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wlanNonHTConfig

Create non-HT format configuration object

Syntax

cfgNonHT = wlanNonHTConfig
cfgNonHT = wlanNonHTConfig(Name,Value)

Description

example

cfgNonHT = wlanNonHTConfig creates a configuration object that initializes parameters for an IEEE® 802.11™ non-high throughput (non-HT) format PPDU.

For non-HT, subcarrier spacing and subcarrier allocation have channel bandwidth dependencies. For more information, see OFDM PLCP Timing Parameters.

example

cfgNonHT = wlanNonHTConfig(Name,Value) creates a non-HT format configuration object that overrides the default settings using one or more Name,Value pair arguments.

At runtime, the calling function validates object settings for properties relevant to the operation of the function.

Examples

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Create a non-HT configuration object with default settings. After creating the object update the number of transmit antennas.

cfgNHT = wlanNonHTConfig
cfgNHT = 

  wlanNonHTConfig with properties:

             Modulation: 'OFDM'
       ChannelBandwidth: 'CBW20'
                    MCS: 0
             PSDULength: 1000
    NumTransmitAntennas: 1

Update the number of transmit antennas to two.

cfgNHT.NumTransmitAntennas = 2
cfgNHT = 

  wlanNonHTConfig with properties:

             Modulation: 'OFDM'
       ChannelBandwidth: 'CBW20'
                    MCS: 0
             PSDULength: 1000
    NumTransmitAntennas: 2

Create a wlanNonHTConfig object for OFDM operation for a PSDU length of 2048 bytes.

cfgNHT = wlanNonHTConfig('Modulation','OFDM');
cfgNHT.PSDULength = 2048;
cfgNHT
cfgNHT = 

  wlanNonHTConfig with properties:

             Modulation: 'OFDM'
       ChannelBandwidth: 'CBW20'
                    MCS: 0
             PSDULength: 2048
    NumTransmitAntennas: 1

Create a wlanNonHTConfig object for DSSS operation for a PSDU length of 2048 bytes.

cfgNHT = wlanNonHTConfig('Modulation','DSSS','PSDULength',2048)
cfgNHT = 

  wlanNonHTConfig with properties:

      Modulation: 'DSSS'
        DataRate: '1Mbps'
    LockedClocks: 1
      PSDULength: 2048

Input Arguments

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Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside single quotes (' '). You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: 'Modulation','OFDM','MCS',7 specifies OFDM modulation with a modulation and coding scheme of 7, which assigns 64QAM and a 3/4 coding rate for the non-HT format packet.

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Modulation type for the non-HT transmission packet, specified as 'OFDM' or 'DSSS'.

Data Types: char | string

Channel bandwidth in MHz for OFDM, specified as 'CBW20', 'CBW10', or 'CBW5'. The default value of 'CBW20' sets the channel bandwidth to 20 MHz.

When channel bandwidth is 5 MHz or 10 MHz, only one transmit antenna is permitted and NumTransmitAntennas is not applicable.

Data Types: char | string

OFDM modulation and coding scheme to use for transmitting the current packet, specified as an integer from 0 to 7. The system configuration associated with an MCS setting maps to the specified data rate.

MCSModulationCoding RateCoded bits per subcarrier (NBPSC)Coded bits per OFDM symbol (NCBPS)Data bits per OFDM symbol (NDBPS)Data Rate (Mbps)
20 MHz channel bandwidth10 MHz channel bandwidth5 MHz channel bandwidth
0BPSK1/214824631.5
1BPSK3/41483694.52.25
2QPSK1/2296481263
3QPSK3/4296721894.5
416QAM1/241929624126
516QAM3/4419214436189
664QAM2/36288192482412
764QAM3/46288216542713.5

See IEEE Std 802.11-2012, Table 18-4.

Data Types: double

DSSS modulation data rate, specified as '1Mbps', '2Mbps', '5.5Mbps', or '11Mbps'.

  • '1Mbps' uses differential binary phase shift keying (DBPSK) modulation with a 1 Mbps data rate.

  • '2Mbps' uses differential quadrature phase shift keying (DQPSK) modulation with a 2 Mbps data rate.

