Abstract:
A data compression system comprises an analog-to-digital converter for quantizing the analog signal at a first sampling frequency into a series of digital samples and a memory for storing the digital samples. A control circuit generates a sampling datum indicating a variable sampling frequency lower than the first sampling frequency as a function of the instantaneous frequency of the analog signal for selecting digital samples from the memory, reads the selected digital samples out of the memory means in response to the sampling datum, and forms the sampling datum and the selected digital samples into a data set. A series of data sets may be transmitted to a receiving end of the system or stored in a recording medium. The sampling datum is used to indicate the point at which the digital sample is converted to a corresponding analog value.
Abstract:
In a data compression system, a digital signal comprising a series of digital samples and a sampling datum associated with each digital sample is received by a decoder. The sampling datum indicates the sampling interval of the associated digital sample. The decoder includes a microcomputer for storing the digital signal into a memory (M2) and reading each digital sample and the associated sampling datum. The digital sample is divided by the sampling datum to derive a quotient which indicates the slope of the signal to be recovered. The quotient is integrated by an integrator (6b) to provide interpolation between successive sampling points, so that the original signal is approximated by a plurality of line segments.
Abstract:
본 발명은 전원전압을 자동으로 검출하여 전원전압의 변화에 따라 출력전압 범위를 자동으로 변화시켜 항상 최대 출력전압 범위로 제어할 수 있는 전력 증폭기의 디지털 아날로그 변환기(Digital to Analog Converter; 이하 DAC)를 개시한다. 이를 위해, 전원전압과 기준전압을 비교하여 그 비교 결과 값에 해당하는 트리밍(trimming) 데이터를 출력하는 전력 검출부와, 인에이블 신호에 의해 제어되어 기준전압 및 트리밍 데이터를 이용하여 디지털 신호에 해당하는 출력전압을 발생하는 전압 발생부를 포함하는 것을 특징으로 한다.