A digital demodulator based on the recursive Gauss-Newton method for electrical tomography

In the paper, a digital demodulator based on the recursive Gauss-Newton method is proposed for Electrical Tomography. The digital demodulator can track the amplitude and phase of a noisy sinusoidal signal with known frequency directly. Compared with the traditional digital multiplication demodulation method, the proposed demodulator is more flexible. It is implemented in a recursive way and only part of a full period is required for demodulation. Therefore, the trade-off between the speed and precision can be made by using the proposed demodulator. The proposed demodulator was implemented in the software and possessed low computational complexity. Numerical simulation was carried out to prove its feasibility. The parameters in the demodulator were optimized.