Performance Comparison of Bipolar Alternate Mark Inversion and Conditioned Diphase Waveforms Over Wireline Media
Final rept. Oct 75-Apr 76,
ROME AIR DEVELOPMENT CENTER GRIFFISS AFB NY
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This report was prepared for the Defense Communications Agency to study the performance of two waveforms competing for implementation in the Defense Communications System. The waveforms, Bipolar Alternate Mark Inversion BAMI and Conditioned Diphase CDtheta, were studied both from a theoretical standpoint and with experimental breadboard hardware designed and built in- house. Theoretical performance curves for both waveforms operating in wideband gaussian noise were developed and the hardware was tested against wideband gaussian noise. The results of testing the waveform over Griffiss AFB cable plant are presented along with computer-generated distributions of data bit errors encountered. The effects and problems involved in recovering timing information from two waveforms are not covered in this report. The results indicate that, with white gaussian noise as the only transmission impairment, the two waveforms perform nearly identically. Their performances are also close when operation is over cables with moderate amounts of intersymbol interference and attenuation. However, when intersymbol interference and attenuation are severe long calbes, high data rates, and poor-condition cables, BAMI has an advantage of approximately 30 percent, expressed in terms of maximum usable bit rate for a given length of cable. Another conclusion reached was that impulse noise is the limiting impairment of the Griffiss AFB cable plant.
- Non-Radio Communications