Phase estimation method for short-interval sinusoidal signal and experimental device thereof

Abstract

The invention discloses a phase estimation method for a short-interval sinusoidal signal and an experimental device thereof. The CiR (cycles in record) of the tested sinusoidal signal is less than 1. The method comprises the following steps: sampling an inputted sinusoidal signal x(n)=Acos(2pif0+theta0) at an equal interval to obtain 2N-1 discrete sample sequences x(n); carrying out analytic transformation on the x(n) to obtain a complex sequence x1(n), and carrying out triangular window weighting and shift superposition to generate a sequence y(n) of which the length is N; computing the inner product of the sequence y(n) and a known sequence to obtain a complex value Q; and calculating the phase angle value of the complex value Q to obtain a phase measurement estimated value. The experimental device comprises a signal conditioning circuit, an A / D (analog-to-digital) conversion circuit, a digital signal processor (DSP), and an output drive and display unit. Compared with the prior art, the invention fills the gap of the short-interval sinusoidal wave phase estimation method within one cycle, has the advantages of high phase estimation precision, low computation quantity, high estimation efficiency and low resource consumption, and greatly saves hardware cost.

Description

technical field [0001] The invention belongs to the technical field of digital signal processing, and in particular relates to a digital measurement method for phase estimation of a sinusoidal signal whose observation interval is less than one period. Background technique [0002] Sinusoidal signal x(n)=Acos(2πf 0 +θ 0 )+B (or cosine signal, the difference is only in θ 0 A difference of 90°) is a common, simple and typical signal. Obviously, the characteristic of the sinusoidal signal is given by the frequency f 0 , amplitude A, phase θ 0 And the four parameters of DC component B to fully describe. Among them, DC component B is the easiest to measure, and can be estimated only by averaging the sampling points of all sinusoidal signals. Therefore, in order to simplify the measurement method, the influence of DC component B is not considered in the following description of the present invention. [0003] Usually, the sine signal is also called "sine wave". Obviously, the...

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Problems solved by technology

For example, the signal frequency in underwater submarine communication is often the "extremely low frequency" (Extremely low frequency, ELF) between 3 and 30 Hz, and because the observation time is limited, it is necessary to measure it within this short observation time The phase of the signal, its measurement accuracy will inevitably be affected by figure 2 Spectral leakage limit shown, making it difficult to estimate the distance of the enemy ship from our warship

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