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wlanMPDUDecode

Decode MPDU

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Syntax

[cfgMAC,payload,status] = wlanMPDUDecode(mpdu)
[cfgMAC,payload,status] = wlanMPDUDecode(mpdu,phyFormat)
[cfgMAC,payload,status] = wlanMPDUDecode(mpdu,cfgPHY)
[cfgMAC,payload,status] = wlanMPDUDecode(___,Name=Value)

Description

[cfgMAC,payload,status] = wlanMPDUDecode(mpdu) validates the frame check sequence (FCS) and decodes the specified MAC protocol data unit (MPDU), mpdu. The function returns cfgMAC, a wlanMACFrameConfig configuration object, payload, one or more MAC service data units (MSDUs), and status, the result of the MPDU decoding.

[cfgMAC,payload,status] = wlanMPDUDecode(mpdu,phyFormat) validates the FCS and decodes the specified MPDU by using the parameters appropriate for the specified PHY format, phyFormat.

example

[cfgMAC,payload,status] = wlanMPDUDecode(mpdu,cfgPHY) validates the FCS and decodes the specified MPDU by using PHY transmission parameters, cfgPHY.

example

[cfgMAC,payload,status] = wlanMPDUDecode(___,Name=Value) specifies options using one or more name-value arguments in addition any input argument combination from previous syntaxes.

example

Examples

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Open Live Script

Create a WLAN MAC frame configuration object for an MPDU in high-efficiency single-user (HE SU) format, and then generate the MPDU.

phyFormat = 'HE-SU';
cfgMAC =  wlanMACFrameConfig('FrameFormat',phyFormat);
payload = randi([0 255],1,40);
mpdu = wlanMACFrame(payload,cfgMAC,'OutputFormat','bits');

Return the MSDUs by decoding the MPDU for the specified PHY format configuration.

[rxCfgMAC,payload,status] = wlanMPDUDecode(mpdu,phyFormat);

Confirm successful decoding by displaying the status.

disp(status)
    Success
Open Live Script

Create a WLAN MAC frame configuration object for a QoS Data frame, and then generate the MPDU.

cfgMAC = wlanMACFrameConfig('FrameType','QoS Data');
payload = randi([0 255],1,40);
mpdu = wlanMACFrame(payload,cfgMAC,'OutputFormat','bits');

Create a non-high-throughput-format (non-HT-format) configuration object with default settings.

cfgPHY = wlanNonHTConfig;

Return the MSDUs by decoding the MPDU for the specified PHY format configuration.

[cfgMAC,payload,status] = wlanMPDUDecode(mpdu,cfgPHY);

Confirm successful decoding by displaying the status.

disp(status)
    Success
Open Live Script

Deaggregate a VHT A-MPDU and decode the extracted MPDUs.

Create a WLAN MAC frame configuration object for a VHT A-MPDU.

txCfgMAC = wlanMACFrameConfig('FrameType','QoS Data', ...
    'FrameFormat','VHT');

Create a VHT-format configuration object with default settings.

cfgPHY = wlanVHTConfig;

Generate a random payload of eight MSDUs.

txPayload =  repmat({randi([0 255],1,40)},1,8);

Generate the A-MPDU containing eight MPDUs for the specified MAC and PHY configurations.

ampdu = wlanMACFrame(txPayload,txCfgMAC,cfgPHY);

Extract the list of MPDUs by deaggregating the A-MPDU. Display the status of the deaggregation and the delimiter CRC.

[mpduList,failCRC,status] = wlanAMPDUDeaggregate(ampdu,cfgPHY, ...
    'DataFormat','octets');
disp(status)
    Success

disp(failCRC)
   0   0   0   0   0   0   0   0

Decode all of the MPDUs in the extracted. Confirm successful decoding by displaying the status.

if strcmp(status,'Success')
    for i = 1:numel(mpduList)
        if ~failCRC(i)
            [cfgMAC,payload,status(i)] = ...
                wlanMPDUDecode(mpduList{i},cfgPHY, ...
                'DataFormat','octets');
        end
    end
end
disp(status)
    Success    Success    Success    Success    Success    Success    Success    Success

Input Arguments

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MPDU to be decoded, specified as one of these values.

  • A binary-valued vector representing the MPDU in bit form

  • A vector of integers in the interval [0, 255] representing octets in decimal format

  • A string scalar representing the MPDU as octets in hexadecimal format

  • A character vector representing the MPDU as octets in hexadecimal format

  • A character array, where each row represents an octet in hexadecimal format

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | char | string

PHY format, specified as one of these values.

