Journal of Siberian Federal University. Engineering & Technologies: Effect of Changing the Symbol Rate of QAM Modem on the Performance of 32kb/s ADPCM System

Journal of Siberian Federal University. Engineering & Technologies / Effect of Changing the Symbol Rate of QAM Modem on the Performance of 32kb/s ADPCM System

Issue: Journal of Siberian Federal University. Engineering & Technologies. 2016 9 (2)
Authors: AL-Rawi, Muhanned; AL-Rawi, Muaayed
Contact information: AL-Rawi, Muhanned:University of Ibb Yemen; E-mail: ; AL-Rawi, Muaayed:AL-Mustansiryia University Iraq;E-mail:
Keywords: QAM modem; 32kb/s ADPCM
Abstract: This paper presents three models of Quadrature Amplitude Modulation (QAM) modem operating at data rate of 16.8kb/s to be transmitted over 32kb/s Adaptive Differential Pulse Code Modulation (ADPCM) channel. These modems operate at symbol rates of 2400, 2800, and 3360 baud with associated number of bits per symbol of 7, 6, and 5 respectively. The performance of ADPCM is studied considering these modems with different constellations. The simulation results show that the performance of ADPCM degrades as the symbol rate decreases or number of bits per symbol increases. Also, the performance with circular constellation is better than rectangular one
Pages: 197-203
Paper at repository of SibFU: https://elib.sfu-kras.ru/handle/2311/20224