Generating Dual-Channel Analog Voice Signals Using Simulink

This document demonstrates the generation of dual-channel analog voice signals using MATLAB Simulink. The implementation begins with Pulse Code Modulation (PCM) encoding, where signals are sampled at 8 kHz (standard telephony rate) and quantized using μ-law companding for optimized dynamic range. Following encoding, time-division multiplexing combines both signals into a single data stream through interleaving techniques, implemented via Simulink's Buffer and Selector blocks.

The transmitted signal undergoes Differential Phase Shift Keying (DPSK) modulation, utilizing a carrier frequency of 100 kHz with non-coherent detection to avoid phase synchronization issues. The communication chain employs three core modules: Simulink for system modeling, Communications Toolbox for modulation/demodulation operations using comm.DPSKModulator and comm.DPSKDemodulator objects, and Signal Processing Toolbox for FIR filter design and spectral analysis using fvtool.

The course design report elaborates on system architecture, including parameter configurations for quantizer levels (128 levels for 7-bit PCM) and multiplexing frame structure. Experimental results analyze bit error rate (BER) performance under AWGN channel conditions using berawgn function, with comparative eye diagrams generated through comm.EyeDiagram system object.

This detailed technical breakdown enhances understanding of digital communication system implementation, providing practical insights for educational and research applications in signal processing and telecommunications.