Cramer–Rao Lower Bound for Estimating Quadrupole Resonance Signals in Non-Gaussian Noise

Calculation of Differential Entropy for a Mixed Gaussian Distribution

“…Wang and Wu [6] considered a mixed-Gaussian noise model in a nonlinear signal detection application. Mixed Gaussian noise was also used for modeling purposes in Tan et al [7]. Additional works on mixed Gaussian noise include that of Bhatia and Mulgrew [5], who looked at a non-parametric channel estimator for this type of noise, and Lu [8], who looked at entropy regularized likelihood learning on Gaussian mixture models.…”

An Overview of NQR Signal Detection Algorithms

“…,t N−1 denotes the sampling time, measured with respect to the center of the refocusing pulse and typically starting at t 0 = 0 to allow for the deadtime between the pulse and the first measured sample; α k , β k , η k , and ω k (T ) denote the complex amplitude, the sinusoidal damping constant, the echo-train damping constant, and the temperature dependent frequency shifting function of the kth sinusoid, respectively. Moreover, w m (t) denotes an additive colored noise, which often can be modeled using a low order autoregressive model [11,12]. It is important to note that the number of sinusoids, d, and the frequency shifting function, ω k (T ), can generally be assumed to be known.…”

Advances in the engineering of quadrupole resonance landmine detection systems

“…The unwanted RFI is to a significant degree rejected by the design of the QR coil, but is also measured independently by additional reference antennas. Data from the reference antennas is processed and used to remove RFI signals from the data collected by the QR detection coil 13,[20][21][22] . The RFI-mitigated signal is then analyzed to determine whether a mine is present.…”