The formula is #19 on page 3 and basically it is this:. I've been having a little look on this and there is a simpler formula you can use based on this document. There is a standard formula for calculating minimum theoretical signal level needed by a receiver for a given data rate. It gives an indication of likely bit error rates for instance. Fade Margin level is 14dB or lowerįade margin is the difference in power levels between the actual signal hitting the receiver and the bottom-line minimum signal needed by the receiver to work. Normal: Link would not be stable all the time, but should work properly. Good: Link should give you a good surfing experience. Notes from: suggest that fade margin varies from 14dB to 22dB Excellent: Link should work with high reliability, ideal for applications demanding high link quality. I have an Ralink RT5370 chipset wifi dongle with this specification: Ralink 5370 spec Pr = Signal power (dBm) at distance - Get this value by testingį = signal frequency in MHz - 2412~2483.5 MHz for Ralink 5370īut I am not able to figure out how to calculate the fade margin.īased on some findings, fade margin = sensitivity of receiver - received signalīut then again, how do I get sensitivity of the receiver? Po = Signal power (dBm) at zero distance - Get this value by testing N = Path-Loss Exponent, ranges from 2.7 to 4.3 The relationship b/w RSSI and Distance is ( source PPT): This part might be solved via this solution: Trilateration using 3 latitude and longitude points, and 3 distances Then do trilateration to pinpoint the location of the wifi signal.Compute distance based on RSSI (I understand this won't be 100% accurate).I am working on an indoor positioning system where I need to:
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