Data Transmission over GSM Adaptive Multi Rate Voice Channel Using Speech-Like Symbols

This paper introduces a new method to transmit digital data through Global System for Mobile communications (GSM) voice channel. A novel algorithm is proposed to design a set of Speech-Like (SL) symbols which leads to design a GSM voice channel data modem to modulate and demodulate data on GSM Adaptive Multi Rate (AMR) voice codec which consist of different bit-rates. Designing a set of time-symbols is an off line procedure with the aim of minimizing symbol detection error. This modem is useful in real-time data communication with high priority. The introduced modem encodes data into SL symbols to be transmitted over GSM voice channel and the received SL symbols are decoded back to data.