How can I remove DC portion of the signal in SIMULINK?

[Luckybuilding]

remove dc signal

Hi all,
I need to remove DC( zero frequency) of a output signal of a model in MATLAB.

I have used simulink filters; but, it changes the signal shape that is not good for me because the filter is not ideal.

So, how can I remove DC portion of the signal not changing its original shape in MATLAB?


Thanks

 

[babaship]

remove dc from signal

check in matlab file exchange

 

[ridamsahu]

dc offset matlab

may be by adding the same amount of dc to the signal with apposite sign. but u need to calculate every time to add dc.

 

[Luckybuilding]

dc remove matlab

check in matlab file exchange

can you explain more?

thanks

Added after 9 minutes:

may be by adding the same amount of dc to the signal with apposite sign. but u need to calculate every time to add dc.

thanks for your suggestion. But, I want to use the results in a project that I can't use this way. Because, the supervisor of the project does not accept this way.

 

[ridamsahu]

remove dc offset from signal matlab

you can use bias block from simulink math block library. and provide the proper biasing value

 

[Btrend]

remove dc signal spice

to remove the DC component, u need a high-pass filter (HPF), and also u need to provide the HPF what's the cut-off freqency (ωc). Finally, ur input frequency to the HPF should be larger than ωc, otherwise the output signal shape of HPF will be changed.

 

[Luckybuilding]

offset simulink

to remove the DC component, u need a high-pass filter (HPF), and also u need to provide the HPF what's the cut-off freqency (ωc). Finally, ur input frequency to the HPF should be larger than ωc, otherwise the output signal shape of HPF will be changed.

Thanks for your reply
I have used this way and the signal's frequency is larger than the freq. But, the signal DC is not removed at first times of the signal and it is removed delayed and this changes the signal shape.

 

[Oldring]

remove offset simulink

To remove the DC offset you have:

1. to have to know the DC offset in some way;
2. to substract the DC offset from the signal.

The second step is trivial having the DC offset estimation. You just to add subtract block into your Simulink model subtracting the signal "DC offset" from your target signal. But to answer the question how to find the DC offset is not so easy. There are different situations with different answers. In general to find the correct solution a good understanding of your model is required together with estimation theory results.

The simplest situation if you know the DC offset a priori. In that case you just insert into your model a constant block generating the constant DC offset.

The more complex situation is if you do not know the DC offset before the signal processing start. In that case you have to calculate the offset from your signal. With some kind of LP filter for example. In some situations the DC offset is just the signal value before the processing signal wave arrival and can be latched before the signal waveform processing. Of course in general you can't calculate DC offset before the signal arrival. The standard solution is to delay you signal processing in some way for time sufficient for DC offset calculation - with discret delay block for example.

Hope this advice will help you to find the correct solution of your problem.