I. Features of Ku-band satellite digital broadcasting.

Compared with the previous C-band satellite analogue broadcasting, Ku-band satellite digital broadcasting has its outstanding features due to the use of higher frequency Ku-band and advanced digital compression technology.

1、Main features of Ku-band satellite broadcasting.

(1) Ku-band satellite single transponder power is generally larger, more fugitive beam coverage, satellite EIRP is larger, plus Ku-band receiving antenna efficiency is higher than C-band receiving antenna, so the receiving Ku-band satellite program antenna aperture is much smaller than C-band, which can effectively reduce the receiving cost and facilitate individual reception;

(2) C-band satellite broadcasting suffers from serious co-channel interference from ground microwave and other interference sources, while Ku-band ground interference is minimal, greatly reducing the requirements of the reception environment;

(3) The impact of rainfall on Ku-band satellite broadcasting is more serious, and its upstream and downstream signal rainfall degradation is much greater than that of C-band, and the instantaneous rainfall degradation of Ku-band uplink or downlink can exceed 20dB under heavy rainfall, while the rainfall degradation of C-band generally does not exceed 1dB.

2、Main features of satellite digital broadcasting

The application of digital compression technology in satellite broadcasting is a major change in radio and television transmission technology. DVB-S satellite digital broadcasting using MPEG-2 video compression standard and MUSICAM audio compression method has incomparable advantages of the analog method, and will undoubtedly replace the traditional analog FM transmission method rapidly in the field of satellite broadcasting.

(1) Digital satellite broadcasting using digital compression technology greatly reduces the video and audio bit rate of transmission, the frequency band and power requirements of the satellite transponder are much lower than those of the analogue method, and the same transponder can broadcast more programmes, significantly reducing the cost of broadcasting programmes;

(2) Satellite digital broadcasting has a very high transmission quality and a very low reception threshold due to the use of powerful error correction algorithms. Unlike the gradual degradation of analogue broadcast reception quality, there is no perceptible distortion, interference or fading of the digital broadcast signal as long as it is at the reception threshold;

 (3) Satellite digital broadcasting offers data transmission and multimedia capabilities and the ability to scramble and authorise, which is particularly beneficial for DTH pay services. Ku-band satellite digital broadcasting combines the characteristics of Ku-band and digital technology, which is ideal for individual reception by decentralised small aperture antennas, especially for satellite radio and television DTH services, while C-band transmission is more favourable for satellite programme distribution services with very high reliability requirements due to the serious rain fade problem in Ku-band.