WWVB Transceiver Simulator

Rabih Saliba, Wael Barakat, and Brian L. Evans
Embedded Signal Processing Laboratory
Department of Electrical and Computer Engineering
The University of Texas at Austin, Austin, TX 78712-1084

06/14/08

This software uses LabVIEW to simulate a WWVB transceiver. This first release only simulates the physical layer where a WWVB signal will be generated and decoded into the corresponding bits that contain the time information. To get a WWVB signal, we simuated a transmitter that takes random bits and generates a WWVB signal. The simulation is in National Instruments LabVIEW software.

A paper describing WWVB signals and their use in Wireless Sensor Networks for the purpose of synchronization at the application layer "Application Layer Synchronization in Wireless Sensor Networks Using WWVB" is available in pdf format.

Download

WWVB Simulator 1.0, June 13, 2008. This release simulates a WWVB transceiver where a transmitter is responsible for generating a WWVB signal that will be sent over a channel to a receiver where proper bits will be decoded. A channel model is not yet implemented and an ideal channel model is used.
This release can be run without LabVIEW. To run it in LabVIEW, you will need
- LabVIEW 8.2 or higher
Please see Directions to Run the Simulations below.
Caveats about version 1.0:
- The channel used is an ideal wire that does not approximate a real channel.
- The drop in power in the ASK modulated signal is assumed to go to zero .
- The physical layer is only implemented where the output is in bit format. Decoding the content of those bits gives the actual time.

Directions to Run the Simulator

Two options to run the simulator:

To run the simulation within LabVIEW, you will need to have version 8.2 (or higher) of LabVIEW. After you download and unzip the above release, start LabVIEW. Then, open WWVB_System.vi in the LabVIEW sub-directory of the release. Finally, run the virtual instrument (VI) by choosing Operate...Run, hitting Ctrl-R, or hitting the right arrow icon in the upper left part of the demo window.
To run the simulation without LabVIEW, you'll need to download and install the freely distributable LabVIEW Run-time Engine Version 8.2.1 for Windows/2000/Vista x64/Vista x86/XP .

Acknowledgments

We would like to thank Mr. Shawn McCaslin at National Instruments for the idea of using WWVB in synchronizing Wireless Sensor Networks.

References

M. A. Lombardi, “NIST time and frequency services,” NIST, Special Publication 432, Jan. 2002.
G. Nelson, M. Lombardi, and D. Okayama, “NIST time and frequency radio stations: WWV, WWVH, and WWVB,” NIST, Special Publication 250-67, Jan. 2005.
B. Sundararaman, U. Buy, and A. D. Kshemkalyani, “Clock synchronization for wireless sensor networks: a survey,” Ad Hoc Networks, vol. 3, no. 3, pp. 281–323, 2005.
S. Rhee, D. Seetharam, and S. Liu, “Techniques for minimizing power consumption in low data-rate wireless sensor networks,” in Wireless Communications and Networking Conference, 2004. WCNC. 2004 IEEE, vol. 3, Mar. 2004, pp. 1727–1731.
G. Systems, “EM2S WWVB receiver technical sheet,” Dec. 2007.

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