wlanNonHTConfig

Configure non-HT transmission

Description

The wlanNonHTConfig object is a configuration object for the WLAN non-high-throughput (non-HT) packet format.

Creation

Syntax

cfgNonHT = wlanNonHTConfig

cfgNonHT = wlanNonHTConfig(Name,Value)

Description

cfgNonHT = wlanNonHTConfig creates a configuration object that initializes parameters for an IEEE^® 802.11™ non-HT PPDU.

cfgNonHT = wlanNonHTConfig(Name,Value) sets properties using one or more name-value pairs. Enclose each property name in quotation marks. For example, wlanNonHTConfig('Modulation','DSSS') specifies the modulation type as direct-sequence spread spectrum (DSSS).

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

Properties

Modulation — Modulation type for non-HT transmission

'OFDM' (default) | 'DSSS'

Modulation type for the non-HT transmission, specified as 'OFDM' for orthogonal frequency division multiplexing (OFDM) or 'DSSS' for direct-sequence spread spectrum (DSSS).

Data Types: char | string

ChannelBandwidth — Channel bandwidth of PPDU transmission

'CBW20' (default) | 'CBW5' | 'CBW10' | 'CBW40' | 'CBW80' | 'CBW160'

Channel bandwidth of PPDU transmission, 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' — Channel bandwidth of 40 MHz for non-HT duplicate

• 'CBW80' — Channel bandwidth of 80 MHz for non-HT duplicate

• 'CBW160' — Channel bandwidth of 160 MHz for non-HT duplicate

Data Types: char | string

InactiveSubchannels — Indicate inactive 20 MHz subchannels in non-HT duplicate packet

false or 0 (default) | logical vector

Indicate inactive 20 MHz subchannels in a non-HT duplicate packet, specified as a numeric or logical 0 (false) or a logical vector with at least one element set to 0 (false). When you specify a vector, the elements correspond to subchannels in order of increasing absolute frequency. Each element indicates whether the corresponding 20 MHz subchannel is inactive. To indicate an inactive 20 MHz subchannel, set the corresponding element to 1 (true). If you set this property to 0 (false), the wlanNonHTConfig object applies that value to all 20 MHz subchannels, indicating that all subchannels are active.

Example: [0 0 0 1] indicates a non-HT duplicate packet such that the subchannel with the highest absolute frequency value is inactive.

Dependencies

To enable this property, set the ChannelBandwidth property to either 'CBW80' or 'CBW160'.

Data Types: logical

MCS — OFDM MCS used for transmission

0 (default) | integer in the interval [0, 7]

OFDM MCS used for transmission, specified as an integer in the interval [0, 7]. This table shows the modulation type and coding rate for each valid value of MCS.

Value of MCS	Modulation	Coding Rate	Coded Bits Per Subcarrier	Coded Bits Per OFDM Symbol	Data Bits Per OFDM Symbol	Data Rate in Mbps
						5-MHz Channel Bandwidth	10-MHz Channel Bandwidth	20-MHz Channel Bandwidth
0	Binary phase-shift keying (BPSK)	1/2	1	48	24	1.5	3	6
1	BPSK	3/4	1	48	36	2.25	4.5	9
2	quadrature phase-shift keying (QPSK)	1/2	2	96	48	3	6	12
3	QPSK	3/4	2	96	72	4.5	9	18
4	16-point quadrature amplitude modulation (16-QAM)	1/2	4	192	96	6	12	24
5	16-QAM	3/4	4	192	144	9	18	36
6	64-QAM	2/3	6	288	192	12	24	48
7	64-QAM	3/4	6	288	216	13.5	27	54

For more information, see Table 17-4 of [1].

Data Types: double

DataRate — Data rate for DSSS modulation

'1Mbps' (default) | '2Mbps' | '5.5Mbps' | '11Mbps'

Data rate for DSSS modulation, specified as a one of these values:

• '1Mbps' — Differential binary phase-shift keying (DBPSK) with a data rate of 1 Mbps

• '2Mbps' — Differential quadrature phase-shift keying (DQPSK) with a data rate of 2 Mbps

• '5.5Mbps' — Complementary code keying (CCK) with a data rate of 5.5 Mbps

• '11Mbps' — CCK with a data rate of 11 Mbps

Data Types: char | string

Preamble — DSSS modulation preamble type

'Long' (default) | 'Short'

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

Dependencies

The 'Short' value of this property does not apply when you set the DataRate property to '1Mbps'.

Data Types: char | string

LockedClocks — Clock locking indicator for DSSS modulation

true or 1 (default) | false or 0

Clock locking indicator for DSSS modulation, specified as a numeric or logical 1 (true) or 0 (false). This property corresponds to the locked clocks bit (bit b2) of the SERVICE field as specified in Section 16.2.3.5 of [1]. To indicate that the physical layer (PHY) implementation derives its transmit frequency clock and symbol clock from the same oscillator, set this property to 1 (true). For more information, see Sections 16.2.3.5 and 18.1.3 of [1].

Note

Section 18.3.2.2 of [1] specifies that the locked clocks bit must be 1 for all extended rate PHY (ERP) systems when transmitting at any of these rates:

• An optional ERP-packet binary convolutional coding (ERP-PBCC) rate

• A data rate described in Section 16 of [1]

Therefore, to model ERP systems, you must set this property to 1 (true).

