# ofdmdemod

Demodulate using OFDM method

## Syntax

## Description

demodulates the input time domain signal specified in `Y`

= ofdmdemod(`X`

,`nfft`

,`cplen`

)`X`

using
the orthogonal frequency division multiplexing (OFDM) method with an FFT size
specified by `nfft`

and cyclic prefix length specified by
`cplen`

. For information, see OFDM Demodulation.

removes null subcarriers from the locations specified in
`Y`

= ofdmdemod(`X`

,`nfft`

,`cplen`

,`symOffset`

,`nullidx`

)`nullidx`

. For this syntax, the symbol sampling offset is
applied to each OFDM symbol and the number of rows in the output is
`nfft`

–
`length(`

, which accounts for the
removal of null subcarriers. Use null subcarriers to account for guard bands and DC
subcarriers. For information, see Subcarrier Allocation and Guard Bands.`nullidx`

)

`[`

returns pilot subcarriers for the pilot indices specified in
`Y`

,`pilots`

] = ofdmdemod(`X`

,`nfft`

,`cplen`

,`symOffset`

,`nullidx`

,`pilotidx`

)`pilotidx`

. For this syntax, the symbol sampling offset is
applied to each OFDM symbol and number of rows in the output `Y`

is `nfft`

–
`length(`

–
`nullidx`

)`length(`

, which accounts for
the removal of null and pilot subcarriers. The function assumes that pilot
subcarrier locations are the same across each OFDM symbol and transmit
antenna.`pilotidx`

)

specifies the optional oversampling factor name-value argument in addition to input
arguments in previous syntaxes. The oversampling factor for an upsampled input
signal must be specified as a positive scalar, and the products
(`Y`

= ofdmdemod(`X`

,`nfft`

,`cplen`

,___,OversamplingFactor=Value)`OversamplingFactor`

×`nfft`

) and
(`OversamplingFactor`

×`cplen`

) must both
result in integers. The default value for `OversamplingFactor`

is
`1`

.

For example, `ofdmdemod(inSym,nfft,cplen,OversamplingFactor=2)`

demodulates assuming the input signal was upsampled by a factor of two.

**Tip**

If you set the oversampling factor to a noninteger rational number, specify a fractional value
rather than a decimal value. For example, with an FFT length of `12`

and an
oversampling factor of `4/3`

, their product is the integer
`16`

. However, rounding `4/3`

to
`1.333`

when setting the oversampling factor results in a noninteger
product of `15.9960`

, which results in a code error.

## Examples

## Input Arguments

## Output Arguments

## More About

## Algorithms

## Extended Capabilities

## Version History

**Introduced in R2018a**