Rain attenuation at Ka-band is a severe phenomenon that drastically impairs satellite communications at these frequencies. Several adaptive compensation techniques have been elaborated to counteract its effects and most often applied one at a time. The present paper proposes the contemporary exploitation of different techniques in a combined approach. Such an integrated approach is thoroughly analyzed in a simplified scenario and will be shown to achieve a very effective solution, making the Ka-band spectrum fully available for broadband satellite applications and network-centric systems.
Ka-band satellite communication system has some advantages including a large bandwidth, a huge capacity, a narrow beam, a small terminal size, which makes it a trend in future satellite communications. However, the system is now faced with great challenge-meteorological factors, which aroused suspicion among researchers about its realization. In this paper, the feature of rain fade is analyzed and several compensation methods are presented.
The Ka band for satellite communications is allocated from 27GHz to 40GHz and it is possible to realize the high speed data transmission in this 13GHz bandwidth. However, the attenuation especially the rain attenuation is tremendous for the Ka band. And we need to reserve about 4~8dB link budget to guarantee the typical link reliability 99.9% for the constant coding and modulation (CCM). In this paper, we propose a adaptive coding and modulation (ACM) algorithm that can dynamically change the modulation and code efficiency according to link condition. Based on this algorithm we only need reserve about 1dB to realize the 99.7% reliability. The simulation results show that we can derive more than triple throughout compare to CCM.
A Systemic Approach to the Compensation of Rain Attenuation in Ka-Band Communication Satellites