wlanVHTSTF

Generate VHT-STF waveform

Description

example

y = wlanVHTSTF(cfg) generates a VHT-STF[1] time-domain waveform for the specified configuration object. See VHT-STF Processing for waveform generation details.

Examples

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Create a VHT configuration object with an 80 MHz channel bandwidth. Generate and plot the VHT-STF waveform.

cfgVHT = wlanVHTConfig;
cfgVHT.ChannelBandwidth = 'CBW80';

vstfOut = wlanVHTSTF(cfgVHT);
size(vstfOut);
plot(abs(vstfOut))
xlabel('Samples')
ylabel('Amplitude')

The 80 MHz waveform is a single OFDM symbol with 320 complex time-domain output samples. The waveform contains the repeating short training field pattern.

Input Arguments

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Format configuration, specified as a wlanVHTConfig object.

Output Arguments

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VHT-STF 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.

ChannelBandwidthNS
'CBW20'80
'CBW40'160
'CBW80'320
'CBW160'640

See VHT-STF Processing for waveform generation details.

Data Types: double
Complex Number Support: Yes

More About

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VHT-STF

The very high throughput short training field (VHT-STF) is a single OFDM symbol (4 μs in length) that is used to improve automatic gain control estimation in a MIMO transmission. It is located between the VHT-SIG-A and VHT-LTF portions of the VHT packet.

The frequency domain sequence used to construct the VHT-STF for a 20 MHz transmission is identical to the L-STF sequence. Duplicate L-STF sequences are frequency shifted and phase rotated to support VHT transmissions for the 40 MHz, 80 MHz, and 160 MHz channel bandwidths. As such, the L-STF and HT-STF are subsets of the VHT-STF.

For a detailed description of the VHT-STF, see section 21.3.8.3.4 of IEEE® Std 802.11™-2016.

Algorithms

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VHT-STF Processing

The VHT-STF is one OFDM symbol long and is processed for improved gain control in MIMO configurations. For algorithm details, refer to IEEE Std 802.11ac™-2013 [1], Section 22.3.4.6.

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.

Extended Capabilities

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

Introduced in R2015b


[1] IEEE Std 802.11ac-2013 Adapted and reprinted with permission from IEEE. Copyright IEEE 2013. All rights reserved.