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wlanLLTF

Generate L-LTF waveform

Description

y = wlanLLTF(cfg) generates an L-LTF1 time-domain waveform with transmission parameters cfg.

example

y = wlanLLTF(cfg,OversamplingFactor=osf) generates an oversampled L-LTF waveform with the specified oversampling factor. For more information about oversampling, see FFT-Based Oversampling.

Examples

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Generate the L-LTF for a 40 MHz single antenna VHT packet.

cfgVHT = wlanVHTConfig('ChannelBandwidth', 'CBW40');
y = wlanLLTF(cfgVHT);
size(y)
ans = 1×2

   320     1

plot(abs(y))
xlabel('Samples')
ylabel('Amplitude')

Figure contains an axes object. The axes object with xlabel Samples, ylabel Amplitude contains an object of type line.

The output L-LTF waveform contains 320 time-domain samples for a 40 MHz channel bandwidth.

Input Arguments

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Transmission parameters, specified as a wlanVHTConfig, wlanHTConfig, or wlanNonHTConfig object.

Oversampling factor, specified as a scalar greater than or equal to 1. The oversampled cyclic prefix length must be an integer number of samples.

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

Output Arguments

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L-LTF time-domain waveform, returned as an NS-by-NT matrix. NS is the number of time-domain samples, and NT is the number of transmit antennas.

NS is proportional to the channel bandwidth. The time-domain waveform consists of two symbols.

ChannelBandwidthNS
'CBW5', 'CBW10', 'CBW20'160
'CBW40'320
'CBW80'640
'CBW160'1280
'CBW320'2560

Data Types: double
Complex Number Support: Yes

More About

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Algorithms

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References

[1] IEEE Std 802.11ac™-2013 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 — Amendment 4: Enhancements for Very High Throughput for Operation in Bands below 6 GHz.

[2] 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

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

Version History

Introduced in R2015b


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