  The standard quantum state discrimination problem can be understood as a
communication scenario involving a sender and a receiver following these three
steps: (i) the sender encodes information in pre-agreed quantum states, (ii)
sends them over a noiseless channel, and (iii) the receiver decodes the
information by performing appropriate measurements on the received states. In a
practical setting, however, the channel is not only noisy but often also
unknown, thus altering the states and making optimal decoding generally not
possible. In this work, we study this noisy discrimination scenario using a
protocol based on indefinite causal order. To this end, we consider the quantum
switch and define its higher-order generalisations, which we call
superswitches. We find that, for certain channels and ensembles, the guessing
probability can be significantly improved compared to both single- and
multi-copy state discrimination.
