Fig. 9

Mean square error (MSE) \(\frac {1}{N}\sum _{n=0}^{N-1} |x(t_{n})-s(\hat {\boldsymbol {\theta }}, t_{n})|^{2}\) as a function of the number of iterations of the trust-region-reflective algorithm (estimation phase only). Different SNR values are considered and the last point of each curve indicates the convergence of the algorithm