An improved phase generated carrier demodulation algorithm with high stability and low harmonic distortion

In this paper, an improved phase generated carrier (PGC) demodulation algorithm is proposed to eliminate the influence of light intensity disturbance (LID) and reduce harmonic distortion at the same time. The algorithm is theoretically analyzed, numerically simulated, and experimentally verified. The performance of sensor using proposed algorithm is compared with sensor using traditional PGC-differential-cross-multiplying (PGC-DCM) algorithm and PGC algorithm proposed by predecessor, respectively. Experimental results show that the amplitude of the demodulation signal maintains at the true value, and harmonic distortion is well suppressed by the improved algorithm. In experiment, the signal to noise and distortion ratio (SINAD) of the improved algorithm is 28.62 dB, which is 21.2 dB and 5.5 dB higher than the traditional PGC-DCM algorithm and PGC algorithm proposed by predecessor, respectively.