TY - GEN
T1 - Robust uplink carrier frequency offset estimation with interference mitigation in OFDMA systems
AU - Zhang, Zhongshan
AU - Kayama, Hidetoshi
PY - 2006
Y1 - 2006
N2 - In Orthogonal Frequency-Division Multiplexing Access (OFDMA) systems, Multiple-User-Interference (MUI) between different subscribers due to their non-zero carrier frequency offsets may deteriorate their BER performance greatly. Instantaneously large carrier frequency offset of one subscriber will contribute a heavy interference to its frequencydomain neighbors. MUI not only reduces the effective Signal-to-Interference-plus-Noise Ratio (SINR), but sometimes introduces a bias to carrier frequency offset estimators of each subscriber. In this paper, uplink carrier frequency offset estimation in OFDMA systems is discussed. The estimation accuracy of one estimator benefits from an effective MUI elimination/reduction. In the following sections, after analyzing the negative effect of MUI on uplink carrier frequency offset estimation, we will give out some interference reduction/elimination methods in OFDMA systems. Cramer-Rao Lower Bound (CRLB) for an unbiased carrier frequency offset estimator in a Multi-Access (MA) system is derived in this paper. A new training sequence group named Round-Robin Training Sequence Group (RRTSG), is also proposed to perform uplink synchronization. It outperforms conventional training sequences with respect to higher interference mitigation/reduction capability.
AB - In Orthogonal Frequency-Division Multiplexing Access (OFDMA) systems, Multiple-User-Interference (MUI) between different subscribers due to their non-zero carrier frequency offsets may deteriorate their BER performance greatly. Instantaneously large carrier frequency offset of one subscriber will contribute a heavy interference to its frequencydomain neighbors. MUI not only reduces the effective Signal-to-Interference-plus-Noise Ratio (SINR), but sometimes introduces a bias to carrier frequency offset estimators of each subscriber. In this paper, uplink carrier frequency offset estimation in OFDMA systems is discussed. The estimation accuracy of one estimator benefits from an effective MUI elimination/reduction. In the following sections, after analyzing the negative effect of MUI on uplink carrier frequency offset estimation, we will give out some interference reduction/elimination methods in OFDMA systems. Cramer-Rao Lower Bound (CRLB) for an unbiased carrier frequency offset estimator in a Multi-Access (MA) system is derived in this paper. A new training sequence group named Round-Robin Training Sequence Group (RRTSG), is also proposed to perform uplink synchronization. It outperforms conventional training sequences with respect to higher interference mitigation/reduction capability.
UR - http://www.scopus.com/inward/record.url?scp=34250374509&partnerID=8YFLogxK
U2 - 10.1109/WCNC.2003.1200476
DO - 10.1109/WCNC.2003.1200476
M3 - Conference contribution
AN - SCOPUS:34250374509
SN - 0780377001
SN - 1424402700
SN - 9781424402700
T3 - IEEE Wireless Communications and Networking Conference, WCNC
SP - 816
EP - 821
BT - 2006 IEEE Wireless Communications and Networking Conference, WCNC 2006
T2 - 2006 IEEE Wireless Communications and Networking Conference, WCNC 2006
Y2 - 3 April 2006 through 6 April 2006
ER -