Viterbi Algorithm goes quantum

Alice would like to transmit a stream of quantum information to Bob. She shares entanglement in the form of ebits before quantum communication begins. Red qubits belong to Alice and blue qubits belong to Bob. She repeatedly performs a series of encoding operations and transmits her qubits as soon as they are encoded. The noisy quantum communication channel corrupts her transmitted qubits. Bob receives her qubits and combines them with his half of the ebits. He performs measurements and Viterbi processing of the measurement results to diagnose the channel errors and performs recovery operations based on the results of the Viterbi algorithm. He then performs a decoding circuit and finally possesses the qubits that Alice first sent. Credit: USC Viterbi School of Engineering