Data transmission over GSM voice channel

Abstract

While the cellular revolution has made voice connectivity ubiquitous in the developing world, data services are largely absent or are prohibitively expensive. GSM voice channel is designed for low-bit rate digitized speech which makes it unsuitable for data communication mainly because of the voice codecs used in GSM. These codecs greatly distort any signal that doesn’t have speech-like properties. This project is about the development of modem for GSM voice channel using speech-like waveform that can go through GSM voice channel without experiencing significant distortion. The objective of this project is to carefully evaluate the recent research developments in the area, design and implement a suitable waveform for real-time data communication over GSM voice channel. GSM voice channel when used for data communication will make wide spread GSM channel attractive for variety of applications. This data transmission will have greater throughput when compared with SMS data service and that too at the lower cost per bit.