International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / The Bit Error Rate (BER) performance of FQPSK modulated signals in the presence of the Co-Channel
Interference (CCI) and Additive White Gaussian Noise (AWGN) is evaluated and improved. A Non-
Linearly Amplified (NLA) FQPSK modulated signal with the data rate of 1Mb/s and carrier frequency
of 70 MHz is interfered with a sinusoidal signal at different frequencies. As the relative distance of the
center frequency of the Co-channel interference (CCI) changes, different BER are obtained. The effect
of the CCI decreases as the CCI center frequency moves away from the center of the modulated signal.
In order to improve the BER in the presence of the CCI, a hard limited filter is added at the receiver
input. The hard limited filter has a different amplification factor for different signal strength. As a result,
the amplification factor for the CCI, which is normally a weaker signal, is smaller than the actual signal.
This means that the signal is amplified more than the interference and as a result the CCI is suppressed
and the BER rate improves. The results of both simulations and measurements are obtained for different
CCI center frequencies, before and after the improvements.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/606773 |
| Date | 10 1900 |
| Creators | Haghdad, Mehdi, Feher, Kamilo |
| Contributors | University of California, Digcom Inc. |
| Publisher | International Foundation for Telemetering |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Proceedings |
| Rights | Copyright © International Foundation for Telemetering |
| Relation | http://www.telemetry.org/ |
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