High-Precision Fourth Power Carrier Phase Recovery Algorithm
In coherent optical communication systems, phase noise of the laser causes the signal to rotate in the complex plane; therefore, the estimation and recovery of carrier phase are required at the receiving end. Herein, when using the M-th power carrier phase recovery algorithm to estimate the phase, we simplify the summing and averaging of adjacent N symbols to reduce the influence of additive Gaussian noise. The proposed algorithm considers the phase shift caused by the residual frequency offset, phase noise, and additive Gaussian noise together. Then, the algorithm estimates the total phase shift caused by these three factors and resumes the modulation phase. The performance of the proposed algorithm is compared with that of the traditional M-th power carrier phase recovery algorithm in the simulation. After the phase recovery by the proposed algorithm, the error between the signal and original modulation phases is only 10 -16 rad. However, when using the traditional algorithm, the error can reach 0.3 rad, implying that the proposed algorithm can recover the modulation phase more accurately and has a higher estimation accuracy. In the simulation, even without compensating for the frequency offset, phase recovery can be realized using the proposed algorithm, while the traditional algorithm can only recover the phase of the signal after compensating the frequency offset. In addition, the complexity of the algorithm is reduced by reducing the summing and averaging step as well.
邱琪：电子科技大学光电科学与工程学院, 四川 成都 610054
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Jie Zhang, Qi Qiu. High-Precision Fourth Power Carrier Phase Recovery Algorithm[J]. Laser & Optoelectronics Progress, 2019, 56(13): 130604
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