WaveJudge Wi-Fi 7 Demo

Welcome to a demonstration using Keysight’s WaveJudge wireless analyzer to capture, decode, and analyze Wi-Fi 7 signals.

We are using the UXM to simulate 25 clients along with an AP as the Wi-Fi network. WaveJudge passively captures the Wi-Fi traffic between the AP and the UXM. The WLT application software with its extensive configurability is used to simulate the Wi-Fi 7 network.

The flexible user interface of the WaveJudge is used to configure the RF ports of the WaveJudge hardware for capturing the traffic. The cell is configured as Wi-Fi 7. We are testing at a frequency of 5.21 GHz, in the 6 GHz band that was newly defined for use with Wi-Fi 6E. Today, we are doing a short capture of Wi-Fi 7 traffic, but several minutes of data may be captured, if desired. We are storing the captured data on the SSD card in the WaveJudge hardware.

WaveJudge quickly captures, stores, and decodes the Wi-Fi 7 traffic leading to a display of lower and upper layer messages along with RF charts derived from the captured IQ data.

You can see the messages for each captured frame along with many other parameters such as MIMO layer, MCS, and modulation type and the station ID of the client communicating with the AP. We are transmitting at MCS 13 using 4096QAM, to multiple clients.

WaveJudge has automatic error checking so you can quickly identify areas where more investigation is needed.

Let’s look at the RF charts in more detail. Identifying potential issues is simple since each chart’s results are correlated with the message selected in the messages list.

The EVM constellation shows the individual constellation points of each transmission. You can configure each RF chart to show the independent MIMO layers.

The 2D power chart is a unique graphical depiction of the power in each subcarrier in the time-frequency plane. You can see subcarrier power and subcarrier type to investigate transmission patterns.

The time domain power chart includes powerful options to display instantaneous and average power, as well as noise floor and full scale to help with troubleshooting.

The summary chart shows detailed RF information such as frequency and bandwidth, and also EVM, blur, and average and peak throughput. You can also see this same RF information for each AP and client.

The EVM per subcarrier chart is a powerful tool for troubleshooting errors in modulation performance. The average and peak EVM of each subcarrier are displayed graphically making it easy to see the outliers in performance.

This chart shows the calculated blur over time, useful to pinpoint throughput issues. The estimated frequency chart is useful for troubleshooting frequency errors. The spectral power chart shows the power of each subcarrier versus frequency. Each chart can be zoomed vertically or horizontally for more in-depth analysis.

Let’s look in more detail at the extensive troubleshooting capability of the WaveJudge Wi-Fi 7 solution. Each message is automatically checked for errors.

Here you can see the EVM performance of these subcarriers is not as expected and needs more investigation. In looking at the EVM per subcarrier plot in more detail, we can see one particular subcarrier’s peak and average EVM is much worse than the others. It is identified as subcarrier -447 with a peak EVM of -26 dB. To investigate further, let’s look at the EVM constellation chart. You can see that subcarrier -447 is outside the range of the expected 4096QAM constellation. It is possible that this performance is contributing to the error identified in the messages list.

For additional information, let’s look at the message parameters by opening the details from the messages list. This shows detailed decode information about each part of the message and identifies the specific areas where errors were detected. You can see that CW index 2 did not decode even after 15 iterations when the others were decoded after just 3 or 4. The maximum number of iterations can be increased to possibly decode the identified bits, but instead, let’s look in more detail at the message.

This view shows the bits and hexadecimal data for the entire message. In this case, it is the protected data where the error occurs. If we look at that in more detail, you can see WaveJudge identifies the exact hexadecimal data where the CRC error occurs.

WaveJudge analysis provides many clues to accelerate troubleshooting for Wi-Fi 7 and other technologies such as 5G NR NTN, C-IoT, V2X, and O-RAN.