groupDelay

Group delay of digital down converter or digital up converter filter cascade

Syntax

D = groupDelay(Conv,N)

[D,F] = groupDelay(Conv,N)

Description

D = groupDelay(Conv,N) returns a vector of group delays, D, of a digital down converter or digital up converter, Conv, evaluated at N frequency points. The frequency points are equally spaced around the upper half of the unit circle.

[D,F] = groupDelay(Conv,N) returns a vector of frequencies, F, at which the group delay has been computed.

Examples

Group Delays of Digital Down Converter

Compute the group delays of the digital down converter using the groupDelay function.

Create a dsp.DigitalDownConverter System object with the default settings.

dwnConv = dsp.DigitalDownConverter

dwnConv = 
  dsp.DigitalDownConverter with properties:

           DecimationFactor: 100
         MinimumOrderDesign: true
                  Bandwidth: 200000
    StopbandFrequencySource: 'Auto'
             PassbandRipple: 0.1000
        StopbandAttenuation: 60
                 Oscillator: 'Sine wave'
            CenterFrequency: 14000000
                 SampleRate: 30000000

  Use get to show all properties

Use the groupDelay function to compute the vector of group delays. By default, the function evaluates the group delays at 8192 frequency points equally spaced around the upper half of the unit circle.

D = groupDelay(dwnConv);

Plot the vector of group delays.

plot(D)
xlabel('Number of frequency points')
ylabel('Group delay')

Determine the vector of frequencies over which the group delays are computed and plot them.

[D,F] = groupDelay(dwnConv);
plot(F,D)
xlabel('Frequencies')
ylabel('Group delay')

Input Arguments

Conv — Digital down converter or digital up converter

dsp.DigitalDownConverter | dsp.DigitalUpConverter

Digital down converter or digital up converter, specified as a dsp.DigitalDownConverter or dsp.DigitalUpConverter System object™.

N — Number of frequency points

8192 (default) | positive scalar

Number of frequency points over which the group delays are evaluated, specified as a positive scalar. These points are equally spaced around the upper half of the unit circle.

Data Types: double | single

Output Arguments

D — Vector of group delays

column vector

Vector of group delays of the digital down converter or digital up converter, evaluated at N frequency points equally spaced around the upper half of the unit circle.

Data Types: double

F — Vector of frequencies

column vector

Frequencies at which the group delays are evaluated, returned as a column vector.

Data Types: double

Version History

Introduced in R2012a