S. Mandayam/ECE Dept./Rowan University Digital Communications / Fall 2002 Shreekanth Mandayam ECE Department Rowan University Lecture 9 November 4, 2002

S. Mandayam/ECE Dept./Rowan University Plan Bandpass Data Transmission MSK and GMSK Recall: Basic QAM Structure Coherent I-Q Detection Lab Project 2

S. Mandayam/ECE Dept./Rowan University Digital Communications Transceiver Anti- aliasing Filter SamplingQuantization Data Encryption Encoder Source Encoder Error Control Encoder Channel/ Line Encoder Modulator MUX Audio Amp Source Decoder Data Encryption Decoder Error Control Decoder Equalization / Decision Circuits Demod- ulator DEMUX Reconstruction/ DAC ADC CODEC MODEM Analog o/p Multiple access channel Analog i/p

S. Mandayam/ECE Dept./Rowan University Recall: Basic QAM Structure Matlab script: qpsk.m Binary Data -  /2 Phase Shift Transmitting Filter Balanced Modulator Transmitting Filter Balanced Modulator Oscillator f c  QAM Signal Serial- Parallel

S. Mandayam/ECE Dept./Rowan University MSK

I-Q Detector IF Signal +  /2 Phase Shift Balanced Modulator Balanced Modulator Oscillator f IF x(t) Lowpass Filter Lowpass Filter y(t)

S. Mandayam/ECE Dept./Rowan University Coherent QPSK Detection x(t) y(t) Integrate & Dump Threshold Device Parallel to Serial Conversion Integrate & Dump Threshold Device Bit sync m ~

S. Mandayam/ECE Dept./Rowan University Lab Project 2 Lab Project 2

S. Mandayam/ECE Dept./Rowan University Summary