Key Technologies of High Speed Modulator for Satellite Data Transmission

DT system is an important means of satellite remote sensing investigation and surveying and mapping data acquisition and distribution. It mainly includes satellite DT system, ground receiving system, relay satellite system, relay ground receiving station and ground data processing center. In the field of DT, the DT capacity between satellite and ground mainly depends on the transmission rate and transmission time. The transmission rate mainly depends on the satellite ground link. With the increase of transmission rate, the traditional X-band system can no longer meet the requirements of code rate and bandwidth. Although the use of high-order modulation can reduce the requirements of channel bandwidth, the increase of modulation and demodulation loss does not significantly improve the quality of the whole data link. In this paper, the key technologies of satellite DT high-speed modulator are studied and analyzed, the application design scheme of satellite DT and the transmission mode design of high-speed modulator system are discussed, the algorithm of satellite channel characteristics is proposed, and the simulation experiment and test analysis of satellite DT high-speed modulator are carried out. The test results show that the symbol error rate will increase with the increase of modulation order; The minimum error symbol of the test is 0.0048 and the maximum is 0.1. Considering that the bit error rate and hardware implementation complexity will increase with the increase of modulation order, the effectiveness of the key technology of satellite DT high-speed modulator proposed in this paper is also confirmed.