TY - JOUR
T1 - Iterative frequency domain channel estimation for DFT-precoded OFDM systems using in-band pilots
AU - Lam, Chan Tong
AU - Falconer, David D.
AU - Danilo-Lemoine, Florence
N1 - Funding Information:
Manuscript received March 30, 2007; revised August 17, 2007. Part of this work has been performed in the framework of the IST project IST-4-027756 WINNER, which is partly funded by the European Union. The work reported here was funded by the Natural Sciences and Engineering Research Council (NSERC) of Canada. C.-T. Lam is currently with the Bureau of Telecommunications (DSRT) of Macao S.A.R., China (e-mail: [email protected]). D. Falconer is with Dept. of Systems and Computer Eng., Carleton University, Ottawa, ON, Canada (e-mail: [email protected]). F. Danilo-Lemoine is with Dept. of Systems and Computer Eng., Carleton University, Ottawa, ON, Canada (e-mail: [email protected]). Digital Object Identifier 10.1109/JSAC.2008.080211.
PY - 2008/2
Y1 - 2008/2
N2 - We consider two techniques of in-band frequency domain multiplexed (FDM) pilots using interleaved frequency domain multiple access (IFDMA) signal with a Chu sequence for DFT-precoded OFDM (or single-carrier (SC)) systems. One, called frequency domain superimposed pilot technique (FDSPT), superimposes pilot tones onto scaled or deleted data tones, which preserves spectral efficiency at the expense of a slight performance loss. The other, called frequency expanding technique (FET), multiplexes pilot tones by displacing data tones, which slightly reduces spectral efficiency. Using FDM pilots in SC systems facilitates flexible and efficient assignment of signals to available spectrum. We propose an iterative frequency domain decision-directed interference cancellation technique to reduce the intersymbol interference level of SC signals with FDSPT pilots (resulting from the suppression of data tones). Moreover, we propose a low complexity frequency domain iterative decisiondirected channel estimation (IDDCE) technique for SC systems using FDM pilots. Using IDDCE, the frame error rate (FER) performance for coded SC systems using FET and FDSPT pilots with interference cancellation is found to be about 0.2 dB and about 0.5 dB, respectively, away from the FER performance with known channel frequency response at FER=10-2. FDSPT pilots can also be used for OFDM systems with channel coding. It is found that an extra 1 dB of SNR is required at FER=10-2, compared with that using the conventional FET pilots for OFDM systems.
AB - We consider two techniques of in-band frequency domain multiplexed (FDM) pilots using interleaved frequency domain multiple access (IFDMA) signal with a Chu sequence for DFT-precoded OFDM (or single-carrier (SC)) systems. One, called frequency domain superimposed pilot technique (FDSPT), superimposes pilot tones onto scaled or deleted data tones, which preserves spectral efficiency at the expense of a slight performance loss. The other, called frequency expanding technique (FET), multiplexes pilot tones by displacing data tones, which slightly reduces spectral efficiency. Using FDM pilots in SC systems facilitates flexible and efficient assignment of signals to available spectrum. We propose an iterative frequency domain decision-directed interference cancellation technique to reduce the intersymbol interference level of SC signals with FDSPT pilots (resulting from the suppression of data tones). Moreover, we propose a low complexity frequency domain iterative decisiondirected channel estimation (IDDCE) technique for SC systems using FDM pilots. Using IDDCE, the frame error rate (FER) performance for coded SC systems using FET and FDSPT pilots with interference cancellation is found to be about 0.2 dB and about 0.5 dB, respectively, away from the FER performance with known channel frequency response at FER=10-2. FDSPT pilots can also be used for OFDM systems with channel coding. It is found that an extra 1 dB of SNR is required at FER=10-2, compared with that using the conventional FET pilots for OFDM systems.
KW - DFTprecoded OFDM
KW - Frequency domain channel estimation
KW - In-band pilots
KW - Iterative frequency domain equalization
KW - OFDM
KW - Single-carrier
UR - http://www.scopus.com/inward/record.url?scp=38849141591&partnerID=8YFLogxK
U2 - 10.1109/JSAC.2008.080211
DO - 10.1109/JSAC.2008.080211
M3 - Article
AN - SCOPUS:38849141591
SN - 0733-8716
VL - 26
SP - 348
EP - 358
JO - IEEE Journal on Selected Areas in Communications
JF - IEEE Journal on Selected Areas in Communications
IS - 2
ER -