Sensitivity analysis of Quadrature Amplitude Modulation over AMR-WB voice codec

The voice calls over cellular networks are encrypted only over small sections of the full path, usually only between the Mobile Equipment and the Base Station/eNodeB. In this paper we propose a solution for highly secure end-to-end voice calls over the already existing voice call. As opposite to data channels, the normal audio channel provides low lag, low jitter and increased security due to the peer-to-peer nature of the connections. The challenge to be resolved is to find the methods for transmitting data over current and upcoming vocoders. This paper presents the first and extensive sensitivity analysis of the QAM modulation parameters over the AMR-WB vocoder. The data transfer speeds and bit error rates achieved over AMR-WB vocoder, are 1600bps with SER 2.2∙10, 2000bps with SER 1.5∙10, 3200bps with SER 2.4∙10 or 4000bps with SER 8∙10. The work also presents the modifications of SER and bitrate against parameters ranging from carrier frequency, number of points in the QAM constellation, pulse shape type, roll-off factor and AMR-WB codec rates. This study aims to provide the grounds for further research on solutions for data transfer over the voice codecs of the new generation of cellular networks. Keywords—AMR-WB; AMR-NB; HD Voice data; modem over voice codec; QAM modulation; end-to-end security; data privacy; ubiquitous data communication