Estudo da qualidade da voz em sistemas de comunicação móvel através do CODEC EVS utilizando as métricas de qualidade P.862 e e-model

Abstract

The evaluation of voice quality in telecommunications systems is of utmost importance to ensure effective and satisfactory communication for users. In this research, the algorithms of ITU-T Recommendation P.862 and ITU-T G.107 E-Model were used as standard references to analyze voice quality in communication systems. The methodology used aimed to ensure the accuracy and relevance of the results. Objective tests were conducted in mobile communication scenarios using the EVS (Enhanced Voice Services) and AMR-WB (Adaptive Multi-RateWideband) codecs. The objective of this study was to examine and suggest alternatives that assess user perception and control degradation through unbiased methods for perceptual analysis of audio signals’ quality. Prioritizing Quality of Experience (QoE), the results obtained were of great importance in improving the quality of voice communications in mobile communication systems. During the tests, voice signal encodings and decodings were performed using the EVS codec, both in interoperable mode with AMR-WB and in native EVS mode, using parameters such as DTX (Discontinuous Transmission) and -q. The results showed that voice transmission performance benefited from higher bit rates and the activation of specific transmission condition parameters. The use of parameters such as DTX and -q proved effective in improving voice transmission performance using the EVS codec. DTX is a feature that saves bandwidth by temporarily interrupting voice transmission when no speech is detected. The -q parameter refers to the use of a noise cancellation or silence suppression algorithm during voice quality measurement. The E-Model evaluates voice quality, considering factors such as available bandwidth, bit rate, packet loss, and network latency, also playing a fundamental role in determining the perceived quality by users. In conclusion, the research demonstrated the importance of evaluating voice quality in telecommunications systems and proposed solutions to enhance this quality in real-time communications using EVS and AMR-WB codecs. The results obtained are valuable for improving the quality of voice communications in mobile communication systems, ensuring a better experience for users.