pamdemod

Pulse amplitude demodulation

Syntax

z = pamdemod(y,M)
z = pamdemod(y,M,ini_phase)
z = pamdemod(y,M,ini_phase,symbol_order)

Description

z = pamdemod(y,M) demodulates the complex envelope y of a pulse amplitude modulated signal. M is the alphabet size. The ideal modulated signal should have a minimum Euclidean distance of 2.

z = pamdemod(y,M,ini_phase) specifies the initial phase of the modulated signal in radians.

z = pamdemod(y,M,ini_phase,symbol_order) specifies how the function assigns binary words to corresponding integers. If symbol_order is set to 'bin' (default), the function uses a natural binary-coded ordering. If symbol_order is set to 'gray', it uses a Gray-coded ordering.

Examples

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Demodulate PAM Signal

Modulate and demodulate random integers using pulse amplitude modulation. Verify that the output data matches the original data.

Set the modulation order and generate 100 M-ary data symbols.

M = 12;
dataIn = randi([0 M-1],100,1);

Perform modulation and demodulation operations.

modData = pammod(dataIn,M);
dataOut = pamdemod(modData,M);

Compare the first five symbols.

[dataIn(1:5) dataOut(1:5)]
ans =

     9     9
    10    10
     1     1
    10    10
     7     7

Verify that there are no symbol errors in the entire sequence.

symErrors = symerr(dataIn,dataOut)
symErrors =

     0

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