| 1. | The development of cellular communication , multiple addressing and frequency multiplexing techniques , etc . provides a guarantee for leo satellite mobile communication . in order to improve the flexibility of communication systems , we hope that the a / d , d / a converter should be near rf - end , that is , programmable devices can implement the whole processing in middle frequency
为了使得通信系统具有较大的灵活性和可扩展性，我们希望a d 、 d a变换器尽量向射频端靠拢，即完成射频到中频的下变频后，整个中频的处理都用可编程数字器件以及软件来实现。 |
