Develop threshold for an analog signal

[cincidude]

Hi,

I am looking to develop a threshold condition (upper and lower boundary) for an analog signal.

Say I have an analog signal and I want to develop an offet around the signal. The trick is not only to add and subtract an offset of a fixed magnitude around each data point, but for each of the threshold signals (upper and lower), the slope of the line joining two successive points should be the same.

Also, the analog signals obtained for the positive and negative threshold should have the same number of data points as the original analog signal.

Thanks,
-Dude

 

[IRstuff]

based on what criteria? Pfa, Pd?

You can certainly do a running calculation of rms deviation.

TTFN

 

[cincidude]

OK, I apologize that I am not really aware of the technical terms (Pfa, Pd). Neither am I aware how to calculate RMS deviation. Could you please explain.

Thanks,
-Dude

 

[IRstuff]

Pfa -- probability of false alarm
Pd -- probability of detection
RMS -- look in your statistics or math book

TTFN

 

[VisiGoth]

nData = 100;
dataAnalogSampled = randn( 1, nData );
thresholdHigh = dataAnalogSampled + 1;
thresholdLow = dataAnalogSampled - 1;

But this seems like a meaningless excersize, changing the threshold point by point once ou know the point. What am I missing?