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Probability of relative power value using CCDF



P = getProbability(ccdf,R) returns the probability, as a percentage in the range [0, 100], that the power level of a signal is above its average power by the specified level R. The input ccdf specifies the complementary cumulative distribution function (CCDF) curves of the signal of interest. For the ith channel in the input signal, the function evaluates the corresponding CCDF curve at relative power value R(i).

Before calling the getProbability function, you must obtain the CCDF curves of the signal of interest by calling the ccdf System object™ on the signal.


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Generate a unit variance AWGN signal and a dual-tone signal.

n = [0:5e3-1].';
s1 = randn(5e3,1);                    % AWGN signal
s2 = sin(0.01*pi*n) + sin(0.03*pi*n); % Dual-tone signal

Create a CCDF measurement object.

ccdf = comm.CCDF;

Obtain the CCDF curves of the signals.

ccdf([s1 s2]);

Plot the resulting CCDF curves.


Figure contains an axes object. The axes object with title CCDF Measurement contains 2 objects of type line. These objects represent AWGN, Dual-tone.

Find the probability that the AWGN signal power is 5 dB above its average power and the probability that the dual-tone signal power is 3 dB above its average power.

P = getProbability(ccdf,[5 3])
P = 2×1


Input Arguments

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CCDF measurements, specified as a comm.CCDF System object. The object must contain CCDF curves. To obtain CCDF curves, call the object on the input signal of interest.

Relative power value, specified as one of these options.

  • Numeric scalar — The function evaluates each CCDF curve at the relative power value R.

  • Numeric row vector — The function evaluates the ith CCDF curve in the input ccdf at relative power value R(i).

The ccdf.PowerUnits property specifies whether the relative power value is returned in a dB scale or linear scale.

Data Types: double

Output Arguments

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CCDF probability of the relative power value, returned as a numeric column vector with values in the range [0, 100]. A value of 100 corresponds to a probability of 1.0. P(i)/100 is the probability value of the channel corresponding to the ith CCDF curve in the input ccdf.

Data Types: double

See Also



Introduced in R2012a