I think the issues you mention are mostly just a matter of differing perspectives. The author starts from the perspective that the underlying signals are all fu

I think the issues you mention are mostly just a matter of differing perspectives. The author starts from the perspective that the underlying signals are all fundamentally complex, and a real signal (the projection of the 'true' signal onto the real axis, or upconverted complex baseband) is transmitted for physical convenience (i.e. possible to build). It sounds like you start from the perspective that the underlying signals are real, and the "artificial" analytic signal is only introduced as a mathematical convenience ("negative frequencies do not exist!"). IMO either perspective is fine - neither is "wrong" or "right." > because it's hard to determine the power (not even sure what he/she means there) I think they are referring to the fact that having the analytic representation makes envelope detection trivial.