Research on Satellite Communication Channel Estimation and Adaptive Modulation Decision Technology

摘要

Satellite communication has become a modern indispensable means of communication. In order to reduce the BER in a maximum limit, the transmitting terminal of adaptive satellite communication technology can automatic select working frequency, data transmission rate and modulation mode. In this study, a simple and practical design of system based on the Signal-to-noise Ratio (SNR) estimation scheme with adaptive modulation for satellite communication is presented. This system applies Maximum-likelihood (ML) algorithm to estimate SNR. Simulation deduces the modulation mode switching threshold. In addition, the adaptive modulation switching threshold is the trade off between spectral efficiency and Bit Error Rate (BER). Furthermore, the modulation mode decision strategy should be considered to achieve the highest spectral efficiency and to maintain constant average BER. The design of an integrated SNR estimation and adaptive modulation mode decision system is highly challenging. Numerical results show that the design fulfills superior performance.