IMPROVEMENTS FOR THE RPE-LTP SPEECH CODEC

摘要

The main purpose of this paper is to present some made modifications to standard RPE-LTP codec used in the actual GSM cellular telephony without modifying its structure and therefore without altering the bit rate. The original standard RPE-LTP and three modifications were simulated with a computer software and tested with a subjective quality measurement using the MOS (Mean Opinion Score) test. The modified techniques result in sound quality improvements when we compare them with the original standard.