  • '5.5Mbps' uses complementary code keying (CCK) modulation with a 5.5 Mbps data rate.

  • '11Mbps' uses complementary code keying (CCK) modulation with an 11 Mbps data rate.

For IEEE Std 802.11-2012, Section 16, only '1Mbps' and '2Mbps' apply

Data Types: char | string

DSSS modulation preamble type, specified as 'Long' or 'Short'.

  • When DataRate is '1Mbps', the Preamble setting is ignored and 'Long' is used.

  • When DataRate is greater than '1Mbps', the Preamble property is available and can be set to 'Long' or 'Short'.

For IEEE Std 802.11-2012, Section 16, 'Short' does not apply.

Data Types: char | string

Clock locking indication for DSSS modulation, specified as a logical. Bit 2 of the SERVICE field is the Locked Clock Bit. A true setting indicates that the PHY implementation derives its transmit frequency clock and symbol clock from the same oscillator. For more information, see IEEE Std 802.11-2012, Section 17.2.3.5 and Section 19.1.3.

Note

  • IEEE Std 802.11-2012, Section 19.3.2.2, specifies locked clocks is required for all ERP systems when transmitting at the ERP-PBCC rate or at a data rate described in Section 17. Therefore to model ERP systems, set LockedClocks to true.

Data Types: logical

Number of bytes carried in the user payload, specified as an integer from 1 to 4095.

Data Types: double

Number of transmit antennas for OFDM, specified as a scalar integer from 1 to 8.

When channel bandwidth is 5 MHz or 10 MHz, NumTransmitAntennas is not applicable because only one transmit antenna is permitted.

Data Types: double

Output Arguments

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Non-HT PPDU configuration, returned as a wlanNonHTConfig object. The properties of cfgNonHT are specified in wlanNonHTConfig Properties.

More About

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OFDM PLCP Timing Parameters

IEEE Std 802.11™-2012 [1], Section 18[1] specifies OFDM PLCP 20 MHz, 10 MHz, and 5 MHz channel bandwidth operation.

Timing parameters associated with the OFDM PLCP are listed in IEEE Std 802.11™-2012 [1], Table 18-5.

ParameterValue20 MHz channel bandwidth10 MHz channel bandwidth5 MHz channel bandwidth

NSD: Number of data subcarriers

48

48

48

48

NSP: Number of pilot subcarriers

4

4

4

4

NST: Number of subcarriers, total

NSD + NSP

52

52

52

ΔF: Subcarrier frequency spacing

(Channel BW in MHz) / 64

0.3125 MHz (= 20 / 64)

0.15625 MHz (= 10 / 64)

0.078125 MHz (= 5 / 64)

TFFT: Inverse Fast Fourier Transform (IFFT) / Fast Fourier Transform (FFT) period

1 / ΔF

3.2 μs

6.4 μs

12.8 μs

TPREAMBLE: PLCP preamble duration

TSHORT + TLONG16 μs32 μs64 μs

TSIGNAL: Duration of the L-SIG symbol

TGI + TFFT4.0 μs8.0 μs16.0 μs

TGI: GI duration

TFFT/40.8 μs1.6μs3.2 μs

TGI2: Training symbol GI duration

TFFT/21.6 μs3.2μs6.4 μs

TSYM: Symbol interval

TGI + TFFT4 μs8 μs16 μs

TSHORT: L-STF duration

10 × TFFT /48 μs16 μs32 μs

TLONG: L-LTF duration

TGI2 + 2 × TFFT8 μs16 μs32 μs

Note

The standard refers to operation at:

  • 10 MHz as “half-clocked”.

  • 5 MHz as “quarter-clocked”.

PPDU

The physical layer convergence procedure (PLCP) protocol data unit (PPDU) is the complete PLCP frame, including PLCP headers, MAC headers, the MAC data field, and the MAC and PLCP trailers.

References

[1] IEEE Std 802.11™-2012 IEEE Standard for Information technology — Telecommunications and information exchange between systems — Local and metropolitan area networks — Specific requirements — Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications.

Extended Capabilities

Introduced in R2015b


[1] IEEE Std 802.11-2012 Adapted and reprinted with permission from IEEE. Copyright IEEE 2012. All rights reserved.

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