Title :
Proposal of Channel Estimation Method for Bi-Directional OFDM Based ANC in Higher Time-Varying Fading Channel
Author :
Mata, Tanairat ; Naito, Katsuhiro ; Mori, Kazuo ; Boonsrimuang, Pisit ; Kobayashi, Hideo
Author_Institution :
Grad. Sch. of Eng., Mie Univ., Tsu, Japan
Abstract :
Broadband Analog Network Coding (ANC) based on OFDM has been widely investigated to increase capacity of bi-directional relay communications. The broadband ANC based on OFDM technique is required to estimate channel frequency responses (CFRs) between both user terminals (UTs) and a relay station (RS) precisely so as to remove the self-information data from the received signal and to demodulate the other user´s information data with frequency equalization. Many channel estimation methods have been proposed for the OFDM based broadband ANC. However bit error rate (BER) performance of these methods would be degraded relatively in higher time- varying fading channels due to the inaccurate estimation of CFR. To solve this problem, this paper proposes a CFR estimation method which can achieve better BER performance with keeping higher transmission efficiency even in higher time-varying fading channels. The salient features of proposed CFR estimation method are to enable the estimation of combined CFR at the UT for both channels between the UTs and RS by using scattered pilot subcarriers and to enable the demodulation of information data without feedback information of CFR estimated at the RS. This paper presents various simulation results in the higher time-varying fading channels to demonstrate the effectiveness of proposed CFR estimation method for the bi-directional OFDM based ANC.
Keywords :
OFDM modulation; channel estimation; error statistics; fading channels; network coding; relay networks (telecommunication); time-varying channels; bidirectional OFDM; bidirectional relay communications; bit error rate; broadband analog network coding; channel estimation method; channel frequency responses; frequency equalization; higher time-varying fading channel; relay station; scattered pilot subcarriers; user terminals; Bidirectional control; Bit error rate; Channel estimation; Estimation; Fading; OFDM; Relays;
Conference_Titel :
Vehicular Technology Conference (VTC Spring), 2014 IEEE 79th
Conference_Location :
Seoul
DOI :
10.1109/VTCSpring.2014.7023062