I am using the IQ values collected from the Channel Sounding example. The data in the 0 section seems to indicate that this channel is not in use?

RE: I am using the IQ values collected from the Channel Sounding example. The data in the 0 section seems to indicate that this channel is not in use?

Simonr — Thu, 06 Nov 2025 07:44:59 GMT

The frequencies used by channel sounding are defined in the BLE spec and use a set of 72 channels spaced 1MHz apart, so if these channels are in increasing order, there should be 4MHz between these channels, correct. I assume this frequency range is jammed or of poor quality in your testing environment.

Best regards,

Simon

RE: I am using the IQ values collected from the Channel Sounding example. The data in the 0 section seems to indicate that this channel is not in use?

a9876 — Wed, 05 Nov 2025 09:10:17 GMT

My primary concern is the channel spacing. For example, if there are three channels skipped in the middle, The spacing between the channels immediately before and after these three channels is 4 MHz?

RE: I am using the IQ values collected from the Channel Sounding example. The data in the 0 section seems to indicate that this channel is not in use?

Simonr — Wed, 05 Nov 2025 09:02:43 GMT

If you're looking at the IQ values from the cs_de_report_t, our guess is that you're hitting the following condition for some channels here. This means that the controller believes the measurement on a channel of not good quality due to interference for example. The solution we have in cs_de.c by default ignores measurements on these channels and leave IQ values at 0.

Best regards,

Simon

RE: I am using the IQ values collected from the Channel Sounding example. The data in the 0 section seems to indicate that this channel is not in use?

a9876 — Mon, 03 Nov 2025 12:23:18 GMT

The channel spacing frequency before and after these three 0 data points is 4 MHz?

RE: I am using the IQ values collected from the Channel Sounding example. The data in the 0 section seems to indicate that this channel is not in use?

Susheel Nuguru — Mon, 03 Nov 2025 09:51:29 GMT

Hi,

The person who has more knowledge on the channel sounding is away today and hopefully be back tomorrow.

But I can give you some response to your question.

[quote user=""]For example, as shown in the picture, the three IQ data in the middle are all 0. So, is the frequency of the channels before and after these three data values 4 MHz different?[/quote]

The zeros are empty T_PM measurements, not real IQ at a valid tone. The The mid-array zeros does not seem to be real 0-amplitude channels, they seem to be placeholders where no phase sample was taken.