A Low Complexity MMSE for OFDM Systems over Frequency-Selective Fading Channels
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IEEE COMMUNICATIONS LETTERS, VOL. 16, NO. 3, MARCH 2012
A Low Complexity MMSE for
OFDM Systems over Frequency-Selective Fading Channels
Tian-Ming Ma, Yu-Song Shi, and Ying-Guan Wang
Abstract—Channel estimation is one of the key technologies in
Orthogonal Frequency Division Multiplexing (OFDM) systems, which has received more and more consideration. A modified
Minimum Mean Square Error (MMSE) is proposed and simulated by MATLAB over a frequency-selective fading channel.
Comparing with the conventional MMSE, this algorithm has the advantage of low complexity. Meanwhile, it shows little attenuation of Mean Square Error (MSE) and Bit Error Rate
(BER) performances according to the final simulation results, which is promising for practical applications.
Notation: We use bold upper case letters to denote matrices and bold lower case letters to denote vectors. Furthermore,
(·)−1 is reserved for the matrix inverse and (·)H for Hermitian transposition. The estimated value of a variable a is denoted by a. I denotes an identity matrix, diag(v) denotes a
ˆ
diagonal matrix with diagonal elements given by the vector
v. · F denotes the Frobenius norm, E(·) is reserved for the mathematical expectation.
Index Terms—OFDM, channel estimation, frequency-selective fading channel.
II. S YSTEM M ODEL AND C HANNEL M ODEL
The data bits provided from the source are converted from serial to parallel to form parallel data after modulation. The modulated data with pilots insertion form N sub-carriers and each sub-carrier consists of data symbol X(k), where k represents the sub-carrier index. After the inverse fast Fourier transform (IFFT), the time-domain OFDM signal can be expressed as
I. I NTRODUCTION
FDM technology is a popular technique for transmission of signals over wireless channels, due to its many advantages such as the high spectral efficiency, robustness to frequency selective fading, and the feasibility of low-cost
transceiver
IEEE COMMUNICATIONS LETTERS, VOL. 16, NO. 3, MARCH 2012
A Low Complexity MMSE for
OFDM Systems over Frequency-Selective Fading Channels
Tian-Ming Ma, Yu-Song Shi, and Ying-Guan Wang
Abstract—Channel estimation is one of the key technologies in
Orthogonal Frequency Division Multiplexing (OFDM) systems, which has received more and more consideration. A modified
Minimum Mean Square Error (MMSE) is proposed and simulated by MATLAB over a frequency-selective fading channel.
Comparing with the conventional MMSE, this algorithm has the advantage of low complexity. Meanwhile, it shows little attenuation of Mean Square Error (MSE) and Bit Error Rate
(BER) performances according to the final simulation results, which is promising for practical applications.
Notation: We use bold upper case letters to denote matrices and bold lower case letters to denote vectors. Furthermore,
(·)−1 is reserved for the matrix inverse and (·)H for Hermitian transposition. The estimated value of a variable a is denoted by a. I denotes an identity matrix, diag(v) denotes a
ˆ
diagonal matrix with diagonal elements given by the vector
v. · F denotes the Frobenius norm, E(·) is reserved for the mathematical expectation.
Index Terms—OFDM, channel estimation, frequency-selective fading channel.
II. S YSTEM M ODEL AND C HANNEL M ODEL
The data bits provided from the source are converted from serial to parallel to form parallel data after modulation. The modulated data with pilots insertion form N sub-carriers and each sub-carrier consists of data symbol X(k), where k represents the sub-carrier index. After the inverse fast Fourier transform (IFFT), the time-domain OFDM signal can be expressed as
I. I NTRODUCTION
FDM technology is a popular technique for transmission of signals over wireless channels, due to its many advantages such as the high spectral efficiency, robustness to frequency selective fading, and the feasibility of low-cost
transceiver