# dsp.DigitalUpConverter

Interpolate digital signal and translate it from baseband to IF band

## Description

The `dsp.DigitalUpConverter`

System object™ interpolates a digital signal, and translates it from baseband to intermediate
frequency (IF) band.

To digitally upconvert the input signal:

Create the

`dsp.DigitalUpConverter`

object and set its properties.Call the object with arguments, as if it were a function.

To learn more about how System objects work, see What Are System Objects?

## Creation

### Description

returns a
digital up-converter (DUC) System object, `upConv`

= dsp.DigitalUpConverter`upConv`

.

returns a DUC System object with the specified property `upConv`

= dsp.DigitalUpConverter(`Name,Value`

)`Name`

set to the specified
value `Value`

. You can specify one or more name-value pair arguments in
any order as
(`Name1`

,`Value1`

,...,`NameN`

,`ValueN`

).
Enclose each property name in single quotes. For example, create an object that upsamples
the input signal by a factor of 20, using a filter with the specified
qualities.

upConv = dsp.DigitalUpConverter('InterpolationFactor',20,... 'SampleRate',Fs,... 'Bandwidth',2e3,... 'StopbandAttenuation',55,... 'PassbandRipple',0.2,... 'CenterFrequency',50e3);

## Properties

## Usage

### Syntax

### Description

### Input Arguments

### Output Arguments

## Object Functions

To use an object function, specify the
System object as the first input argument. For
example, to release system resources of a System object named `obj`

, use
this syntax:

release(obj)

## Examples

## More About

## Algorithms

The digital up converter upsamples the input signal using a cascade of three interpolation filters. This algorithm frequency-upconverts the upsampled signal by multiplying it with a complex exponential that has the specified center frequency. In this case, the filter cascade consists of an FIR interpolation stage, a second stage for CIC compensation, and a CIC interpolator. The block diagram shows the architecture of the digital up converter.

The scaling section normalizes the CIC gain and the oscillator power. It can also contain a
correction factor to achieve the desired ripple specification. Depending on how you
set the interpolation factor, the block bypasses the first filter stage. When the
input data type is floating point, the algorithm implements an
*N*-section CIC interpolation filter as a FIR filter with a
response that corresponds to a cascade of *N* boxcar filters. The
algorithm emulates a CIC filter with an FIR filter so that you can run simulations
with floating-point data. When the input data type is a fixed-point type, the
algorithm implements a true CIC filter with actual comb and integrator
sections.

This block diagram represents the DUC arithmetic with floating-point inputs.

For details about fixed-point operation, see Fixed Point.

## Extended Capabilities

## Version History

**Introduced in R2012a**

## See Also

### Functions

`getDecimationFactors`

|`getFilterOrders`

|`getFilters`

|`fvtool`

|`groupDelay`

|`visualizeFilterStages`

|`generatehdl`