1. Improved error resilience for volte and VoIP with 3GPP EVS channel aware coding
- Author
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Daniel J. Sinder, Jeremie Lecomte, Benjamin Schubert, Duminda A. Dewasurendra, Atti Venkatraman S, Venkata Subrahmanyam Chandra Sekhar Chebiyyam, Subasingha Shaminda Subasingha, Lei Miao, Vivek Rajendran, Imre Varga, Venkatesh Krishnan, and Xingtao Zhang
- Subjects
Voice activity detection ,Computer science ,business.industry ,Mean opinion score ,Speech recognition ,Speech coding ,Constant bitrate ,Codec ,PSQM ,Forward error correction ,business ,Decoding methods ,Computer network - Abstract
A highly error resilient mode of the newly standardized 3GPP EVS speech codec is described. Compared to the AMR-WB codec and other conversational codecs, the EVS channel aware mode offers significantly improved error resilience in voice communication over packet-switched networks such as Voice-over-IP (VoIP) and Voice-over-LTE (VoLTE). The error resilience is achieved using a form of in-band forward error correction. Source-controlled coding techniques are used to identify candidate speech frames for bitrate reduction, leaving spare bits for transmission of partial copies of prior frames such that a constant bit rate is maintained. The self-contained partial copies are used to improve the error robustness in case the original primary frame is lost or discarded due to late arrival. Subjective evaluation results from ITU-T P.800 Mean Opinion Score (MOS) tests are provided, showing improved quality under channel impairments as well as negligible impact to clean channel performance.
- Published
- 2015