| 摘要 |
An analog-to-digital converter especially suited for seismic data recording applications operates using the differential pulse code modulation method. A digital linear predictor 40 is used to generate a digital predicted input signal, which is converted in a digital-to-analog converter 44 to an analog signal which is directly compared to the actual input signal 42. The error signal thus generated is converted 34 to a digital error signal for addition 38 to the predicted signal prior to transmission to means for recording the output signals, and is used for updating of the predicted signal according to the linear predictor 40. Quantization noise is reduced by highly oversampling the input signal, and a low pass filter 46 smooths the digital output signals. <IMAGE> |
