Low-Complexity Buffer-Aided Link Selection with Outdated CSI and Feedback Errors

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Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Degree programme
3694 - 3706
IEEE Transactions on Communications, Volume 66, issue 8
Buffer-aided relays can improve the diversity of multi-hop networks, however, they increase packet delays. Thus, various delay-aware protocols have been developed, but without considering the transmission diversity. Moreover, most works adopt ideal assumptions, such as symmetric links, perfect Channel State Information (CSI) and error-free feedback channels. So, we propose a Low-Complexity (LoCo) link selection algorithm, herein called LoCo - Link. The proposed algorithm may experience delays during CSI updates, and hence, by using outdated CSI its performance may deteriorate. To alleviate this issue, we next propose a distributed version of LoCo - Link (d - LoCo - Link) dealing with outdated CSI. In both algorithms, the source performs broadcasting towards multiple relays; when the packets are transmitted by a relay to the destination, they are discarded from all other relays. This coordination relies on feedback channels. For non error-free feedback channels, we propose a scheme in which the relays listen to the transmission of the best relay and drop duplicate packets. Results show that LoCo - Link surpasses other algorithms, by decreasing the delay in asymmetric networks. Moreover, d - LoCo - Link avoids diversity losses due to outdated CSI, while the effect of non error-free feedback channels is mitigated by taking advantage of the inter-relay channels.
asymmetric links, Broadcasting, buffer-aided relaying, delay, Delays, diversity, Diversity reception, low-complexity, Markov chains, non error-free feedback, outdated CSI, Protocols, Relay networks (telecommunications), Relay selection, Signal to noise ratio
Other note
Nomikos, N, Charalambous, T, Vouyioukas, D & Karagiannidis, G K 2018, ' Low-Complexity Buffer-Aided Link Selection with Outdated CSI and Feedback Errors ', IEEE Transactions on Communications, vol. 66, no. 8, pp. 3694 - 3706 . https://doi.org/10.1109/TCOMM.2018.2821143