A speech codec for cellular radio at a gross bit rate of 11.4 kb/s

A speech codec, called TRPE-HLTP (transformed binary regular pulse excitation, high-resolution long-term prediction) has been developed. It has been submitted as a candidate for the half-rate codec in the GSM (Group Special Mobile) system and its gross bit rate is 11.4 kb/s. The speech coding algorithm is of the type often called analysis-by-synthesis linear prediction. Its key elements are LSF (line spectral frequency)-coded spectral parameters, a high resolution closed-loop adaptive codebook, and a speech-trained low-complexity transformed binary regular pulse innovation generator, resulting in a net bit rate of 6.9 kb/s. The channel coding scheme consists of forward error correction with convolutional encoding, interleaving, and error detection