Signal Processing Toolbox

upsample

Increase the sampling rate of the input signal

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