On the effects of rotating blades on DS/SS communication systems
Yimin Daniel Zhang, Muhammad Amin, Vincent Mancuso · 2002
Direct-sequence spread-spectrum (DS/SS) techniques are widely used in military and commercial communication systems as well as in the global positioning system (GPS). We consider the Doppler effect of rotating blades in a helicopter on the DS/SS communications. We analyze the performance of DS/SS communications under such a multipath environment, by taking into consideration both Doppler fading and time delays. The model describing the effects of rotating blades on the desired signal is established, and the system performance is analyzed. It is shown that, for this specific application, the communication channel is not Rayleigh and does not resemble any of the commonly assumed fading models in wireless communications.