主要内容

wlanS1GOFDMInfo

OFDM Information for S1G transmission

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Syntax

info = wlans1gofdminfo（field,cfg)
info = wlans1gofdminfo（field,cfg,OversamplingFactor=osf)

描述

example

info= wlans1gofdminfo（field,cfg)returnsinfo, a structure containing orthogonal frequency-division multiplexing (OFDM) information for the input field of a sub-1-Ghz (S1G) transmission parameterized by configuration objectcfg.

example

info= wlans1gofdminfo（field,cfg，过采样factor =osf)returns OFDM information for the specified oversampling factor. For more information about oversampling, seeFFT-Based Oversampling.

Examples

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打开实时脚本

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

生成用于S1G传输的WLAN波形。

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 =波形（ind.s1gsig（1）：ind.s1gsig（2），:);

执行OFDM解调S1G-SIG字段。

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，：，：:);飞行员= sym（info.pilotindices，：，：:);
打开实时脚本

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;

返回并显示S1G数据字段的OFDM信息。

info = wlans1gofdminfo（'S1G-Data',cfg,OversamplingFactor=osf); disp(info)
FFTLength: 48 CPLength: 12 NumSubchannels: 1 NumTones: 26 ActiveFrequencyIndices: [26x1 double] ActiveFFTIndices: [26x1 double] DataIndices: [24x1 double] PilotIndices: [2x1 double]

Input Arguments

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

  • 'S1G-LTF1'- 第一个S1G长训练领域（S1G-LTF1）的返回DM信息。

  • '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'- S1G信号B（S1G-SIG-B）字段的返回DM信息。

  • '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 awlanS1GConfig目的。

过采样因子，指定为标量大于或等于1的标量。过采样的循环前缀长度必须是整数样品数量。

Data Types:single|double|int8|INT16|INT32|int64|uint8|UINT16|uint32|uint64

Output Arguments

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OFDM信息，作为包含这些字段的结构返回。

Name Values 描述 Data Types
FFTLength Positive integer Length of the fast Fourier transform (FFT) double
CPLength Positive integer

Cyclic prefix length, in samples

 double
数字 非负整数

Number of active subcarriers

 double
numsubchannels Positive integer 20 MHz子通道的数量。这wlanS1GOFDMInfofunction always returns this field as1当数据包格式由cfg输入是'S1G-1M'，指示一个1-MHz的子通道。对于所有其他数据包格式，子通道带宽为2 MHz。 double
ActiveFrequencyIndi​​ces 整数的列矢量在间隔中[ -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,数字] 活动子载波中的数据索引 double
PilotIndices Column vector of integers in the interval [1,数字] 主动子载体中的飞行员指数 double

Data Types:struct

算法

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FFT-Based Oversampling

An超采样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 guardband width relative to the total signal bandwidth, thereby increasing 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 withNFFT子载体组成Ngguardband subcarriers on either side ofNstoccupied bandwidth subcarriers.

基于FFT的过采样。

Extended Capabilities

C/C++ Code Generation
使用MATLAB®CODER™生成C和C ++代码。

Version History

Introduced in R2019a

See Also

Functions

Objects