Yes, except you are counting the 3 dB twice. If you look at it from the total power perspective, signal stays the same, noise is cut in half. If you look at it from the power spectral density perspective, signal is double, noise stays the same.
In some bands the regulatory limit is on psd not total power, so you don’t gain any system margin with a narrower channel, you just lose throughput. From: Forrest Christian (List Account) Sent: Thursday, June 16, 2016 9:18 AM To: af Subject: [AFMUG] Power limits per hertz. I've had a couple of conversations over the past little bit which has gotten me thinking about power limits in relation to channel width. This is my thinking. Assume 5.8ghz, ap side. Power limit 36dbm. My question/thought/potential misunderstanding has to do with how that 36dbm is measured. Assuming you're comparing a 20 mhz channel with a 10 mhz channel, both at EIRP limits, does the 10 mhz channel effectively have more Power density? Assuming this is the case, it seems you would gain 3db of link margin for the increased power density and 3db more for reduced noise floor. 6db is double the distance which is big, even with the reduced throughput. Is this the way this works?
