upsample (Signal Processing Toolbox)

Increase sampling rate by integer factor

Syntax

y = upsample(x,n)
y = upsample(x,n,phase)

Description

y = upsample(x,n) increases the sampling rate of x by inserting n-1 zeros between samples. x can be a vector or a matrix. If x is a matrix, each column is considered a separate sequence. The upsampled y has x*n samples.

y = upsample(x,n,phase) specifies the number of samples by which to offset the upsampled sequence. phase must be an integer from 0 to n-1.

Examples

Increase the sampling rate of a sequence by 3:

x = [1 2 3 4];
y = upsample(x,3);
x,y
x =
    1    2    3    4
y =
    1    0    0    2    0    0    3    0    0    4    0    0

Increase the sampling rate of the sequence by 3 and add a phase offset of 2:

x = [1 2 3 4];
y = upsample(x,3,2);
x,y
x =
    1    2    3    4
y =
    0    0    1    0    0    2    0    0    3    0    0    4

Increase the sampling rate of a matrix by 3:

x = [1 2; 3 4; 5 6;];
y = upsample(x,3);
x,y
x =
    1    2
    3    4
    5    6
y = 
    1    2
    0    0
    0    0
    3    4
    0    0
    0    0
    5    6
    0    0
    0    0

See Also

decimate, downsample, interp, interp1, resample, spline, upfirdn

upfirdn vco