S MandayamECE Dept Rowan University Digital Communications 0909

S. Mandayam/ECE Dept. /Rowan University Digital Communications 0909. 402. 03/0909. 504. 01 Fall 2002 Lecture 9 November 4, 2002 Shreekanth Mandayam ECE Department Rowan University http: //engineering. rowan. edu/~shreek/fall 02/digcomm/

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 Sampling Quantization Source Encoder ADC Data Encryption Encoder Error Control Encoder Channel/ Line Encoder Modulator Analog i/p CODEC MODEM Audio Amp Reconstruction/ DAC Source Decoder Data Encryption Decoder Error Control Decoder DEMUX Analog o/p Equalization / Decision Circuits Demodulator Multiple access channel Antialiasing Filter MUX Digital Communications Transceiver

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

S. Mandayam/ECE Dept. /Rowan University MSK

S. Mandayam/ECE Dept. /Rowan University I-Q Detector Balanced Modulator IF Signal Lowpass Filter x(t) Lowpass Filter y(t) Oscillator f. IF +p/2 Phase Shift Balanced Modulator

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

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

S. Mandayam/ECE Dept. /Rowan University Summary