This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English version of the page.

Note: This page has been translated by MathWorks. Click here to see
To view all translated materials including this page, select Country from the country navigator on the bottom of this page.

wlanNonHTOFDMInfo

Return OFDM information for non-HT format

Syntax

info = wlanNonHTOFDMInfo(field)

Description

example

info = wlanNonHTOFDMInfo(field) returns a structure, info, containing orthogonal frequency-division multiplexing (OFDM) information for the input field, field, in a non-high-throughput (non-HT) format configuration.

Examples

collapse all

Obtain and display OFDM information for the non-HT-Data field.

info  =  wlanNonHTOFDMInfo('NonHT-Data');
disp(info);
                 FFTLength: 64
                  CPLength: 16
            NumSubchannels: 1
                  NumTones: 52
          ActiveFFTIndices: [52x1 double]
    ActiveFrequencyIndices: [52x1 double]
               DataIndices: [48x1 double]
              PilotIndices: [4x1 double]

Perform OFDM demodulation of the L-LTF for non-HT format configuration and extract the data and pilot subcarriers.

Generate a WLAN waveform for a non-HT format configuration.

cfg = wlanNonHTConfig;
bits = [1; 0; 0; 1];
waveform = wlanWaveformGenerator(bits,cfg);

Obtain the field indices and extract the L-LTF.

ind = wlanFieldIndices(cfg);
rx = waveform(ind.LLTF(1):ind.LLTF(2),:);

Perform OFDM demodulation on the L-LTF.

sym = wlanLLTFDemodulate(rx,cfg);

Return OFDM information, extracting the data and pilot subcarriers.

info = wlanNonHTOFDMInfo('L-LTF');
data = sym(info.DataIndices,:,:);
pilots = sym(info.PilotIndices,:,:);

Input Arguments

collapse all

Field for which to return OFDM information, specified as one of these values.

  • 'L-LTF': Return OFDM information for the legacy long training field (L-LTF).

  • 'L-SIG': Return OFDM information for the legacy signal (L-SIG) field.

  • 'NonHT-Data': Return OFDM information for the non-HT-Data field.

Data Types: char | string

Output Arguments

collapse all

OFDM information, returned as a structure containing the following fields.

Length of the fast Fourier transform (FFT), returned as a positive integer.

Data Types: double

Cyclic prefix length, in samples, returned as a positive integer.

Data Types: double

Number of active subcarriers, returned as a nonnegative integer.

Data Types: double

Number of 20-MHz subchannels, returned as a positive integer.

Data Types: double

Indices of active subcarriers, returned as a column vector of integers in the interval [-FFTLength/2, FFTLength/2 – 1]. Each entry of ActiveFrequencyIndices is the index of an active subcarrier such that the DC or null subcarrier is at the center of the frequency band.

Data Types: double

Indices of active subcarriers within the FFT, returned as a column vector of positive integers in the interval [1, FFTLength].

Data Types: double

Indices of data within the active subcarriers, returned as a column vector of positive integers in the interval [1, NumTones].

Data Types: double

Indices of pilots within the active subcarriers, returned as a column vector of integers in the interval [1, NumTones].

Data Types: double

Data Types: struct

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

See Also

Functions

Objects

Introduced in R2019a