RFWiFi 6 (802.11ax) Receiver Input Sensitivity Testing
This page describes the receiver input sensitivity test and measurement as per IEEE 802.11ax (WiFi 6). We’ll cover the receiver sensitivity testing setup for a WiFi 6 device, along with relevant 11ax conformance specifications.
What is Receiver Sensitivity?
The receiver sensitivity test verifies whether the receiver can accurately decode data, achieving the specified PER (Packet Error Rate) or FER (Frame Error Rate) at the lowest possible input power level. Successful demodulation is typically determined by a PER of less than 10%, or as otherwise specified in the conformance requirements.
Different wireless technologies define varying limits depending on channel conditions. The minimum input sensitivity level hinges on these three parameters of the IEEE 802.11ax physical layer (or any other standard):
- Modulation scheme
- FEC coding rate
- Bandwidth
WiFi 6 802.11ax Receiver Input Sensitivity Test Setup
Here’s a visual representation of the receiver input sensitivity test and measurement setup for an 802.11ax WiFi 6 device:
As the figure illustrates, a 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 gradually adjusted to observe the demodulated output of the DUT. For 11ax (WiFi 6), the receiver input sensitivity measurement is taken at a PER of 10%.
The test utilizes HE SU PPDUs (High Efficiency Single User Physical Protocol Data Units) with a size of 4096 bytes and a guard interval of 800 ns.
- For PPDUs with a 20 MHz bandwidth, BCC (Binary Convolutional Coding) is employed as the FEC (Forward Error Correction) scheme.
- For PPDUs with bandwidths greater than 20 MHz, LDPC (Low-Density Parity-Check) is used as the FEC scheme.
Minimum Sensitivity Requirements
The following table outlines the minimum sensitivity requirements for various modulation, coding rates, 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 dBm | -76 dBm | -73 dBm | -70 dBm |
| QPSK | 3/4 | -77 dBm | -74 dBm | -71 dBm | -68 dBm |
| 16QAM | 1/2 | -74 dBm | -71 dBm | -68 dBm | -65 dBm |
| 16QAM | 3/4 | -70 dBm | -67 dBm | -64 dBm | -61 dBm |
| 64QAM | 2/3 | -66 dBm | -63 dBm | -60 dBm | -57 dBm |
| 64QAM | 3/4 | -65 dBm | -62 dBm | -59 dBm | -56 dBm |
| 64QAM | 5/6 | -64 dBm | -61 dBm | -58 dBm | -55 dBm |
| 256QAM | 3/4 | -59 dBm | -56 dBm | -53 dBm | -50 dBm |
| 256QAM | 5/6 | -57 dBm | -54 dBm | -51 dBm | -48 dBm |
| 1024QAM | 3/4 | -54 dBm | -51 dBm | -48 dBm | -45 dBm |
| 1024QAM | 5/6 | -52 dBm | -49 dBm | -46 dBm | -43 dBm |
Other Receiver Tests
Other 11ax receiver tests include adjacent and non-adjacent channel rejection, and receiver maximum input level.
References
- IEEE 802.11ax standard and WLAN 11ax conformance specifications
