QAM (Quadrature Amplitude modulation) has been widely used in various digital communication systems due to its high modulationefficiency.
正交幅度调制(QAM)具有较高的调制效率，被广泛应用于各种数字通信系统中。
2
Also, optimizing design and analysis showed that the decrease of modulationefficiency due to modulating in claddings can be compensated by appropriately reducing the size of cores.
通过优化设计与分析发现适当降低波导芯层的尺寸可以弥补因包层调制引起的调制效率的下降。
3
The amplitude modulated wave with any modulation factor is discussed in this paper. Its expression, spectrum and formula of the modulation factor, modulationefficiency, SNR gain are given.