wlanS1GOFDMInfo
OFDM Information for S1G transmission
Description
Examples
Demodulate S1G-SIG Field and Get OFDM Information
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,:,:);
Get OFDM Information for S1G-Data Field
Get OFDM information for the S1G-Data field in a transmission with specified channel bandwidth and oversampling factor.
Create a WLAN S1G format configuration object, specifying the channel bandwidth.
cfg = wlanS1GConfig('ChannelBandwidth','CBW1');
Specify an oversampling factor.
osf = 1.5;
Return and display the OFDM information for the S1G-Data field.
info = wlanS1GOFDMInfo('S1G-Data',cfg,OversamplingFactor=osf);
disp(info)
FFTLength: 48 SampleRate: 1500000 CPLength: 12 NumSubchannels: 1 NumTones: 26 ActiveFrequencyIndices: [26x1 double] ActiveFFTIndices: [26x1 double] DataIndices: [24x1 double] PilotIndices: [2x1 double]
Input Arguments
field
— Field for which to return OFDM information
'S1G-LTF1'
| 'S1G-SIG'
| 'S1G-LTF2N'
| 'S1G-SIG-A'
| 'S1G-SIG-B'
| 'S1G-DLTF'
| 'S1G-Data'
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
cfg
— PHY format configuration
wlanS1GConfig
object
Physical layer (PHY) format configuration, specified as a wlanS1GConfig
object.
osf
— Oversampling factor
1
(default) | scalar greater than or equal to 1
Oversampling factor, specified as a scalar greater than or equal to 1. The oversampled cyclic prefix length must be an integer number of samples.
Data Types: single
| double
| int8
| int16
| int32
| int64
| uint8
| uint16
| uint32
| uint64
Output Arguments
info
— OFDM information
structure
OFDM information, returned as a structure containing these fields.
Name | Values | Description | Data Types |
---|---|---|---|
FFTLength | Positive integer | Length of the fast Fourier transform (FFT) | double |
SampleRate | Positive scalar | Sample rate of the waveform | double |
CPLength | Positive integer | Cyclic prefix length, in samples | double |
NumTones | Nonnegative integer | Number of active subcarriers | double |
NumSubchannels | Positive integer | Number of 20 MHz subchannels | double |
ActiveFrequencyIndices | Column 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 |
ActiveFFTIndices | Column vector of integers in the interval [1,
FFTLength ] | Indices of active subcarriers within the FFT | double |
DataIndices | Column vector of integers in the interval [1,
NumTones ] | Indices of data within the active subcarriers | double |
PilotIndices | Column vector of integers in the interval [1,
NumTones ] | Indices of pilots within the active subcarriers | double |
Data Types: struct
Algorithms
FFT-Based Oversampling
An oversampled signal is a signal sampled at a frequency that is higher than the Nyquist rate. WLAN signals maximize occupied bandwidth by using small guardbands, which can pose problems for anti-imaging and anti-aliasing filters. Oversampling increases the guardband width relative to the total signal bandwidth, which increases the number of samples in the signal.
This function performs oversampling by using a larger IFFT and zero pad when generating an OFDM waveform. This diagram shows the oversampling process for an OFDM waveform with NFFT subcarriers made up of Ng guardband subcarriers on either side of Nst occupied bandwidth subcarriers.
Extended Capabilities
C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.
Version History
Introduced in R2019a
MATLAB 명령
다음 MATLAB 명령에 해당하는 링크를 클릭했습니다.
명령을 실행하려면 MATLAB 명령 창에 입력하십시오. 웹 브라우저는 MATLAB 명령을 지원하지 않습니다.
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
You can also select a web site from the following list:
How to Get Best Site Performance
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)