E XPERIMENT ON C OMMUNICATION E NGINEERING I Course No.- EE-3206 Prof. Dr. Md. Rafiqul Islam Md. Nur Kutubul Alam
N AME OF THE E XPERIMENT Analog: Amplitude modulation (AM) Frequency modulation (FM) Communication using Pulse PAM (Pulse Amplitude modulation) PWM PCM Digital: Analog to digital conversion by PCM system Study on delta modulation Digital signal transmission by ASK, FSK, and PSK modulations
AM VS FM
A MPLITUDE MODULATION (AM) Internal source of Base band signal (Voice band) External source of Base band signal (Voice band) Double side band (DSB) signal generator Single side band (DSB) signal generator Amplifier
F REQUENCY MODULATION (FM)
A NALOG COMMUNICATION USING P ULSE In this communication technique, some samples of original signal is transmitted. Each of the sample of original signal looks like a pulse. Pulse Amplitude modulation (PAM) Pulse width modulation (PWM) Pulse position modulation (PPM) This process increases the capacity of the system.
C OMMUNICATION USING PULSE
S AMPLING TECHNIQUE Minimum sampling rate
S AMPLED S IGNAL S PECTRUM
S AMPLED PULSES
H OW TO GET PAM SIGNAL
D IGITAL MODULATION Signal representation point of view Pulse code modulation Delta modulation Singal transmission point of view ASK FSK PSK
H OW TO GET PCM
D IGITAL MODULATION TECHNIQUES Delta modulation (DM) Linear delta modulation Adaptive delta modulation Block diagram of PCM Antialiasing filter Sampler QuantizerEncoder Analog signal x(t) Digital Signal
D ELTA MODULATION SYSTEM
D ELTA MODULATOR
A NOTHER KIND DELTA MODULATOR
D ELTA MODULATION DEMODULATOR
D ELTA MODULATED WAVEFORM
D IGITAL MODULATION (Transmission point of view)
F INALLY Representation of each pulse by 1/0 Pulse code modulation (PCM) Delta modulation Transmission of 1/0 ASK FSK PSK