  Threshold effects in the estimation of parameters of non-linearly modulated,
continuous-time, wide-band waveforms, are examined from a statistical physics
perspective. These threshold effects are shown to be analogous to phase
transitions of certain disordered physical systems in thermal equilibrium. The
main message, in this work, is in demonstrating that this physical point of
view may be insightful for understanding the interactions between two or more
parameters to be estimated, from the aspects of the threshold effect.
