Application of Adaptive QAM Modulation and Diversity Scheme for 30 GHz Cellular Communications under the Impact of Rain Attention in Indonesia

Gamantyo Hendrantoro, Achmad Mauludiyanto, Ninik D. Yundariani

Abstract


In millimeter-wave wireless cellular systems like Local Multipoint Distribution Services (LMDS) rain attenuation is an essential factor of performance degradation. It can cause signal outages and poor quality of signal reception. To mitigate the problem, a combination of diversity and adaptive modulation is proposed. To investigate the impact of the use of these techniques, a simulation is performed for a 30 GHz cellular system to obtain SNR (signalto- noise ratio), diversity gain, modulation level and BER (bit error rate). Analysis of the implementation of the combined techniques is accomplished by taking into account such factors as length of links and the combining method Simulation results show that diversity can improve the overall system SNR. Diversity gain of up to 15 dB can be achieved on two 4-km converging links at 0.01% outage probability when maximal-ratio combining (MRC) is used. For systems with luxurious link design for which the clearsky SNR is more than 30 dB, as considered in this paper, diversity and adaptive modulation do not significantly contribute to improvement of achievable transmission rate and BER performance. However, for systems with lower values of clear-sky SNR, use of both techniques will be more worthwhil.

Keywords


Adaptive Modulation; Diversity; LMDS; Rain Attenuation

Full Text:

PDF

References


Vacca, J.R. Wireless Broadband Network Handbook: 3G, LMDS, Wireless Internet, Mc Graw-Hill. 2001.

Falconer, D., DeCruyenaere, J.-P., “Coverage Enhancement Methods for LMDS”, IEEE Communications Magazine, July 2003, hal. 86-92. 2003.

Salehudin, M., Hanantasena, B., Wijdeman, L. “Ka-Band Lineof- Sight Radio Propagation Experiment in Surabaya Indonesia”, Proc 5th Ka-Band Utilization Conference, Taormina, Italy, hal.161-165. 1999.

Chu, C.-Y., Chen, K.S. “Effects of rain fading on the efficiency of the Ka-band LMDS system in the Taiwan area”, IEEE Transactions on Vehicular Technology, vol. 54, no. 1, Jan. 2005, hal. 9-19. 2005.

Hendrantoro, G., Bultitude, R. J. C., Falconer, D. D. “ Use of Cell-Site Diversity in Millimeter –Wave Fixed Cellular Systems to Combat the Effects of Rain Attenuation”, IEEE Journal on Selected Areas in Communications, Vol. 20, No. 3, hal 602. 2002.

Hendrantoro, G., Indrabayu, Suryani, T., Mauludiyanto, A. “A Mutlivariate Autoregressive Model for Rain Attenuation on Multiple Short Links”, IEEE Antennas and Wireless Propagation Letters, vol. 6. 2006.

Indrabayu, Hendrantoro, G., Suryani, T., Hasanuddin, Z. B. “Diversitas Makro untuk Meningkatkan Kinerja Sistem LMDS pada Kanal Hujan di Indonesia”, Proc. EECCIS, Malang. 2006.

Rappaport, T. S. (2002), Wireless Communications Principles and Practice, ed. 2, Prentice Hall. 2002.

Goldsmith, A.J., Chua, S.G. “Variable-Rate Variable Power MQAM for fading Channels”, IEEE transactions of communication, vol. 45, no. 10. 1997.

Maagt, P. J. L., Touw, S. I. E., Dijk, J., Brussaard, G., Allnutt, J. E. “Results of 12 GHz propagation experiments in Indonesia,” Electronics Letters, vol. 29, hal. 1988-1990. 1993.

Morita, K., Higuti, I., “Prediction Methods for Rain Attenuation Distributions of Micro- and Millimeter Waves”, Review of the Electrical Communication Laboratories, vol. 24, no. 7-8, Jul.- Aug. 1976, hal. 651-668. 1976.

Stallings, W., Data and Computer Communications, ed. 6, Prentice-Hall. 2000.




DOI: http://dx.doi.org/10.12962/j20882033.v18i3.167

Refbacks

  • There are currently no refbacks.


Creative Commons License

IPTEK Journal of Science and Technology by Lembaga Penelitian dan Pengabdian kepada Masyarakat, ITS is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Based on a work at http://iptek.its.ac.id/index.php/jts.