This web-based tool calculates dmin for a given CPM scheme and returns a MLSD/MLSE performance bound.
To specify a particular CPM scheme, you need to give three parameters:
the data alphabet (binary, 4-ary, etc.),
the modulation index(es) (single-h CPM has just one modulation index, multi-h CPM has more than one), and
the length and shape of the frequency pulse.
1. Data Alphabet
We will assume the data alphabet size is an integer power of two, i.e. M = 2^m, so all you need to specify is the exponent m
(1 for binary, 2 for 4-ary, etc.)
m = (an integer from 1 to 3)
Also, the probability of error (but not the minimum distance) is a function of the mapping from bits to
symbols. Select one of the following:
Natural map
Gray code
2. Modulation Indexes
We will assume that the modulation indexes are rational numbers, i.e. h=k/p.
For single-h CPM, specify one integer value for the
numerator k and one integer value for the denominator p.
For multi-h CPM, specify multiple integer values for the numerator,
separated by commas, and one integer value for the common denominator p.
k = (an integer between 1 and 100)
p = (an integer between 1 and 100)
3. Frequency Pulse
The frequency pulse has a finite duration of L symbol times, where L is an integer.
L = (an integer between 1 and 10)
There are many possible shapes for the frequency pulse. You can choose from the common ones
listed below, or you can upload a text file with a custom pulse shape of your own.
Rectangular (REC)
Raised cosine (RC)
Gaussian, with parameter
B =
Custom pulse shape.
The custom pulse shape must be contained in an ASCII text file, with one sample per line.
The pulse must be sampled at N samples per symbol, where N is
the integer you indicate below. This means that
the file must have L*N lines of text, with one number per line.
Your file can have comments if desired,
where % is the comment character and must be the first character in the comment line. Don't worry about
normalizing the area of the pulse, I'll take care of that.
Custom pulse file:
N =
[If you leave these input fields empty, then the previous custom pulse shape, found
here, will be used.]
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