. Several remedial measures—like space diversity, frequency diversity, route diversity, increase in antenna height, antenna tilting, etc.—have been tried by many operators to overcome the debilitating effect of multipath fading in fixed line-of-sight microwave and mobile communication links. Among these remedial measures, diversity techniques have been extensively studied in terms of improvement factor, whereas the concept of antenna tilting is relatively less explored compared with other remedial measures. In this study, the effect of antenna tilting on fixed and mobile communication links is investigated to find out the optimum tilting angles in terms of design parameters, as well as on quality of service (QoS). The paper established that a deviation of more than 1.5o in antenna elevation angle would impact on QoS requirements and seriously affect the quality of signal to be received by the mobile systems.

Keywords

Optimum Tilting Angle, QoS, Near-Far Effect, Mobile Station, Carrier-to-Interference Ratio

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	W. J. Hartman and D. Smith, “Tilting Antennas to Reduce Line-of Sight Microwave Link Fading,” IEEE Transactions on Antennas and Propagation, Vol. 25, No. 5, 1977, pp. 642-645. doi:10.1109/TAP.1977.1141662
[2]	M. V. S. N. Prasad, H. N. Dutta, S. K. Sarkar and B. M. Reddy, “Fading Reduction in Microwave LOS Links Using Antenna Beam Tilting Techniques,” Radio Science, Vol. 261, 1991, pp. 751-758.
[3]	M. V. S. N. Prasad, M. M. Gupta, S. K. Sarkar and I. Ahmad, “Antenna Beam Tilting Effects in Fixed and Mobile Communication Links,” Current Science, Vol. 88, No. 7, 2005, pp. 1142-1147.
[4]	G. E. Aderibigbe, “Performance Evaluation of Power control Algorithms in Cellular Radio Communication Systems,” Master’s Degree Thesis, the Federal University of Technology, Akure, 2009.
[5]	M. O. Kolawole, “Satellite Communication Engineering,” Marcel Dekker, New York, 2002. doi:10.1201/9780203910283
[6]	Federal Communications Commission, Washington, D.C. 2001. http://www.fcc.gov/Bureaus/Engineering_Technology/Orders/2001/da010441.txt