ofdmmod
Modulate frequency-domain signal using orthogonal frequency division multiplexing (OFDM)
Syntax
Description
performs OFDM modulation on the frequency-domain input data subcarriers,
ofdmSig
= ofdmmod(inSym
,nfft
,cplen
)inSym
, using an FFT size specified by
nfft
and cyclic prefix length specified by
cplen
. For information, see OFDM Modulation.
inserts null subcarriers into the frequency domain input data signal prior to
performing OFDM modulation. The null subcarriers are inserted at index locations
from 1 to ofdmSig
= ofdmmod(inSym
,nfft
,cplen
,nullidx
)nfft
, as specified by nullidx
.
For this syntax, the number of rows in the input inSym
must be
nfft
–
length(
. Use null carriers to
account for guard bands and DC subcarriers. For information, see Subcarrier Allocation, Guard Bands and Guard Intervals.nullidx
)
inserts null and pilot subcarriers into the frequency domain input data symbols
prior to performing OFDM modulation. The null subcarriers are inserted at the index
locations specified by ofdmSig
= ofdmmod(inSym
,nfft
,cplen
,nullidx
,pilotidx
,pilots
)nullidx
. The pilot subcarriers,
pilots
, are inserted at the index locations specified by
pilotidx
. For this syntax, the number of rows in the input
inSym
must be nfft
–
length(
–
nullidx
)length(
. The function
assumes 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 output
signal must be specified as a positive scalar. Additionally, the products
(ofdmSig
= ofdmmod(inSym
,nfft
,cplen
,___,OvesamplingFactor=Value)OversamplingFactor
×nfft
) and
(OversamplingFactor
×cplen
) must both
result in integers. The default value for OversamplingFactor
is
1
.
For example, ofdmmod(inSym,nfft,cplen,OversamplingFactor=2)
upsamples the output signal by a factor of two.
Examples
Input Arguments
Output Arguments
More About
Extended Capabilities
Version History
Introduced in R2018a