Abstract.A very simple speech coder is investigated based on modified discrete-cosine transform (MDCT), run-length coding, and entropy code. The speech signal is first passed through a MDCT, quantized by a uniform quantizer, and run-length coded to achieve good compression ratio. Not suitable for wireless communication systems, the speech coder is perfect for Internet and speech storage applications. With a performance far better than most speech coders for wireless applications, low data-rate speech of 3 kbit/s can be achieved with a signal-to-noise ratio (S/N) of about 12 dB.

A bstructA very simple speech lcoder is investigated based on discrete-cosine transform (DCT) and run-length coding. The speech signal is first passed through a DCT, quantized by a uniform quantizer, and runlength coded to achieve good compression ratio. Not suitable for wireless communication systems, the speech coder is perfect for Internet and speech storage applications. With a performance far better than most speech coding for wireless applications, low data-rate speech of 4 kbit/s can be achieved with a signal-tonoise ratio (S/N) of about 11 dB, comparable to 8 kbit/s VSELP and CS-KELP speech coder. 0-7803-5284-X/99/$10.00 0 1999 IEEE.