The rate performance of wireless coded caching schemes is typically limited by the lowest achievable per-user rate in the given multicast group, during each transmission time slot. In this paper, we provide a new coded caching scheme, alleviating this worst-user effect for the prominent case of multimedia applications. In our scheme, instead of maximizing the symmetric rate among all served users, we maximize the total quality of experience (QoE); where QoE at each user is defined as the video quality perceived by that user. We show the new scheme requires solving an NP-hard optimization problem. Thus, we provide two heuristic algorithms to solve it in an approximate manner; and numerically demonstrate the near-optimality of the proposed approximations. Our approach allows flexible allocation of distinct video quality for each user, making wireless coded caching schemes more suitable for real-world implementations.
Salehi Mohammad Javad, Tölli Antti, Shariatpanahi Seyed Pooya
A4 Article in conference proceedings
Place of publication:
21st IEEE International Workshop on Signal Processing Advances in Wireless Communications, SPAWC 2020
3 August 2020
M. Salehi, A. Tölli and S. P. Shariatpanahi, “Coded Caching with Uneven Channels: A Quality of Experience Approach,” 2020 IEEE 21st International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Atlanta, GA, USA, 2020, pp. 1-5, doi: 10.1109/SPAWC48557.2020.9154234
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