Taha-Ahmed, B., M. Calvo-Ramon, and L. de Haro-Ariet,  "High altitude platforms (HAPs) W-CDMA system over cities",  Vehicular Technology Conference, 2005. VTC 2005-Spring. 2005 IEEE 61st, vol. 4, pp. 2673-2677 Vol. 4, May, 2005.

Taha-Ahmed, B., M. Calvo-Ramon, and L. de Haro-Ariet,  "Down-link analysis of a FDSS-GSM overlay system",  Vehicular Technology Conference, 2004. VTC 2004-Spring. 2004 IEEE 59th, vol. 5, pp. 2502-2506, May, 2004.

Ahmed, B. T., M. C. Ramon, and L. H. Ariet,  "LEO satellite W-CDMA downlink pole capacity",  Wireless Technology, 2004. 7th European Conference on, pp. 173-176, Oct, 2004.

Ahmed, B. T., M. C. Ramon, and L. H. Ariet,  "Quasi-optimum downlink power control of high altitude platform W-CDMA system",  Vehicular Technology Conference, 2003. VTC 2003-Spring. The 57th IEEE Semiannual, vol. 4, pp. 2476-2479 vol.4, April, 2003.