Hyperparameter Free MEE-FP based Learning for Next Generation
Communication Systems
Abstract
Information theoretic learning (ITL) criteria have emerged useful for
mitigating degradations caused by unknown non-Gaussian noise processes
in future wireless communication systems. Specifically, the reproducing
kernel Hilbert space (RKHS) based approaches relying on ITL based
learning criteria are envisioned to provide nearoptimal mitigation of
unknown hardware impairments and non-Gaussian noises. Among several ITL
criteria, the recent works find the minimum error entropy with fiducial
points (MEE-FP) promising due to its guarantee of unbiased estimation
and generalization over generic noise distributions. However, MEE-FP
based learning approaches are known to depend on an accurate
kernel-width initialization. Also, the optimal value of this kernelwidth
is well-known to vary temporally and across deployment scenarios. To
remove the dependency on kernelwidth, a hyperparameter-free MEE-FP based
adaptive algorithm is derived using random-Fourier features with sampled
kernel widths (RFF-SKW). In addition, a detailed convergence analysis is
presented for the proposed hyperparameter-free MEE-FP, which promises a
near-optimal error-floor independent of step-size and guarantees
convergence for a wide range of step sizes. The promised
hyperparameter-independence and improved convergence for the proposed
hyperparameter-free MEE-FP are validated by computer simulations
considering different case studies.