According to the
carrier phase error identification method based on decision feedback, the
carrier phase error is obtained through frequency multiplication and point selection, the
modulation order of a
signal after frequency multiplication is reduced, and the symbol decision frequency is preliminarily reduced; then, the
constellation diagram subjected to frequency multiplication is
clockwise rotated by 90 degrees,
constellation points located on the X axis are equivalent to multiple groups of
BPSK modulation with different amplitudes, therefore, the
constellation points located on the X axis are selected, extraction of
coherent integration and phase errors is facilitated, and the symbol judgment frequency can be further reduced. Compared with a conventional decision
feedback loop carrier phase error
discriminator, the rotation operation of the improved decision
feedback loop carrier
phase error discriminator does not bring extra calculation, and therefore, only multiplication operation brought by frequency multiplication is added, but the phase of a received
signal does not need to be extracted, and the judgment and
phase rotation on various modulation phases are not needed, so that the judgment times and the total calculation amount are greatly reduced.