Problem
Problem
I have two USRP antennas close to each other. I know that signal strength on the receiving end has to be at least -80dBm. Both antennas have 2dBi of gain. I want to compute what is maximum propagation loss so that this system still works. Signal is being transmitted with power of 10mW.I have two USRP antennas close to each other. I know that signal strength on the receiving end has to be at least -80 dBm. Both antennas have 2 dBi of gain. I want to compute what is maximum propagation loss so that this system still works. Signal is being transmitted with power of 10 mW.
Attempt to solve
Attempt to solve
Since i want to know the maximum amount of power loss during transmission to one antenna to another. I can form equation as. $p_0=$ power of transmitted signal, $p_{m}$ =$p_{m}=$ minimum acceptable signal strength, $x=$ maximum amount of signal loss during transmission. $$ p_0 \cdot x = p_{\text{ml}} $$ $$ x = \frac{p_0}{p_{ml}} $$
My solution is ratio of powers so iI can use dB units, by converting them with 10base-base10 logarithm.
$$ x_{dB}=10\dot \log_{10}(\frac{p_0}{p_{ml}}) $$$$ x_{dB}=10\cdot \log_{10}\left(\frac{p_0}{p_{ml}}\right)$$
i need to change $-80$-80 dBm to millli watsmillliWatts with $-80$dBm$=10^{-80/10}$mW$-80\text{ dBm}=10^{-80/10}\text{ mW}$. After this iI can sum antenna gain to my answer since we are using logarithms.
$$ x_{dB}=10\log_{10}(\frac{10^{-80/10}\text{mW}}{10\text{mW}})+2\text{dBi} +2\text{dBi}$$$$ x_{dB}=10\log_{10}\left(\frac{10^{-80/10}\text{ mW}}{10\text{ mW}}\right)+2\text{ dBi} +2\text{ dBi}$$
$$ x_{dB}=-86\text{dB} $$$$ x_{dB}=-86\text{ dB} $$
However my answer seems to be incorrect ?
