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Channel power measurement

Started by LoganathanN 2 months ago2 replieslatest reply 1 month ago99 views

Hello All,

I need to implement a channel power measurement logic for the following reason. Actual problem statement is to detect the COMM radio activity (which last minimum 1mSec time) in the 20MHz - 100MHz frequency range. I need to detect Frequency Hoping (FH), Burst and Fixed Frequency (FF) communication activity in the stated frequency range

Interest is to detect analog handset or radio which is used modulate voice signal in to AM or FM. So, these radio may have bandwidth of 15KHz for FM and less than 5KHz for AM. 

For this, I chosen a FFT based logic to detect the signal activity. Resolution of the FFT is 6.25KHz (160uSec timing resolution). This resolution is sufficient to know the frequency and power level of the radio with the allowed tolerance. But, there are 5 or 6 FM station between 88 to 100 while opening the whole 20-100MHz band. I'm able to detect the all the FM stations properly and reporting as FF. But, I couldn't detect the exact power level since the energy spread over 24 FFT bins (150KHz/6.25KHz). Hence, I need to have a channel power measurement logic for this problem statement. 

I have gone through the below link to compute the channel power. 

https://signalhound.com/news/what-is-channel-power-and-occupied-bandwidth/

But it is working fine for CW signals and not for the BW occupied signals. I used hanning window in this implementation and the ENBW for the hanning window is 1.5. Please throw some insights for the given problem. Thanks in advance.

Regards

Loganathan

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Reply by neiroberOctober 21, 2022

Loganathan,

I wrote a post that includes a Matlab function to compute power over a band:

https://www.dsprelated.com/showarticle/1387.php

I'm not sure it applies to your situation, but take a look.

regards,

Neil


[ - ]
Reply by LoganathanNOctober 28, 2022

Hello Neil,

Thanks for the response. I'll look in to the article.

Regards,

Loganathan