Variable step closed-loop power control with space diversity for low elevation angle High Altitude Platforms communication channel [Langkah variabel kontrol daya tertutup dengan keragaman ruang untuk sudut elevasi rendah pada kanal komunikasi HAPs]

Iskandar Iskandar, Adit Kurniawan, Mohamad Erick Ernawan


This paper proposes variable step closed loop power control algorithm combined with space diversity to improve the performance of High Altitude Platforms (HAPs) communication at low elevation angle using Code Division Multiple Access (CDMA). In this contribution, we first develop HAPs channel model which is derived from experimental measurement. From our experiment, we found HAPs channel characteristic can be modeled as a Ricean distribution because the presence of line of sight path. Different elevation angle resulting different K factor value.  This value is then used in Signal to Interference Ratio (SIR) based closed loop power control evaluation. The variable step algorithm is simulated under various elevation angles with different speed of mobile user. The performance is presented in terms of user elevation angle, user speed, step size and space diversity order. We found that the performance of variable step closed-loop power control less effective at low elevation angle. However our simulation shows that space diversity is able to improve the performance of closed loop power control for HAPs channel at low elevation angle.


Kajian ini mengusulkan suatu algoritma kontrol daya langkah variabel loop tertutup dikombinasikan dengan keragaman ruang untuk meningkatkan kinerja komunikasi High Altitude Platforms(HAPs) pada sudut elevasi rendah menggunakan Code Division Multiple Access (CDMA). Kami berkontribusi untuk mengembangkan model kanal HAPs yang berasal dari pengukuran eksperimental sebelumnya. Dari percobaan tersebut, kami menemukan karakteristik kanal HAPs yang dapat dimodelkan sebagai distribusi Ricean karena kehadiran jalur tanpa penghalang. Eksperimen menunjukkan bahwa perbedaan sudut elevasi menghasilkan perbedaan nilai factor K. Nilai ini kemudian digunakan dalam Signal to Interference Ratio (SIR) berbasiskan evaluasi kontrol daya loop tertutup. Algoritma langkah variabel disimulasikan dibawah sudut elevasi yang berbeda dengan kecepatan yang berbeda dari pengguna vobile. Kinerja tersebut disajikan dalam hal sudut elevasi pengguna, kecepatan pengguna, ukuran langkah dan ketertiban ruang keanekaragaman. Kami menemukan bahwa kinerja langkah variabel kontrol daya loop tertutup kurang efektif pada sudut elevasi rendah. Namun simulasi kami menunjukkan bahwa ruang keragaman mampu meningkatkan kinerja kontrol daya loop tertutup untuk kanal HAPs di sudut elevasi rendah.


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Chung-Ju Chang, Jeh-Ho Lee, & Fang-Ching Ren. (1996). Design of power control mechanisms with PCM realization for the uplink of a DS-CDMA cellular mobile radio system. IEEE Transactions on Vehicular Technology, 45(3), 522–530.

El-Jabu, B., & Steele, R. (2001). Cellular communications using aerial platforms. IEEE Transactions on Vehicular Technology, 50(3), 686–700.

Foo, Y. C., Lim, W. L., Tafazolli, R., & Barclay, L. (2000). Other-cell interference and reverse link capacity of high altitude platform station CDMA system. Electronics Letters, 36(22), 1881.

Hidayat, D., & Iskandar. (2015). Pilot-based estimation for SC-FDMA LTE in high altitude platforms (HAPS) channel (pp. 1–5). IEEE.

Ilcev, D. S., & Sibiya, S. S. (2015). Weather observation via stratospheric platform stations (pp. 1–12). IEEE.

Iskandar, Kurniawan, A., & Ernawan, M. E. (2010). Performance of Variable Step Closed Loop Power Control in CDMA High Altitude Platforms Communication Channel (pp. 1–5). IEEE.

Iskandar, & Shimamoto, S. (2005). The Channel Characterization and Performance Evaluation of Mobile Communication Employing Stratospheric Platform (pp. 828–831). IEEE.

Iskandar, & Shimamoto, S. (2006). Prediction of Propagation Path Loss for Stratospheric Platforms Mobile Communications in Urban Site LOS/NLOS Environment (pp. 5643–5648). IEEE.

Jong-Min Park, Bon-Jun Ku, Yang-Su Kim, & Do-Seob Ahn. (2002). Interference analysis of cellular system due to HAPS system to provide IMT-2000 service (Vol. 3, pp. 1182–1186). IEEE.

Karapantazis, S., & Pavlidou, F. (2005a). Broadband communications via high-altitude platforms: a survey. IEEE Communications Surveys & Tutorials, 7(1), 2–31.

Karapantazis, S., & Pavlidou, F. (2005b). The role of high altitude platforms in beyond 3g networks. IEEE Wireless Communications, 12(6), 33–41.

Kosmerl, J., & Vilhar, A. (2014). Base stations placement optimization in wireless networks for emergency communications (pp. 200–205). IEEE.

Kurniawan, A. (2003). Predictive Power Control in CDMA Systems. Institute for Telecommunication Research, The University of South Australia.

Pereira, L. S., & Heckler, M. V. T. (2015). Dual-band dual-polarized microstrip antenna for Rx/Tx terminals for high altitude platforms. In 2015 9th European Conference on Antennas and Propagation (EuCAP) (pp. 1–5).

Waluyo, C. B., & Iskandar. (2015). Performance analysis with LMMSE for MIMO LTE on the High Altitude Platform Station (pp. 308–313). IEEE.



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