wlanHESIGABitRecover

Recover information bits in HE-SIG-A field

Description

example

[bits,failCRC] = wlanHESIGABitRecover(siga,noiseVarEst) recovers bits, the information bits contained in siga, the HE-SIG-A field of an IEEE® 802.11™ high-efficiency transmission subject to channel noise with estimated variance noiseVarEst. The function also returns failCRC, the result of the cyclic redundancy check (CRC) on bits.

For more information on 802.11ax™ signal recovery, see 802.11ax Signal Recovery with Preamble Decoding.

example

[bits,failCRC] = wlanHESIGABitRecover(siga,noiseVarEst,csi) also enhances the demapping of orthogonal frequency-division multiplexing (OFDM) subcarriers by using channel state information csi.

Examples

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Recover the information bits in the HE-SIG-A field of a WLAN HE single-user (HE-SU) waveform.

Create a WLAN HE-SU-format configuration object with default settings and use it to generate an HE-SU waveform.

cfgHE = wlanHESUConfig;
cbw = cfgHE.ChannelBandwidth;
waveform = wlanWaveformGenerator(1,cfgHE);

Obtain the WLAN field indices, which contain the HE-SIG-A field.

ind = wlanFieldIndices(cfgHE);
rxSIGA = waveform(ind.HESIGA(1):ind.HESIGA(2),:);

Perform orthogonal frequency-division multiplexing (OFDM) demodulation to extract the HE-SIG-A field.

sigaDemod = wlanHEDemodulate(rxSIGA,'HE-SIG-A',cbw);

Return the pre-HE OFDM information and extract the demodulated HE-SIG-A symbols.

preHEInfo = wlanHEOFDMInfo('HE-SIG-A',cbw);
siga = sigaDemod(preHEInfo.DataIndices,:);

Recover the HE-SIG-A information bits and other information, assuming no channel noise. Display the parity check result.

noiseVarEst = 0;
[bits,failCRC] = wlanHESIGABitRecover(siga,noiseVarEst);
disp(failCRC);
   0

Recover the information bits in the HE-SIG-A field of a WLAN HE multiuser (HE-MU) waveform with specified channel state information.

Create a WLAN HE-MU-format configuration object with default settings and use it to generate an HE-MU waveform.

cfgHE = wlanHEMUConfig(0);
cbw = cfgHE.ChannelBandwidth;
waveform = wlanWaveformGenerator(1,cfgHE);

Obtain the WLAN field indices, which contain the modulated HE-SIG-A symbols.

ind = wlanFieldIndices(cfgHE);
rxSIGA = waveform(ind.HESIGA(1):ind.HESIGA(2),:);

Perform OFDM demodulation to extract the HE-SIG-A field.

sigaDemod = wlanHEDemodulate(rxSIGA,'HE-SIG-A',cbw);

Return the pre-HE OFDM information and extract the demodulated HE-SIG-A symbols.

preHEInfo = wlanHEOFDMInfo('HE-SIG-A',cbw);
siga = sigaDemod(preHEInfo.DataIndices,:);

Specify the channel state information and assume no channel noise.

csi = ones(52,1);
noiseVarEst = 0;

Recover the HE-SIG-A information bits and other information. Display the CRC result.

[bits,failCRC] = wlanHESIGABitRecover(siga,noiseVarEst,csi);
disp(failCRC);
   0

Input Arguments

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Demodulated HE-SIG-A symbols, specified as a complex-valued matrix. The size of siga depends on the packet format.

  • For high-efficiency single-user (HE SU) or high-efficiency multiuser (HE MU) packets, specify a 52-by-2 matrix.

  • For high-efficiency extended-range single-user (HE ER SU) packets, specify a 52-by-4 matrix.

Data Types: double
Complex Number Support: Yes

Channel noise variance estimate, specified as a nonnegative scalar.

Data Types: double

Channel state information, specified as a 52-by-1 real-valued vector. To use the channel state information for enhanced demapping of the orthogonal frequency-division multiplexing (OFDM) symbols, specify this argument.

Data Types: double

Output Arguments

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Information bits recovered from HE-SIG-A field, returned as a 52-by-1 binary column vector.

Data Types: int8

CRC result, returned as a logical value of 1 (true) or 0 (false). The function returns this argument as 1 (true) if the recovered bits fail the CRC. The function returns this argument as 0 (false) if the recovered bits pass the CRC.

Data Types: logical

References

[1] IEEE Std 802.11– 2016. “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications." IEEE Standard for Information Technology – Telecommunications and information exchange between systems – Local and metropolitan area networks – Specific requirements.

[2] IEEE P802.11ax/D3.1 “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications. Amendment 6: Enhancements for High Efficiency WLAN." Draft Standard for Information Technology – Telecommunications and information exchange between systems – Local and metropolitan area networks – Specific requirements.

Extended Capabilities

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

Introduced in R2019a