主要内容

wlanNonHTOFDMDemodulate

Demodulate fields of non-HT OFDM waveform

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Syntax

sym = wlanNonHTOFDMDemodulate(rx,field,cfg)
sym = wlanNonHTOFDMDemodulate(rx,field,bandwidth)
sym = wlanNonHTOFDMDemodulate(___，“ ofdmsymboloffset”，symOffset)

描述

example

sym= wlanNonHTOFDMDemodulate(rx,field,cfg)recovers a frequency-domain signal by orthogonal frequency-division multiplexing (OFDM) demodulating non-high-throughput (non-HT) time-domain signalrx. The function demodulatesrxby using non-HT transmission parameterscfgand signal field valuefield.

sym= wlanNonHTOFDMDemodulate(rx,field,bandwidth)指定变速箱的通道带宽。

example

sym= wlanNonHTOFDMDemodulate(___，“ ofdmsymboloffset”，symOffset)specifies the OFDM symbol sampling offset as a fraction of the cyclic prefix length in addition to any combination of input arguments from the previous syntaxes..

例子

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打开实时脚本

Configure and generate a non-HT time-domain waveform.

cfg = wlannonhtconfig（'MCS'，4）;bit = randi（[0 1]，8*cfg.psdulength，1，'int8'）；waveform = wlanWaveformGenerator(bits,cfg);

Transmit the waveform through an additive white Gaussian noise (AWGN) channel with a signal-to-noise ratio (SNR) of 30.

snr = 30; rxWaveform = awgn(waveform,snr);

Extract the non-HT Data field from the received waveform.

field ='NonHT-Data';ind = wlanfieldindices（CFG，field）;rx = rxwaveform（ind（1）：ind（2），:);

Recover the frequency-domain signal by OFDM demodulating the time-domain data signal.

sym = wlanNonHTOFDMDemodulate(rx,field,cfg);

Extract the data subcarriers from the demodulated signal.

info = wlanNonHTOFDMInfo(field,cfg); sym = sym(info.DataIndices,:,:);

恢复PSDU并确认它与传输的PSDU匹配。

NoiseVarest = 10^（-snr/10）;psdu = wlanNonHTDataBitRecover(sym,noiseVarEst,cfg); isequal(bits,psdu)
ans =logical1
打开实时脚本

Configure and generate a non-HT Data signal with a channel bandwidth of 160 MHz and dynamic bandwidth operation.

bandwidth ='cbw160';cfg = wlannonhtconfig（'ChannelBandwidth'，带宽，“ psdulength”，1，...“ signalChannelBandWidth”,true,'BandwidthOperation','动态的'）；bit = randi（[0 1]，8*cfg.psdulength，1，'int8'）；[range，〜] = scramblerrange（cfg）;scraminit = randi（range）;y = wlannonhtdata（位，cfg，scraminit）;

Transmit the waveform through an AWGN channel with an SNR of 50.

SNR = 50;NoiseVarest = 10^（-snr/10）;rx = awgn（y，snr）;

Recover the frequency-domain signal by OFDM demodulating the non-HT Data signal, specifying an OFDM symbol sampling offset.

field ='NonHT-Data';Symoffset = 0.5;sym = wlannonhtofdmdemeDemeDemulate（rx，field，bandwidth，'OFDMSymbolOffset',symOffset);

提取数据子载波。

info = wlanNonHTOFDMInfo(field,bandwidth); sym = sym(info.DataIndices,:);

Recover the first 20 MHz subchannel of the PSDU, enhancing the demapping of the OFDM subcarriers by specifying channel state information. Confirm that the received and transmitted PSDUs match.

CSI =一个（48,1）;[psdu，scraminit] = wlannonhtdatabitrecover（sym（1:48，:)，noingsvarest，csi，cfg）;quequal（位，psdu）
ans =logical1

Recover and display bandwidth signaling by interpreting the scrambler state.

[带宽，dyn] = wlaninterpretscramblerstate（scraminit）
带宽='CBW160'
dyn =logical1

Input Arguments

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Received time-domain signal, specified as a complex-valued matrix of sizeNs-经过-Nr.

  • Nsis the number of time-domain samples. IfNsis not an integer multiple of the OFDM symbol length,Ls, for the specified field,then the function ignores the remainingmod（Ns,Ls)symbols.

  • Nris the number of receive antennas.

Data Types:double
Complex Number Support:Yes

要解调的字段，指定为这些值之一。

  • 'L-LTF'– Demodulate legacy long training field (L-LTF).

  • 'L-SIG'- 解码旧信号（L-SIG）字段。

  • 'NonHT-Data'– Demodulate the non-HT Data field.

Data Types:char|string

非HT传输参数，指定为wlanNonHTConfig目的。

Channel bandwidth, specified as one of these values.

  • 'CBW5'- - - - - - Channel bandwidth of 5 MHz

  • 'CBW10'- - - - - - Channel bandwidth of 10 MHz

  • 'CBW20'- - - - - - Channel bandwidth of 20 MHz

  • “CBW40”- 40 MHz的频道带宽

  • 'CBW80'- - - - - - Channel bandwidth of 80 MHz

  • 'cbw160'- 160 MHz的频道带宽

Data Types:char|string

OFDM symbol sampling offset, as a fraction of the cyclic prefix length, specified as a scalar in the interval [0, 1].

您指定的值指示了OFDM解调相对于循环前缀开头的起始位置。

例子：0.45

Data Types:double

Output Arguments

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解调的频域信号，作为一个大小的复杂值返回Nsc-经过-Nsym-经过-Nr.

  • Nscis the number of active occupied subcarriers in the demodulated field.

  • Nsym是OFDM符号的数量。

  • Nris the number of receive antennas.

Data Types:double
Complex Number Support:Yes

Extended Capabilities

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

Version History

Introduced in R2020b

See Also

Functions