ECE 445S Real-Time Digital Signal Processing Laboratory - Transmitter Demo

In the laboratory component, students design, implement in C, and test transceiver subsystems for voiceband data transmission on a digital signal processing board from Texas Instruments.

This following reference design and demonstration of a v22.bis baseband transmitter for a voiceband modem has two releases:

1. Zukang Shen and Lalo Perez, Version 1.1, August 28, 2008, for LabVIEW 8.5
2. Zukang Shen, Version 1.0 Beta 2, August 28, 2003, for LabVIEW 7.0

Download LabVIEW and run the TX.vi block diagram (virtual instrument) from one of the above releases. LabVIEW is backwardly compatible.

The transmitter demonstration offers interactive control of several of the transceiver parameters, including

• baud rate
• raised cosine rolloff for pulse shaping
• amount of channel noise

The LabVIEW demo is of a QAM transmitter and is entirely in discrete time. The demo

1. plots different visual views into the transmitter output (time-domain waveform, eye diagram, constellation points);
2. provides an interactive simulation that allows the user to change the noise power and other settings to see the effect on the different views of the transmitter output; and
3. has a block diagram of the transmitter that shows how each lab assignment will fit into the QAM transmitter application in lab 6.

The LabVIEW demonstration is based on the information in the following lab manual:

Steven A. Tretter, Communication System Design Using DSP Algorithms with Laboratory Experiments for the TMS320C6701 and TMS320C6711, Kluwer Academic/Plenum Press, ISBN 0-306-47429-8, March 2003. Corrections and code at http://www.ece.umd.edu/~tretter.

Last updated 06/07/22. Send comments to bevans@ece.utexas.edu