# dsphdl.Channelizer

Polyphase filter bank and fast Fourier transform

## Description

The `dsphdl.Channelizer`

System object™ separates a broadband input signal into multiple narrowband output signals. It
provides hardware speed and area optimization for streaming data applications. The object
accepts scalar or vector input of real or complex data, provides hardware-friendly control
signals, and has optional output frame control signals. You can achieve gigasamples-per-second
(GSPS) throughput by using vector input. The object implements a polyphase filter, with one
subfilter per input vector element. The hardware implementation interleaves the subfilters,
which results in sharing each filter multiplier (*FFT Length* /
*Input Size*) times. The object implements the same pipelined Radix 2^2 FFT
algorithm as the `dsphdl.FFT`

System object.

To channelize input data:

Create the

`dsphdl.Channelizer`

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
System object, `channelizer`

= dsphdl.Channelizer`channelizer`

, that implements a raised-cosine filter
and an 8-point FFT.

sets properties using one or more name-value arguments. `channelizer`

= dsphdl.Channelizer(`Name=Value`

)

## Properties

## Usage

### Syntax

### Description

`[`

filters and computes a fast Fourier transform, and returns the frequency channels,
`dataOut`

,`validOut`

]
= channelizer(`dataIn`

,`validIn`

)`dataOut`

, detected in the input signal, `dataIn`

,
when `validIn`

is `1`

(true). The
`validIn`

and `validOut`

arguments are logical
scalars that indicate the validity of the input and output signals, respectively.

`[`

returns the frequency channels, `dataOut`

,`validOut`

]
= channelizer(`dataIn`

,`validIn`

,`reset`

)`dataOut`

, detected in the input
signal, `dataIn`

, when `validIn`

is
`1`

(true) and `reset`

is `0`

(false). When `reset`

is `1`

(true), the object stops
the current calculation and clears all internal state.

To use this syntax, set the `ResetInputPort`

property to `true`

. For example:

channelizer = dsphdl.Channelizer(...,ResetInputPort=true); ... [dataOut,validOut] = channelizer(dataIn,validIn,reset)

`[`

returns the frequency channels, `dataOut`

,`startOut`

,`endOut`

,`validOut`

]
= channelizer(___)`dataOut`

, computed from the input
arguments of any of the previous syntaxes. `startOut`

is
`1`

(true) for the first sample of a frame of output data.
`endOut`

is `1`

(true) for the last sample of a
frame of output data.

To use this syntax, set the `StartOutputPort`

and `EndOutputPort`

properties to `true`

. For example:

channelizer = dsphdl.Channelizer(...,StartOutputPort=true,EndOutputPort=true); ... [dataOut,startOut,endOut,validOut] = channelizer(dataIn,validIn)

### 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

## Algorithms

## Extended Capabilities

## Version History

**Introduced in R2017a**