Carrier phase recovery method and system based on Q-power polarity judgment

Abstract

The invention discloses a carrier phase recovery method and system based on Q-power polarity judgment, and the method comprises the steps: carrying out the Q-power operation and phase rotation of a received signal after phase compensation, and then carrying out the power detection; selecting a signal with relatively high power after rotation to carry out polarity judgment, thereby calculating a phase offset signal; calculating a phase compensation signal of the received signal at the next moment according to the phase offset signal, and performing phase compensation on the received signal at the next moment by using the phase compensation signal. Compared with a Q-power-based polar ring, the method has the advantages that the frequency offset capture range is widened, and the noise immunity is improved; compared with a PD algorithm, the method is suitable for QPSK, 8PSK, 16APSK and other amplitude modulation modes; and compared with a DD algorithm, the frequency offset capture range isimproved.

Description

Technical field[0001]The present invention relates to the field of digital communication technologies, and more particularly to a carrier phase recovery method and system based on Q sub-polarity decision.Background technique[0002]When the digital communication receiver uses a coherent demodulation, the receiving end needs to provide a coherent carrier that is the same as the same phase of the transmitter. However, during the transmission process, the carrier output of the digital lower frequency conversion output due to the various causes of the system vibration frequency error and Doppler effect, thereby causing rotation and jitter of the received signal. Therefore, it is necessary to use a carrier recovery technique to correct the frequency offset and meticulousness between the receiving end carrier and the transmitting carrier. Carrier recovery can be divided into two portions of carrier frequency recovery and carrier phase recovery. The signal is still existed after the carrier ...

AI Technical Summary

Problems solved by technology

Among them, the DD algorithm adopts full constellation judgment, which can effectively eliminate additive noise and has good steady-state tracking ability, but the frequency offset capture ability is small, usually less than 10KHz

In order to further improve the ability of frequency offset capture, a PD algorithm with a power detection module is proposed, but this algorithm does not work well for QPSK, 8PSK, 16APSK and other amplitude modulation signals

The polarity ring based on the Q power is to process the signal to the Q power, so that the signal constellation is converged, and then the judgment is made, which simplifies the time of the algorithm and increases the reliability. However, it is seriously affected by noise, which reduces the efficiency of the algorithm. Phase offset recovery performance

Therefore, in order to make the carrier phase recovery algorithm not only capture large frequency offsets, but also perform stable tracking and have high phase offset recovery performance, in 2016, Wu Fenghui proposed the DD algorithm and the phase frequency detection (PFD) algorithm. Combined carrier phase recovery algorithm, but this algorithm needs to add a mode conversion algorithm to ensure the correct switching of the two algorithms, which will increase the complexity of the algorithm

In the same year, Zhu Shibing proposed a carrier phase recovery algorithm based on the combination of the Q power polar loop and the DD algorithm. This algorithm also requires mode switching, which increases the complexity of the algorithm.

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