FCC Exam Question: 3-78L2
Which of the following answers is true?
Explanation: CDMA (Code Division Multiple Access) signals utilize complex digital modulation that results in a high peak-to-average power ratio (PAPR). This means the instantaneous power of the signal fluctuates rapidly and significantly above its average power. Analog power meters are typically designed and calibrated for measuring the average power of continuous wave (CW) or relatively stable signals like FM. They struggle to accurately respond to and integrate the fast-changing, high-peak characteristics of a complex digital signal like CDMA, leading to an inaccurate reading. Specialized digital or true RMS power meters are required for accurate measurements of such dynamic signals. Therefore, statement A is incorrect because analog meters are not accurate for CDMA. Statement C is also incorrect because power *can* be measured using CDMA modulation, but it requires appropriate test equipment, not a simple analog power meter.
3-7A3
3-41F6
3-23C4
3-54G1
3-21C1
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Includes Elements 1, 3, 6, 7R, 8, and 9.