# Calculate power of an LTE Signal

I am looking for the formula to convert the power level of an OFDM RF signal to an absolute power level. For example if I have my typical rectangular RF spectrum and the bandwidth of the signal is 10MHz, if my signal power needs to be 23dBm, what power do I need to measure on the plateau of the rectangular OFDM signal?

For example I saw a measurement function in a spectrum analyser where you could bring up markers and it would give an RF power level measured across that bandwidth, I remember seeing the waveform peak at about -20dBm but integrated across the bandwidth the power level came out to be around 1dBm.

I would like to know the formula. if I know the bandwidth of my OFDM signal and know what power level i need to reach, what level should I measure at the peak of my RF signal?

• If you're done with this question and answer please formally accept the answer or raise another comment for further clarification. – Andy aka Aug 4 at 9:51

$$\text{real power} = 10^{\frac{23}{10}} = 200 \text{ mW}$$
$$20 \text{ nano watts per Hz}$$ $$= -77 \text{ dBW per Hz}$$ $$= -47 \text{ dBm per Hz}$$