lteOFDMInfo

OFDM modulation related information

Syntax

``info = lteOFDMInfo(enb)``
``info = lteOFDMInfo(enb,Nfft)``

Description

example

````info = lteOFDMInfo(enb)` provides information related to the OFDM modulation performed by `lteOFDMModulate`, given the cell-wide settings structure, `enb`.```
````info = lteOFDMInfo(enb,Nfft)` specifies the number of IFFT points to use in the modulation.```

Examples

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Find the sampling rate of a 50 resource block configuration, corresponding to a 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
`NDLRB`Required

Scalar integer from 6 to 110

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

`CyclicPrefix`Optional

`'Normal'` (default), `'Extended'`

Cyclic prefix length

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

Data Types: `struct`

The number of IFFT points to use in the OFDM modulation, specified as a positive integer.

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.Nfft``CyclicPrefixLengths`
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

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