Rate Loss in Quantum Channels with Classical State and Applications for Quantum Broadcast Channels

Igor Bernard; Arun Padakandla

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arXiv · 2606.07409

Rate Loss in Quantum Channels with Classical State and Applications for Quantum Broadcast Channels

Igor Bernard·Arun Padakandla

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Abstract

We consider the problem of \textit{rate loss} - a strict penalty suffered in achievable rates due to the lack of channel state information at the receiver (Rx) of a classical-quantum (CQ) channel. First, we identify non-commutative CQ channels and analytically prove a rate loss. Building on this, we next prove that coset-code-based strategies can strictly outperform conventional unstructured IID-code-based strategies for non-commutative 3-user CQ broadcast channels.

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Igor Bernard, Arun Padakandla. 2026-06-05. Rate Loss in Quantum Channels with Classical State and Applications for Quantum Broadcast Channels. https://arxiv.org/abs/2606.07409

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