信号重畳方式における衛星非線形特性の補償技術

摘要

In the power limited satellite system it is mandatory to use the transponder amplifier effectively as far as possible. High transmission efficiency cab be achieved not only by adopting frequency super-positioning scheme but also by transmitting signal in the saturated region of satellite power amplifier. When the signal is transmitted in the saturated region, it is suffered from the nonlinear effects of the amplifier. It is therefore very important to study the effects of nonlinearity on to the performance of interference canceller. Therefore, in this study, a scheme of post- compensation of the nonlinearity is proposed here to put in front of the canceller to reduce the effects of it and to improve the transmission performance. The effects of nonlinearity on to the PSK signal without compensation is shown first, and then it is shown by computer simulation that the proposed scheme works well for compensating nonlinearity.%静止衛星通信の高速大容量化と電力の利用効率の改善を実現させる手法として，多値変調信号を用いた衛星通信キャリア重畳方式が検討されている．これまでの研究では，P-MP 衛星通信システムにおける衛星通信キャリア重畳方式を利用しながら，増幅器の非線形補償技術によって電力の利用効率を改善する手法が提案されている．しかし，従来までの手法ではP-P 衛星通信システムには対応していない．そこで，本報告ではP-P 衛星通信システムにおけるキャリア重畳方式を用いた衛星中継器の非線形歪みを補償する手法を提案し，評価する．