| 摘要 |
PURPOSE:To realize frequency error detection stably and inexpensively with high sensitivity based on a phase amplitude modulation wave in a frequency discriminating system. CONSTITUTION:The system is provided with a coordinate degeneration transformation section 1 in which orthogonal 2-series digital signals I, Q based on a phase amplitude modulation wave signal are converted into a loopback binary number, a high-order bit used for identifying a quadrant on a phase plane and each code point area is eliminated to be degenerated into a unit area and with a polar coordinate transformation section 2 applying polar coordinate transformation to degenerated orthogonal 2-series digital signals I', Q' in the unit area and discriminates a frequency based on the phase angle subjected to polar coordinate transformation. The frequency is preferably discriminated by comparing the phase angles subjected to polar coordinate transformation in time series. Furthermore, the frequency is discriminated preferably by comparing the phase angle subjected to polar coordinate transformation with a phase angle at a code point. |
