Modulation recognition of spread spectrum signals using modulation domain measurements

The authors investigated the measurement and analysis of low-level spread spectrum signals without prior knowledge of the spreading code by using the modulation domain measurement technique. Signals were processed and measured with the HP 5372A modulation domain analyzer. Pseudorandom events can be captured and analyzed. The analysis includes the average carrier frequency, the relative phase, the hop/agile frequencies, and the amplitude with accurate time resolution. Eye patterns can be easily displayed. Software algorithms and hardware that allow this analysis with a 500-MHz signal bandwidth for signals up to 3 GHz are described. A theoretical review is followed by examples of the measurements.<
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