Pilot-Based Channel Estimation for AF Relaying Using Energy Harvesting

Abstract

Ning. (2017) Pilot-based channel estimation for AF relaying using energy harvesting. IEEE Transactions on Vehicular Technology . Permanent WRAP URL:http://wrap.warwick.ac.uk/85078 Copyright and reuse:The Warwick Research Archive Portal (WRAP) makes this work by researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available.Copies of full items can be used for personal research or study, educational, or not-for profit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way.Publisher's statement: © 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. A note on versions:The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP url' above for details on accessing the published version and note that access may require a subscription. Abstract-In existing channel estimators for amplify-andforward relaying, pilots are often sent from the relay to the destination which consumes the relay's own energy. This limits the relay's participation in the network. In this paper, several moment-based channel estimators for amplify-and-forward relaying are proposed that harvest energy from the source and using the harvested energy to send pilots to the destination for channel estimation. Both time-switching and power-splitting strategies are considered. Numerical results show that the two schemes that perform channel estimation only at the destination have worse performances than the two schemes that perform channel estimation at both the relay and the destination. They also show that the bit error rate performances of all schemes are close to the perfect case when exact knowledge of the channel state information is available such that there is no channel estimation error in the demodulation. The assumption that the two schemes only perform channel estimation at the destination makes them simpler, as they do not require channel estimation at the relay or feed the channel estimate back to the destination.

Novel Energy-Harvesting AF Relaying Schemes With Channel Estimation Errors

“…The received data in ( 11) is sent to the destination by using the transmission power of the relay in (12) and the channel estimate in (13). Thus, the amplification factor can be written asâ…”

“…The data packet in the second hop contains channel estimation and information decoding. Compared with the previous works, the main difference between this work and [12] is that [12] considered TS and PS separately, while this work considers different combinations of TS and PS simultaneously. Compared with [13], this work includes channel estimation and information decoding and the harvested energy is used for both information decoding and channel estimation, while [13] only considered channel estimation.…”

“…In [2], two different energy harvesting protocols have been proposed: power-splitting (PS) and time-switching (TS). The harvest-use structures were used for either TS or PS in [12]. In [13], more advanced energy harvesting structures have been discussed, where the authors analyzed the rateenergy tradeoff for wireless information and power transfer.…”

Delay constrained throughput optimization in multi-hop AF relay networks, using limited quantized CSI

“…Constants α i−1 and α i are set at the start of the communication, and SINRs are estimated from the received signal. AF relay-based transmission is usually divided into two phases, including channel estimation through broadcasting of training information and retransmission of information to the destination [47,48]. In time division duplex (TDD) transmission, the i-th relay can reliably estimate s i−1 from the training information of (i − 1)-th relay and s i can be acquired through eavesdropping of the training information in channel estimation phase of (i + 1)-th relay.…”

Evaluation of Hybrid Dedicated/Ambient EH for AF Relaying

“…Current thinking in the community is dominated by either considering the systems with relay RF ambient EH and channel estimation without data transmission [6], or relay merely harvested energy from the source without examining the ambient energy [7]. In [8], the average output DC power in ambient RF energy harvesting has been analyzed through the effects of antenna directivity and antenna port number.…”