A Study of 21GHz Band Advanced Satellite Broadcasting : Countermeasure for Rain Attenuation by Hierarchical Modulation

Abstract

The Communications Research Laboratory (CRL) has been studying an advanced satellite broadcasting system that uses the K-band such as 21 GHz band. The satellite broadcasting in 21 GHz band has much degradation due to rain compared with that in 12 GHz band. Therefore, we propose the hierarchical modulation to realize the "graceful degradation" by controlling the Euclidean distance of the symbol. This report describes the BER characteristics derived from theoretical analysis, and improvement of the frequency utilization efficiency.