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wlanS1GOFDMInfo

Get OFDM Information for S1G transmission

Description

example

info = wlanS1GOFDMInfo(field,cfg) returns info, a structure containing orthogonal frequency-division multiplexing (OFDM) information for the input field of a sub-1-Ghz (S1G) transmission parameterized by configuration object cfg.

Examples

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Get OFDM information for the S1G-Data field in a transmission with specified channel bandwidth.

Create a WLAN S1G format configuration object, specifying the channel bandwidth.

cfg = wlanS1GConfig('ChannelBandwidth','CBW1');

Return and display the OFDM information for the S1G-Data field.

info = wlanS1GOFDMInfo('S1G-Data',cfg);
disp(info)
                 FFTLength: 32
                  CPLength: 8
            NumSubchannels: 1
                  NumTones: 26
    ActiveFrequencyIndices: [26x1 double]
          ActiveFFTIndices: [26x1 double]
               DataIndices: [24x1 double]
              PilotIndices: [2x1 double]

Perform OFDM demodulation on the S1G-SIG field and extract the data and pilot subcarriers.

Generate a WLAN waveform for an S1G transmission.

cfg = wlanS1GConfig;
bits = [1; 0; 0; 1];
waveform = wlanWaveformGenerator(bits,cfg);

Obtain the field indices and extract the S1G-SIG field.

ind = wlanFieldIndices(cfg);
rx = waveform(ind.S1GSIG(1):ind.S1GSIG(2),:);

Perform OFDM demodulation on the S1G-SIG field.

sym = wlanS1GDemodulate(rx,'S1G-SIG',cfg);

Get the OFDM information, then extract the data and pilot subcarriers.

info = wlanS1GOFDMInfo('S1G-SIG',cfg);
data = sym(info.DataIndices,:,:);
pilots =  sym(info.PilotIndices,:,:);

Input Arguments

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

  • 'S1G-LTF1' – Return OFDM information for the first S1G long training field (S1G-LTF1).

  • 'S1G-SIG' – Return OFDM information for the S1G signaling (S1G-SIG) field.

  • 'S1G-LTF2N' – Return OFDM information for the subsequent S1G long training fields (S1G-LTF2N).

  • 'S1G-SIG-A' – Return OFDM information for the S1G signal A (S1G-SIG-A) field.

  • 'S1G-SIG-B' – Return OFDM information for the S1G signal B (S1G-SIG-B) field.

  • 'S1G-DLTF' – Return OFDM information for the S1G beamformed LTF (D-LTF).

  • 'S1G-Data' – Return OFDM information for the S1G-Data field.

Data Types: char | string

Physical layer (PHY) format configuration, specified as a wlanS1GConfig object.

Output Arguments

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OFDM information, returned as a structure containing these fields.

NameValuesDescriptionData Types
FFTLengthPositive integerLength of the fast Fourier transform (FFT)double
CPLengthPositive integer

Cyclic prefix length, in samples

double
NumTonesNonnegative integer

Number of active subcarriers

double
NumSubchannelsPositive integerNumber of 20-MHz subchannels. The wlanS1GOFDMInfo function always returns this field as 1 when the packet format defined by the cfg input is 'S1G-1M', indicating a single 1-MHz subchannel. For all other packet formats, the subchannel bandwidth is 2 MHz.double
ActiveFrequencyIndicesColumn vector of integers in the interval [-FFTLength/2, (FFTLength/2 – 1)]Indices of active subcarriers. Each element of this field is the index of an active subcarrier, such that the direct current (DC) or null subcarrier is at the center of the frequency band.double
ActiveFFTIndicesColumn vector of integers in the interval [1, FFTLength]Indices of active subcarriers within the FFTdouble
DataIndicesColumn vector of integers in the interval [1, NumTones]Indices of data within the active subcarriersdouble
PilotIndicesColumn vector of integers in the interval [1, NumTones]Indices of pilots within the active subcarriersdouble

Data Types: struct

Extended Capabilities

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

See Also

Functions

Objects

Introduced in R2019a