LTPDA Toolbox™ | contents |
Upsampling is the process of increasing the sampling rate of a signal. Upsample increases the sampling rate of the input AOs by an integer factor. LTPDA upsample overloads upsample function from Matlab Signal Processing Toolbox. This function increases the sampling rate of a signal by inserting (n-1) zeros between samples. The upsampled output has (n*input) samples. In addition, an initial phase can be specified and, thus, a delayed output of the input can be obtained by using this option.
b = upsample(a, pl)
The following parameters can be set in this method:
1. Upsampling a sequence of random data at original sampling rate of 1 Hz by a factor of 10 with no initial phase.
pl = plist('tsfcn', 'randn(size(t))','fs',1,'yunits','m','nsecs',100); x = ao(pl); pl_up = plist('N', 10); % increase the sampling frequency by a factor of 10 y = upsample(x, pl_up); % resample the input AO (x) to obtain the upsampled AO (y) iplot(x, y)
2. Upsampling a sequence of random data at original sampling rate of 1 Hz by a factor of 21 with a phase of 20 samples.
pl = plist('tsfcn', 'randn(size(t))','fs',1,'yunits','m','nsecs',100); x = ao(pl); pl_upphase = plist('N', 21,'phase', 20); % increase the sampling frequency and add phase of 20 samples to upsampled data y = upsample(x, pl_upphase); % resample the input AO (x) to obtain the upsampled and delayed AO (y) iplot(x, y)
Downsampling data | Resampling data |
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