A fixed-point real-time noise reduction method based on DSP

Abstract

The invention relates to a fixed-point real time noise reduction method based on DSP, comprising steps of performing identification on a secondary channel through producing white noise, performing fixed-point processing on floating point arithmetic and using a loudspeaker to produce opposite noise to offset extraneous noise. The fixed-point real time noise reduction method based on DSP performs noise reduction processing by targeting single frequency noise and narrow band noise, achieves instantaneity on a C55x series DSP platform, performs fixed-point processing on the floating point arithmetic to greatly improve the operation speed on the DSP platform, performs noise reduction on high frequency noise with maximum frequency being 7khz through improving a sampling rate, adapts to possible change of the noise and has strong robustness.

Description

technical field [0001] The invention relates to a DSP-based fixed-point real-time noise reduction method for signal processing, audio processing and noise control. Background technique [0002] Today, with the rapid development of science and technology, people are also facing serious pollution problems while enjoying all kinds of convenience brought by modern science and technology. Among these pollutions, noise pollution is one of the pollution sources that directly endanger people's physical and mental health. Sound noise exists in various occasions, such as industrial production process, daily working environment, laboratory environment, etc., and it is even very serious in some occasions. These noises are detrimental to the staff who have been in close contact with the equipment for a long time, and have seriously harmed their physical and mental health, such as hearing loss, fatigue, decreased concentration, and reduced production efficiency. Therefore, as the noise b...

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Problems solved by technology

Although it can make the device simple, since the feedback structure needs error noise to drive, the residual noise after noise reduction cannot be completely eliminated【3】Tan L, JiangJ. Active noise control using the filtered-x rls algorithm with sequential updates[J]. Engineering Technology Opens the Door to a World of Opportunity, 2009:29. In the filter-x-least squares algorithm (FXRLS), the least squares criterion is added to the secondary channel compensation, and adaptive noise reduction is performed at the same time

This algorithm finds the global optimal solution and has a good noise reduction effect, but it has a large amount of calculation and cannot meet the real-time noise reduction requirements

【4】Amir N.Active acoustic noise reduction system: US, US 7317801B1.2008. In it, the feed-forward filter-X-least mean square algorithm (FXLMS) is adopted, and the DSP-based dual microphone platform is used, which has a relatively low-frequency noise Good noise reduction effect, but since the highest sampling rate is only 4k, it cannot perform noise reduction on high frequency noise

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