To provide a self-correlation coefficient computing element with which the sum of products is speedily operated with low power through the encoding technique of audio signals, etc., in order to operate a self-correlation coefficient.
An analog input signal S is inputted to an analog desample/ hold circuit 2, digitized by an A/D converter 3 on the other hand and inputted to a delay circuit 4. A digital signal SP inputted to the delay circuit 4 is held in the delay circuit 4 while successively applying prescribed delay and synchronously with the timing of delay at the delay circuit 4, on the other hand, the analog signal S inputted to the sample/hold circuit 2 is sampled and held in this sample/hold circuit 2. At the time point when the sample/hold circuit 2 holds the prescribed number of sample values, corresponding to a clock CK from a clock generating circuit 1, these sample values are simultaneously outputted, delay values held in the delay circuit 4 are outputted while being successively delayed and shifted corresponding to a shift clock SCK, and a weight synthesizing circuit 5 outputs a self-correlation coefficient R by operating the sum of products of these sample values and delay values.
SHU NAGAAKI
KOTOBUKI KOKURIYOU
YOZAN KK