Electrical Communications Systems 0909.331.01 Spring 2005

1
Electrical Communications Systems0909.331.01
Spring 2005
Lab 4 Pre-lab Instruction

• Shreekanth Mandayam
• ECE Department
• Rowan University
• http//engineering.rowan.edu/shreek/spring05/ecom
  ms/

2
Plan

• Digital Communications Transceiver
• PCM m-Law Quantization
• T1-Line TDM Protocol
• Lab Project 4

3
ECOMMS Topics
4
Digital Communications Transceiver
Anti- aliasing Filter
Data Encryption Encoder
Error Control Encoder
Channel/ Line Encoder
Source Encoder
Sampling
Quantization
Modulator
MUX
ADC
Analog i/p
CODEC
MODEM
Multiple access channel
Analog o/p
Data Encryption Decoder
Error Control Decoder
Audio Amp
Source Decoder
Reconstruction/ DAC
Equalization / Decision Circuits
Demod-ulator
DEMUX
5
T1-Line TDM Format
1 Frame (24 Channels F) 125 ms
F
193 bits
Frame Sync Bit Even Frames 0 0 1 1 1 0 Odd
Frames 1 0 1 0 1 0 Every Sixth Frame LSB (8th
bit) is a Signaling bit Bipolar R-Z Line Encoding
6
Lab Project 4Digital Baseband Communications
http//engineering.rowan.edu/shreek/spring05/ecom
ms/lab4.html
7
Test Circuit