| 摘要 |
PURPOSE:To attain correct phase comparison even when a reception signal is deteriorated and to recover a stable carrier even at the normal state by devising the device such that a phase of an input signal is rotated on a phase plane by npi/4 (n=1,3,5,7) so as to detect a phase error. CONSTITUTION:A phase shifter 3-5 receives an output of an in-phase channel identification device 3-3 and an output of an orthogonal channel identification device 3-4 and rotates the phase on the phase plane by npi/4 (n=1,3,5,7). A phase comparator 3-6 receives an output of the phase shifter 3-5, extracts a signal point in excess of a level of a prescribed range in in-phase and orthogonal channels, discriminates whether the position of the phase plane of the signal point is in a range easily in existence when the phase of the recovered carrier is led than the position of a reception signal or in a range easily in existence when the phase of the recovered carrier is lagged than the position of the reception signal so as to detect whether the phase of the reception signal is led or lagged to the phase of the recovered carrier, an integration device 3-7 integrates the error and its integration value controls the oscillating frequency of a voltage controlled oscillator 3-9. |
