WiFi 6 802.11ax Receiver input sensitivity testing
This page describes Receiver input sensitivity test and measurement as per IEEE 802.11ax (WiFi 6). The receiver sensitivity testing setup for wifi 6 device is described along with 11ax conformance specifications.
What is receiver sensitivity ?
The receiver sensitivity test checks whether the receiver decodes the data as desired with specified PER (Packet Error Rate) or FER (Frame Error Rate) at minimum input power level possible.
Successful demodulation is estimated by PER of less than 10% or as specified in the conformance requirement. Different wireless technologies specify different limits as per channel conditions.
Minimum input sensitivity level depends on following three parameters of the physical layer of IEEE 802.11ax or
any other standard.
• Modulation scheme
• FEC coding rate
• Bandwidth
WiFi 6 802.11ax Receiver input sensitivity test and measurement
The figure depicts test setup for receiver input sensitivity tests as defined in wifi-6 standard IEEE 802.11ax. As shown VSG (Vector Signal Generator) or Wireless test set is used to feed the 11ax compliant WLAN signal to the DUT (Device Under Test). The power level of the test signal is slowly changed to check the demodulated output of the DUT. For 11ax i.e. wifi-6 the receiver input sensitivity measurement is done at PER of 10%. The test requires HE SU PPDUs with 4096 bytes in size and 800 ns guard interval. For PPDU with 20 MHz bandwidth, BCC type is used as FEC scheme. For PPDU with bandwidth greater than 20 MHz, LDPC is used as FEC scheme. The table mentions minimum sensitivity requirements with various modulation, coding rate and bandwidths.
| Modulation | Coding Rate | Min.sensitivity (20 MHz) | Min.sensitivity (40 MHz) | Min.sensitivity (80 MHz) | Min.sensitivity (160 or 80+80 MHz) |
|---|---|---|---|---|---|
| BPSK | 1/2 | -82 dBm | -79 dBm | -76 dBm | -73 dBm |
| QPSK | 1/2 | -79 | -76 | -73 | -70 |
| QPSK | 3/4 | -77 | -74 | -71 | -68 |
| 16QAM | 1/2 | -74 | -71 | -68 | -65 |
| 16QAM | 3/4 | -70 | -67 | -64 | -61 |
| 64QAM | 2/3 | -66 | -63 | -60 | -57 |
| 64QAM | 3/4 | -65 | -62 | -59 | -56 |
| 64QAM | 5/6 | -64 | -61 | -58 | -55 |
| 256QAM | 3/4 | -59 | -56 | -53 | -50 |
| 256QAM | 5/6 | -57 | -54 | -51 | -48 |
| 1024QAM | 3/4 | -54 | -51 | -48 | -45 |
| 1024QAM | 5/6 | -52 | -49 | -46 | -43 |
The other 11ax receiver tests include adjacent and non-adjacent channel rejection, receiver maximum input level etc.
References:
• IEEE 802.11ax standard and WLAN 11ax conformance specifications
RF and Baseband Measurement Links
WiFi 6 Resources as per IEEE 802.11ax
Useful Links to Legacy WLAN Standards
IoT Wireless Technologies
RF Wireless Test and Measurement Solutions
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
Protocol Analyzer