02-10-2008 09:02 PM
Thank you for using our product. I have read your VI. You might need to modify your codes at following several places
For the adaptive filtering part,
1. You can't just provide one point of data for adaptive filtering VIs.
2. For noise cancellation applications, the noisy singal is connected to d(n), the noise reference signal is connected to x(n), the error signal is the filtered signal.
For signal genreation part.
1. You might use Sound File Read Simple.vi to read .wav file.
2. The output data type of noise_ref should be array.
3. I also modified the noise generationscripts. You should provide the noise before FIR filtering as the noise reference.
I am not sure whether you are using LabVIEW 8.5. So I just attached the screenshot of revised VI for you. Feel free to let me know if you have any more questions.
02-18-2008 01:39 PM
Hi Kevin Wang, thank you for Adaptive filter
Can you please check this? My application is noise cancellation using FIR LMS algorithm.
i want output signal a same input signal. How i modify it ?
02-29-2008 12:46 AM
I have following suggestions for your simulation example.
1. You should not directly connect the noise to x(n). Actually if you can directly acquire the noise, you can just subtract it from noisy signal. You don't need the adaptive filter anymore. You need to provide the noise reference for adaptive filter. You can refer to my attachment for more info.
2. The adaptive filtering will just help you to improve the signal to noise ratio. In other words, the SNR of filtered signal will be better than that of noisy signal. And the filtered signal will never be exactly as same as the original signal.
Since I am not sure the version of LabVIEW you use. I just attach the screenshot of my revision for you. You can easily modify your example with it.
Feel free to let me know if you have any more questions.
02-29-2008 03:00 PM
Hi Kevin Wang,
Thank you for Adaptive filter noise.jpg
Can you please check this?
i want measure SNR output signal and SNR input signal, and to compute Mean SNR in 100. How i modify it ?
i modify it but it is not correct , Show VI attachment, Should i modify it?
04-11-2008 12:57 PM
04-16-2008 11:43 AM
Excellent Job! I can't believe that this toolkit only use 3 polymorphic VI's which are used for the adaptive filter design . Especily ,the examples are very good: Learning Curve PrintLearning Curve Print can be used for SI, Adaptive Notch Filters can be used for "multi-source noise" cancellation, Adaptive Noise Cancellation can be used for engineer applicatipn after simply modification.
I find the that ADF FIR LMS Filtering (Multi Channel PtByPt).vi used in Adaptive Notch Filters is not added(packed) into the ADF Filtering.vi(polymorphic VI).
04-16-2008 12:01 PM