Based upon a number of received user codes, a receiver defines a frame of symbols containing at least one window. 根据一组收到的使用者编码,接收器定义了含有至少三个符号之视窗的画面。
It serves as the signal generator in a transmitter and in a receiver, and the local oscillator is used together with a mixer to convert the received RF signal to an IF signal. 它在传输器跟接收器中是作为标准的讯号产生器,本地震荡器通常是跟混波器一起使用将射频讯号转换到中频。