Abstract
Abstract In this paper, we consider the linear minimum mean square error (LMMSE) estimation of channel for the two-way relay network employing analog network coding and orthogonal frequency division multiplexing. The channel responses required for self-interference cancelation and coherent detection are estimated in the time domain with the preamble. We derive the optimal training condition for minimizing the mean square error (MSE) of the LMMSE estimator and obtain the corresponding MSE. It is observed that the LMMSE estimator has the optimal training condition equivalent to that of the least square estimator and that the former is less sensitive to the training sequences than the latter. We also propose new training sequences not only satisfying the optimal training condition but also providing the minimum peak-to-average power ratio.
Highlights
Relay communication has been intensively studied so far due to its capability of improving coverage and reliability at low cost [1,2,3]
5 New sets of optimal training sequences In Appendix 2, we have provided a derivation of the least square (LS) estimator and its optimal training condition to minimize the mean square error (MSE), where we have shown the equivalence of the optimal training conditions for the linear minimum mean square error (LMMSE) and LS estimators
We have derived the conditions for optimal training sequences minimizing the MSE of the LMMSE estimator, which is found out to be equivalent to the optimal training conditions of the LS estimator
Summary
Relay communication has been intensively studied so far due to its capability of improving coverage and reliability at low cost [1,2,3]. It should be mentioned that the former requires the feedback of channel estimates from the relay for the communication nodes to perform SIC and coherent detection To avoid such a feedback, the latter estimates the composite channels of the MAC and BC phases as in the channel estimators developed for the OFDM-based TWR networks with channel reciprocity [10,11,13]. The linear minimum mean square error (LMMSE) estimator is adopted for the improvement of channel estimation of OFDM-based TWR networks employing ANC.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: EURASIP Journal on Wireless Communications and Networking
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
