  Machine learning methods adapt the parameters of a model, constrained to lie
in a given model class, by using a fixed learning procedure based on data or
active observations. Adaptation is done on a per-task basis, and retraining is
needed when the system configuration changes. The resulting inefficiency in
terms of data and training time requirements can be mitigated, if domain
knowledge is available, by selecting a suitable model class and learning
procedure, collectively known as inductive bias. However, it is generally
difficult to encode prior knowledge into an inductive bias, particularly with
black-box model classes such as neural networks. Meta-learning provides a way
to automatize the selection of an inductive bias. Meta-learning leverages data
or active observations from tasks that are expected to be related to future,
and a priori unknown, tasks of interest. With a meta-trained inductive bias,
training of a machine learning model can be potentially carried out with
reduced training data and/or time complexity. This paper provides a high-level
introduction to meta-learning with applications to communication systems.
