Development of Digital Signal Processing Device for Voice Communication Systems

The task of a final qualifying work is the development of digital signal processing device for voice communication systems. In the final qualifying work was developed a device layout on DSP-based processor, designed to reduce the noise in voice communications systems, taking into account the parameters of the signal and noise characteristics. Digital bandpass filter is designed by analog prototype. In the band-pass filter slightly suppresses noise outside the frequency 300 - 4000 Hz by 60 dB. After passing through the audio filter noise reduction occurs, for bandwidth and the output is an audio file with speech intelligibility. The objective was to improve the filter speech sound transmitted to the listener. The microcontroller is selected on the basis of the analysis of DSP parameters: price, matching options, and availability in the market. The best option was the debug board STM32F4-Discovery. The digital filter is implemented on a microcontroller, which is programmed so that the audio signal is input, process, and the outputs a filtered stream. The system can be used as a debug kit, it can improve itself and produce multiple digital conversions simultaneously. This allows you to use it in a multi-channel audio processing systems.