Digital be - subando de - sutori of the ta signal - generate mu method and the device

摘要

PURPOSE: To reduce a memory which generates proper time delay by lowering a sample speed. CONSTITUTION: The amplitude of an analog signal input is converted into a stream of digital data words at a maximum conversion speed equal to a 2nd speed of F samples per second in response to a sample strobe S signal. The stream of the data words is demodulated into digital form to find the stream of base-band data words, and respective streams of base-band data words are passed through digital low-pass filters 26-1-26-2. Then the streams of the filtered data words are reduced by a selected subtrahend coefficient D to find an output signal which is a stream of data words generated at a reduced 1st speed of F' samples per second. Consequently, the operation speed and the necessary depth of a channel time delay RAM can be reduced.