TY - GEN
T1 - A carrier frequency offset estimation scheme based on a scalar extended Kalman filter for uplink OFDM systems
AU - Zeng, Xiang Nian
AU - Ghrayeb, Ali
PY - 2008
Y1 - 2008
N2 - This paper proposes an extended Kalman filter (EKF)-based and training symbol aided carrier frequency off-set (CFO) estimation scheme for the uplink OFDM systems. Typically, in EKF-based estimation scheme, the measurement equation is a function of the CFO and channel coefficients. Therefore, a vector EKF has to be employed to estimate all the unknowns, which may sometime result in convergence problems. To avoid these problems, the proposed scheme uses a scalar EKF. The user signals are first separated by using multiple-access interference cancellation. Then, the unknown channel coefficients in the measurement equation are replaced with a non-linear function of the CFO so that the scalar EKF can be employed. The observation noise power is analyzed and its approximation is used in the EKF algorithm. Several numerical examples are presented to validate the efficacy of the proposed scheme. It is shown that the proposed scheme can achieve the Cramer-Rao lower bound (CRLB) when the number of users is small, whereas it degrades when the number of users increases. We also compare its computational complexity with several existing schemes.
AB - This paper proposes an extended Kalman filter (EKF)-based and training symbol aided carrier frequency off-set (CFO) estimation scheme for the uplink OFDM systems. Typically, in EKF-based estimation scheme, the measurement equation is a function of the CFO and channel coefficients. Therefore, a vector EKF has to be employed to estimate all the unknowns, which may sometime result in convergence problems. To avoid these problems, the proposed scheme uses a scalar EKF. The user signals are first separated by using multiple-access interference cancellation. Then, the unknown channel coefficients in the measurement equation are replaced with a non-linear function of the CFO so that the scalar EKF can be employed. The observation noise power is analyzed and its approximation is used in the EKF algorithm. Several numerical examples are presented to validate the efficacy of the proposed scheme. It is shown that the proposed scheme can achieve the Cramer-Rao lower bound (CRLB) when the number of users is small, whereas it degrades when the number of users increases. We also compare its computational complexity with several existing schemes.
UR - http://www.scopus.com/inward/record.url?scp=51249084971&partnerID=8YFLogxK
U2 - 10.1109/ICC.2008.112
DO - 10.1109/ICC.2008.112
M3 - Conference contribution
AN - SCOPUS:51249084971
SN - 9781424420742
T3 - IEEE International Conference on Communications
SP - 568
EP - 572
BT - ICC 2008 - IEEE International Conference on Communications, Proceedings
T2 - IEEE International Conference on Communications, ICC 2008
Y2 - 19 May 2008 through 23 May 2008
ER -