rectpulse

Rectangular pulse shaping

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Syntax

Y = rectpulse(X,nsamp)

Description

Y = rectpulse(X,nsamp) performs rectangular pulse shaping on X and returns Y, increasing the sample rate of X by repeating each sample nsamp times.

example

Examples

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Open Live Script

Create an array of modulated symbols. The first channel (column) contains QPSK-modulated symbols. The second channel contains 16QAM-modulated symbols.

M_psk = 4;   % PSK modulation order
M_qam = 16;  % QAM modulation order
nsymb = 10;  % Number of modulated symbols

ch1 = pskmod(randi([0 M_psk - 1],nsymb,1),M_psk,pi/4);
ch2 = qammod(randi([0 M_qam - 1],nsymb,1),M_qam);
X = [ch1 ch2];

Plot the real and imaginary parts of the modulated symbols.

figure
subplot(2,1,1)
stem(real(X))
grid on
xlabel('Symbols')
ylabel('\Re(X)')
subplot(2,1,2)
stem(imag(X))
grid on
xlabel('Symbols')
ylabel('\Im(X)')

Figure contains 2 axes objects. Axes object 1 with xlabel Symbols, ylabel \Re(X) contains 2 objects of type stem. Axes object 2 with xlabel Symbols, ylabel \Im(X) contains 2 objects of type stem.

Set the number of samples per symbol.

nsamp = 4;

Perform rectangular pulse shaping and display the result.

Y = rectpulse(X,nsamp);
figure
subplot(2,1,1)
plot(real(Y),'-') 
grid on
xlabel('Samples')
ylabel('\Re(y)')
ylim([-3.5 3.5])
subplot(2,1,2)
plot(imag(Y),'-')
grid on
xlabel('Samples')
ylabel('\Im(Y)')
ylim([-3.5 3.5])

Figure contains 2 axes objects. Axes object 1 with xlabel Samples, ylabel \Re(y) contains 2 objects of type line. Axes object 2 with xlabel Samples, ylabel \Im(Y) contains 2 objects of type line.

Input Arguments

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Input symbols, specified as a vector or matrix. If X is a matrix with multiple rows, the function treats the columns as independent channels.

Data Types: double | single
Complex Number Support: Yes

Number of samples per symbol, specified as a positive integer.

Data Types: double | single

Output Arguments

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Output samples, returned as a vector or matrix.

  • If the input X is a vector, the output is an L-element vector consisting of each sample in X repeated nsamp times, where L is length(X)*nsamp.

  • If the input X is a matrix, the function processes each column as an independent channel and the output is an L-by-M matrix, where L is size(X,1)*nsamp and M is size(X,2).

The data type is the same as that of X.

Extended Capabilities

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C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced before R2006a

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See Also

Functions

Blocks

Topics