I need to do some data analysis on I/Q samples and was trying to know what are the parameters that determine the maximum/minimum values of these samples. In other words, what determines the maximum/minimum values set on the constellation diagram axes?
Does the type of the modulation scheme play a role? i.e., 64-QAM is expected to have constellation axes larger than that in 4-QAM ?
Does the energy in the symbols that these I/Q samples are mapping also play a role? i.e., a stream of symbols that have bits of voltage levels +5/-5 are expected to generate I/Q samples larger in value that a stream of symbols with bits of voltage levels +1/-1 ?
Does the power level that the transmitter is going to send the modulated signal with also play a role?
All the internet sources that I looked at always discuss how I/Q QAM modulation works and none of it provides quantitative explanations that could help me. The only image that I found having numbers on the axes is shown below:
It shows that for 64-QAM the max value of I/Q is 7 and for 4-QAM is 1. Is this just an illustration or how it actually works? Could I infer that for n-QAM, the max I/Q value is log2(n)+1 ?
In addition, I looked at some data-sets of I/Q samples and found that all samples lie in the range of -1 to +1 despite the fact that different modulation schemes were used. Is there a kind of normalization that's generally used that I am not aware of? If so, is there a method to convert them to their original values?
Also, are there related equations that could show how the max/min I/Q samples values are set?