Data Types: logical

PSDULength — PSDU length

1000 (default) | integer in the interval [1, 4095]

Physical layer convergence procedure (PLCP) service data unit (PSDU) length, in bytes, specified as an integer in the interval [1, 4095].

Data Types: double

NumTransmitAntennas — Number of transmit antennas

1 (default) | positive integer

Number of transmit antennas, specified as a positive integer.

Dependencies

To enable this property, set the ChannelBandwidth property to 'CBW20'.

CyclicShifts — Cyclic shift values of additional transmit antennas

-75 (default) | integer in the interval [–200, 0] | row vector

Cyclic shift values, in nanoseconds, of additional transmit antennas. The first eight antennas use the cyclic shift values specified in Table 21-10 of [1]. The remaining L antennas use the values you specify in this property, where L = NumTransmitAntennas – 8. Specify this property as one of these values:

• An integer in the interval [–200, 0] — the wlanNonHTConfig object uses this cyclic shift value for each of the L additional antennas.

• A row vector of length L of integers in the interval [–200, 0] — the wlanNonHTConfig object uses the kth element as the cyclic shift value for the (k + 8)th transmit antenna.

  Note

  If you specify this property as a row vector of length greater than L, the wlanNonHTConfig object uses only the first L elements. For example, if you set the NumTransmitAntennas property to 16, the wlanNonHTConfig object uses only the first L= 16 – 8 = 8 elements of this vector.

Dependencies

To enable this property, set the NumTransmitAntennas property to a value greater than 8.

Data Types: double

SignalChannelBandwidth — Signal channel bandwidth in scrambler sequence

false or 0 (default) | true or 1

Signal channel bandwidth in the scrambler sequence, specified as a numeric or logical 1 (true) or 0 (false). To signal the channel bandwidth, set this property to 1 (true). Otherwise, set this property to 0 (false). For more information, see Section 17.3.5.5 of [1].

Dependencies

To enable this property, set the Modulation property to 'OFDM'.

Data Types: logical

BandwidthOperation — Signal bandwidth operation in scrambler sequence

'Absent' (default) | 'Static' | 'Dynamic'

Signal bandwidth operation in the scrambler sequence, specified as one of these values.

• 'Absent' — Disable bandwidth operation signaling

• 'Static' — Signal static bandwidth operation

• 'Dynamic' — Signal dynamic bandwidth operation

For more information, see Section 17.3.5.5 of [1].

Data Types: char | string

Object Functions

scramblerRange	Get scrambler initialization range
transmitTime	Packet transmission time

Examples

Generate Data Field Signal of Non-HT Transmission

Configure transmission parameters by creating a wlanNonHTConfig object, specifying a channel bandwidth of 80 MHz and static bandwidth operation.

cfg = wlanNonHTConfig('ChannelBandwidth','CBW80','SignalChannelBandwidth',true, ... 
     'BandwidthOperation','Static');

Generate a random PSDU of the appropriate length.

psdu = randi([0 1],8*cfg.PSDULength,1,'int8');

Generate the initial pseudorandom scrambler sequence.

[range,numBits] = scramblerRange(cfg);
scramInit = randi(range);

Generate the non-HT Data field signal.

y = wlanNonHTData(psdu,cfg,scramInit);

Create Non-HT Format Configuration Object for DSSS Modulation

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

More About

OFDM PLCP Timing Parameters

Section 17 of [1] specifies OFDM PLCP 5 MHz, 10 MHz, and 20 MHz channel bandwidth operation.

This table lists timing parameters associated with the OFDM PLCP.¹ .

Parameter	Value	20 MHz Channel Bandwidth	10 MHz Channel Bandwidth	5 MHz Channel Bandwidth
NSD: Number of data subcarriers	48	48	48	48
NSP: Number of pilot subcarriers	4	4	4	4
NST: Total number of subcarriers	NSD + NSP	52	52	52
ΔF: Subcarrier frequency spacing, in MHz	(Channel bandwidth) / 64	0.3125	0.15625	0.078125
TFFT: Inverse Fast Fourier Transform (IFFT) / Fast Fourier Transform (FFT) period, in μs	1 / ΔF	3.2	6.4	12.8
TPREAMBLE: PLCP preamble duration, in μs	TSHORT + TLONG	16	32	64
TSIGNAL: Duration of the L-SIG symbol, in μs	TGI + TFFT	4	8	16
TGI: GI duration, in μs	TFFT/4	0.8	1.6	3.2
TGI2: Training symbol GI duration, in	TFFT/2	1.6	3.2	6.4
TSYM: Symbol interval, in μs	TGI + TFFT	4	8	16
TSHORT: L-STF duration, in μs	10 × TFFT /4	8	16	32
TLONG: L-LTF duration, in μs	TGI2 + 2 × TFFT	8	16	32
Note The standard refers to operation at 10 MHz as “half-clocked” and operation at 5 MHz as “quarter-clocked”.

PPDU

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

References

[1] IEEE Std 802.11-2020 (Revision of 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.

Extended Capabilities

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

Version History

Introduced in R2015b