Digital realization method for sine wave signal

Abstract

The invention relates to a digital realization method for a sine wave signal. The method specifically comprises the steps of firstly setting parameters and calculating a sampling point number N in a sine wave signal period and an angle value theta occupied by one sampling point; secondly calculating numerical values of sin(theta) and cos(theta) as well as sin(2theta) and cos(2theta); thirdly calculating a discrete point numerical value f0 of the sine wave signal; fourthly transmitting the discrete point numerical value f0 of the sine wave signal into a DAC conversion circuit to generate a continuous sine wave current signal; and finally converting the continuous sine wave current signal into a continuous sine wave voltage signal by utilizing a UA operational amplifier so as to realize output of the sine wave signal. According to the digital realization method for the sine wave signal, a calculation program is simplified and calculation time of a DSP controller is shortened; an accumulative error caused by continuous recursive calculation is effectively reduced, the occupied storage space is small, and the cost is low; and initial sine function value and cosine function value can be conveniently calculated and the frequency of the sine wave signal can be flexibly adjusted.

Description

technical field [0001] The invention belongs to the field of realization of wave signals, in particular to a digital realization method of sine wave signals. Background technique [0002] Sine wave signal generators have been widely used in signal processing systems in the fields of communication, instrumentation, and industrial control. There are many digital implementation methods for generating sine wave signals based on DSP controller, the difference mainly lies in the difference of generation algorithm and software. There are three commonly used methods: look-up table method, Taylor series expansion method and iteration method. [0003] The look-up table method is the most direct digital implementation method. The designer can pre-calculate all possible sine function values ​​according to the needs of the operation, and arrange these results into a data table. The function value of . The table look-up method is characterized by fast speed and easy frequency and ampli...

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Problems solved by technology

However, since the new value is generated using the previous function value, there will be cumulative error, especially in the second half of the sine wave, the cumulative error will become larger and larger, and when the number of sampling points N is not large enough, the cumulative error will be will further increase

At the same time, since the values ​​of sin(θ) and cos(θ) must be preset before the calculation of the recursive formula, the number of sampling points N cannot be changed. At the sampling frequency f s In the case of fixed, it affects the flexible adjustment of the frequency f of the sine wave

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