Waveform signal compression and expansion along time axis having different sampling rates for different main-frequency bands

• Main Authors: Kikumoto, Tadao, Hoshiai, Atsushi, Kusakabe, Satoshi
• Format: Patent
• Language: English
• Published: 13.05.2003

1. Field of the Invention An apparatus and method for compression and expansion of a wave signal on a time axis. A memory device stores waveform data representative of a waveform for each sub-frequency band of each main-frequency band of a wave signal, in which the wave signal is divided into a plurality of the main-frequency bands, each of the main-frequency bands is divided into a plurality of the sub-frequency bands. A plurality of time axis compression and expansion devices are provided for each of the sub-frequency bands for performing time axis compression and expansion of the waveform. A mixing device mixes signals provided from the time axis compression and expansion devices. Each of the time axis compression and expansion devices performs compression and expansion in a sampling rate that corresponds to one of the main-frequency bands that includes the sub-frequency band that is subject to the waveform time axis compression and expansion, wherein the sampling rate of at least one of the main-frequency bands is different from the sampling rate of at least one other of the main frequency bands.