ONE-BIT SIGNAL DOWN-SAMPLING APPARATUS, DOWN-SAMPLING METHOD, MULTI-CHANNEL AUDIO APPARATUS, AND VOICE REPRODUCING METHOD OF MULTI-CHANNEL AUDIO APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a down-sampling apparatus which does not require a filter coefficient table, a multiplier, or the like, which can be realized with a small circuit scale, moreover, which can operate at a low sampling frequency, and thus can be reduced in power consumption, and to provide a down-sampling method.;SOLUTION: A triangular window curtain bit expansion part 43 expands one bit signal of 2.8224 MHz into 7 bits by multiplying the signal by a triangular window function. An adding+thinning circuit part 44 accumulates the 7 bit signal of 2.8224 MHz from the triangular window curtain expansion part 43, and performs down-sampling of this accumulated signal with a sampling frequency (88.2 kHz), and obtains a 14 bit signal of 88.2 kHz. Here, what one bit signal of 2.8224 MHz inputted from an input terminal 42 is weighted by the triangular window function at the triangular window curtain bit expansion part 43 is accumulated by the adding+thinning circuit part 44 and thereby a convolution integral is carried out.;COPYRIGHT: (C)2006,JPO&NCIPI