# lteOFDMInfo

OFDM modulation related information

## Description

example

info = lteOFDMInfo(enb) provides information related to the OFDM modulation performed by lteOFDMModulate, given the cell-wide settings structure, enb.

## Examples

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Find the sampling rate of a 50RB, corresponding to 10 MHz waveform after OFDM modulation.

enb = struct('NDLRB',50,'CyclicPrefix','Normal');
lteOFDMInfo(enb)
ans = struct with fields:
SamplingRate: 15360000
Nfft: 1024
Windowing: 6
CyclicPrefixLengths: [80 72 72 72 72 72 72 80 72 72 72 72 72 72]

## Input Arguments

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Cell-wide settings, specified as a structure. enb contains the following fields.

Parameter FieldRequired or OptionalValuesDescription
NDLRBRequired

Scalar integer from 6 to 110

Number of downlink resource blocks. (${N}_{\text{RB}}^{\text{DL}}$)

CyclicPrefixOptional

'Normal' (default), 'Extended'

Cyclic prefix length

WindowingOptionalNonnegative integerNumber of time-domain samples over which the function applies windowing and overlapping of OFDM symbols

Data Types: struct

## Output Arguments

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OFDM information, returned as a structure. info contains the following fields.

Sampling rate of the OFDM modulator, returned as an integer.

Data Types: double

Number of FFT points used in the OFDM modulator, returned as a scalar power of 2.

Data Types: uint32

Number of time-domain samples over which the function applies windowing and overlapping of OFDM symbols, returned as a nonnegative integer.

If enb.Windowing is absent, info.Windowing returns a default value chosen as a function of enb.NDLRB to compromise between the effective duration of cyclic prefix (and therefore the channel delay spread tolerance) and the spectral characteristics of the transmitted signal (not considering any additional FIR filtering). See lteOFDMModulate for details.

Data Types: int32

Cyclic prefix length (in samples) of each OFDM symbol in a subframe.

info.NfftCyclicPrefixLengths
for CyclicPrefix = 'Normal'for CyclicPrefix = 'Extended'
2048[160 144 144 144 144 144 144 160 144 144 144 144 144 144][512 512 512 512 512 512 512 512 512 512 512 512]
1024[80 72 72 72 72 72 72 80 72 72 72 72 72 72][256 256 256 256 256 256 256 256 256 256 256 256]
512[40 36 36 36 36 36 36 40 36 36 36 36 36 36][128 128 128 128 128 128 128 128 128 128 128 128]
256[20 18 18 18 18 18 18 20 18 18 18 18 18 18][64 64 64 64 64 64 64 64 64 64 64 64]
128[10 9 9 9 9 9 9 10 9 9 9 9 9 9][32 32 32 32 32 32 32 32 32 32 32 32]

Note

For info.Nfft < 2048, info.CyclicPrefixLengths are the CyclicPrefixLengths for info.Nfft = 2048 scaled by info.Nfft / 2048.

Data Types: uint32

Data Types: struct

## Version History

Introduced in R2014a