Simple DCT-based speech coder for Internet applications
Cheuk Fai Kwong, Wing Man Pang, Hon Cheung Wu, Keang-Po Ho · 2003
A very simple speech coder 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 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 coding for wireless applications, low data-rate speech of 4 kbit/s can be achieved with a signal-to-noise ratio (S/N) of about 11 dB, comparable to 8 kbit/s VSELP and CS-ACELP speech coder.