A high-efficiency speech coding algorithm based on ADPCM with multi-quantizer. - Tomohiko Taniguchi; Kohei Iseda; Shigeyuki Unagami; Syozi Tominaga (ICASSP, 1986)

A 16 kbps ADPCM with multi-quantizer (ADPCM-MQ) codec and its implementation by digital signal processor. - Tomohiko Taniguchi; Shigeyuki Unagami; Kohei Iseda; Yukou Mochida; Syozi Tominaga (ICASSP, 1987)