  • 'HE-SU' — High-efficiency single-user (HE SU) format

  • 'HE-EXT-SU' — HE extended-range SU (HE ER SU) format

  • 'HE-MU' — HE multi-user (HE MU) format

  • 'HE-TB' — HE trigger-based (HE TB) format

  • 'VHT' — Very-high-throughput (VHT) format

  • 'HT' — High-throughput (HT) format

  • 'Non-HT' — Non-HT format

  • 'EHT-SU' — Extremely high-throughput SU (EHT SU) format

Data Types: char | string

PHY format and transmission parameters, specified as one of these objects.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: DataFormat='octets'

Format of input MPDU, specified as one of these values.

  • 'bits' — Specify the mpdu input in bit format

  • 'octets' — Specify the mpdu input in octet format

Data Types: char | string

Suppress warning messages, specified as one of these values.

  • false or 0 — Allow warning messages.

  • true or 1 — Suppress warning messages.

Data Types: logical

Mesh frame indication, specified as a numeric or logical 1 (true) or 0 ( false). To indicate that the frame originates from a mesh station in a mesh BSS, set this property to 1 (true). The function uses this argument only when decoding a frame of type QoS Data or QoS Null.

Data Types: logical

Output Arguments

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MAC frame configuration, returned as a wlanMACFrameConfig object.

One or more MSDUs, returned as a cell array of character arrays. The function returns a character array for each MSDU. In these character arrays, each row is the hexadecimal representation of an octet. For each MAC frame that contains no data, the function returns payload as an empty cell array.

Data Types: cell

Status of MPDU decoding, returned as an integer in the interval [–31, 0]. Each value of status corresponds to a member of the wlanMACDecodeStatus enumeration class, which indicates the status of MAC frame decoding according to this table.

Enumeration ValueMember of Enumeration ClassDecoding Status
0SuccessMAC frame successfully decoded
-1FCSFailedFrame check sequence (FCS) failed
-2InvalidProtocolVersionInvalid protocol version
-3UnsupportedFrameTypeUnsupported frame type
-4UnsupportedFrameSubtypeUnsupported frame subtype
-5NotEnoughDataInsufficient data to decode frame
-6UnsupportedBAVariantUnsupported variant of Block Ack frame
-7UnknownBitmapSizeUnknown bitmap size
-8UnknownAddressExtModeUnknown address extension mode
-9MalformedAMSDULengthMalformed aggregate MAC service data unit (A-MSDU) with invalid length
-10MalformedSSIDMalformed service set identifier (SSID) information element (IE)
-11MalformedSupportedRatesIEMalformed supported rates IE
-12MalformedIELengthMalformed IE length field
-13MissingMandatoryIEsMandatory IEs missing
-14NoMPDUFoundNo MPDU found in A-MPDU
-15CorruptedAMPDUAll the delimiters in received A-MPDU failed cyclic redundancy check (CRC)
-16InvalidDelimiterLengthInvalid length field in MPDU delimiter
-17MaxAMSDULenthExceededA-MSDU exceeds maximum length limit
-18MaxMPDULengthExceededMPDU exceeds maximum length limit
-19MaxMMPDULengthExceededMAC management frame exceeds maximum length limit
-20MaxMSDULengthExceededMSDU exceeds maximum length limit
-21UnexpectedProtectedFrameInvalid value of protected bit for this frame type
-22UnsupportedTriggerTypeUnsupported trigger frame type
-23UnknownHELTFTypeAndGIUnknown guard interval (GI) and high-efficiency long training field (HE-LTF) type
-24UnknownAPTxPowerUnknown value for AP Tx Power subfield of Common Info field
-25UnknownAID12ValueUnknown value for AID12 subfield of User Info field
-26UnknownRUAllocationUnknown value for B7-B1 in RU Allocation subfield of User Info field
-27UnknownULMCSUnknown value for UL MCS subfield of User Info field
-28UnknownTargetRSSIUnknown value for UL Target RSSI subfield of User Info field
-29UnsupportedBARTypeUnsupported value for BAR Type subfield of BAR Control field
-30MissingUserInfoReceived trigger frame contains invalid User Info field
-31InvalidLSIGLengthInvalid value for UL Length subfield of Common Info field, corresponding to length of legacy signal (L-SIG) field.

An enumeration value other than 0 means that MPDU decoding failed. If the decoding fails, the cfgMAC output displays no properties, and the function returns the payload output as an empty cell array.

Data Types: int16

Extended Capabilities

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

Version History

Introduced in R2019a

See Also

Functions

Objects

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