An open-source speech codec at 450 bit/s with pseudo-wideband mode

Publikationstyp
Conference Paper
Date Issued
2019-10
Sprache
English
Author(s)
Erhardt, Stefan  
Kurin, T.  
Lurz, Fabian  
Weigel, Robert  
Kölpin, Alexander  orcid-logo
TORE-URI
http://hdl.handle.net/11420/6984
Start Page
413
End Page
416
Article Number
8904470
Citation
European Radar Conference, EuRAD: 8904470 (2019-10)
Contribution to Conference
16th European Radar Conference, EuRAD 2019  
Scopus ID
2-s2.0-85076213504
Most modern digital speech codecs are proprietary and do not give insights into their implementations. "Codec 2" is an open-source codec and opens up the possibility of application-tailored adaptations. In this publication a new 450 bit/s mode is introduced. It includes a pseudo-wideband mode that can be optionally enabled at the receiver without resulting in a higher bit rate. By sorting the codebook vectors a bit error rate of 10-1 is still intelligible. An encoded audio transmission was tested with two low-power Sub-GHz transceivers in the 70 cm amateur radio band achieving a sensitivity of -130 dBm. For proofing the concept, a field test was conducted and compared to a propagation simulation.
Subjects
Open source software
Radio transceivers
Speech coding
Vocoders