WLAN 802.11ax transmitter tests, receiver tests, conformance testing
This page describes WLAN 802.11ax transmitter and receiver specifications as defined in IEEE 802.11ax standard. The 802.11ax radio conformance test equipments or solutions are used to conduct 11ax transmitter tests and 11ax receiver tests.
What is WLAN 802.11ax ?
IEEE has recently published draft version of 802.11ax standard known as wifi-6. The standard is going to be ratified in 2019. It is successor to 802.11ac but operates in both 2.4 GHz and 5 GHz bands. There are many new features added in newly released standard such as OFDMA in both downlink and uplink, MU-MIMO with beamforming in the downlink, MU-MIMO in the uplink, 1024-QAM, increased guard and symbol duration, larger bandwith (upto 160 MHz), BSS color, special packet format for outdoor applications and so on.
Refer WLAN 802.11ax tutorial >>.
WLAN 802.11ax Transmitter Tests
The figure-1 depicts test setup used for testing transmitter part of 802.11ax device (i.e. 11ax station).
Following table mentions 802.11ax transmitter tests.
|Transmitter Specifications||Descriptions with limits|
|EVM (Error Vector Magnitude)||-35 dB (For 1024QAM)|
|Unused tone error (for 11ax Stations)||
Subcarriers in close proximity to active RU26 subcarriers must lie 2 dB under EVM limit. For distant subcarriers, EVM requirement is reduced in 10dB steps down to -35 dB. THe figure depicts limit value for RU26. For other RU sizes, there is different limits and step widths defined in the 802.11ax standard.
|Frequency offset & timing offset||In this test, Initially trigger frame is sent to DUT using R&S SGT 100A or any compliant generator equipment and DUT responds with HE_TRIG frame towards R&S FSW analyzer. Relative frequency error (Center frequency offset, tolerance +/- 350 Hz) of response signal in the uplink as well as delay between end of trigger frame and start of response frame (timing accuracy, tolerance +/- 0.4 µs) are measured.|
WLAN 802.11ax Receiver Tests
Following table mentions 802.11ax receiver tests.
|Receiver Specifications||Descriptions with limits|
|Sensitivity test||At low power (about -43dBm) at the receiver for 1024QAM modulation test, only 10% of received packets should contain faulty bits.|
802.11ax radio conformance test equipments or solutions
Following is the list of 802.11ax radio conformance and other test solutions.
➤802.11ax test equipments should have EVM better than -35 dB with margin of atleast 10 dB. R&S spectrum and signal analyzer support EVM less than -53 dB. Hence measurement error of only 0.07 can be achieved with this 11ax equipments. R&S VSG (Vector Signal Generator) also offers EVM as required by 11ax specifications.
➤Keysight technologies offers 802.11ax test solutions validating various 11ax features which include OFDMA, MU-MIMO, 1024QAM constellation diagram with EVM, baseband IQ and so on.
➤Anritsu Corporation has launched Universal Wireless Test Set (MT8870A) which offers 802.11ax transmitter and receiver testing.
➤zSignal™ 802.11ax Software from LitePoint Corporation.
➤NI (National Instruments) has introduced test solution for 802.11ax High-Efficiency (HE) devices.
WLAN 802.11ac RF PHY conformance tests
Refer Article on 802.11ac RF/PHY conformance testing >> for more information. The figure shows one such 802.11ac transmitter test for power spectrum mask validation.
• IEEE 802.11ax draft standard
RF and Baseband Measurement Links
IEEE 802.11ax Related Links
IoT Wireless Technologies
RF Wireless Test and Measurement Solutions
Test and Measurement Equipments
BER Testing equipments
Agilent T & M Solutions
Anritsu T & M Solutions
Rohde & Schwarz T & M solutions
wireless channel emulator
Vector signal generator
Vector signal analyzer
Power Analyzer Equipments