TY - JOUR
T1 - A study of pilot-assisted ofdm channel estimation methods with improvements for DVB-T2
AU - Yu, Mingchao
AU - Sadeghi, Parastoo
PY - 2012
Y1 - 2012
N2 - We provide a comparative study of channel estimation methods for pilot-assisted orthogonal frequency-division multiplexing (OFDM) communication systems in time-varying frequency-selective fading channels. We also propose an improved low-complexity least-squares (LS) estimation method based on the domain-transform process, which estimates time-domain channel impulse response (CIR) using the LS estimate of pilot subchannels. Our method is particularly suited to commercial OFDM systems such as the second generation of digital terrestrial television broadcasting systems (DVB-T2) because it has the following properties: 1) It uses only one OFDM symbol; 2) it does not require knowledge of channel statistics; 3) it works for any pilot pattern; and 4) the size of the estimation matrix for obtaining CIR only depends on the number of pilot subcarriers, but not on the size of OFDM symbol. Because of the first three properties, our method is robust to high Doppler frequency shifts, timing synchronization errors, and pilot patterns in commercial systems. Moreover, through computer simulations, we verify that our method provides competitive bit error rate and channel estimation error performance, compared with some well-known methods, which suffer from either a much higher computational load or less robustness to Doppler shifts or timing errors. For irregular pilot patterns, efficient yet simple regularization methods are suggested to solve the ill-conditioned problem of the estimation matrix. An upper bound on the mean squared error of the estimated CIR is also provided.
AB - We provide a comparative study of channel estimation methods for pilot-assisted orthogonal frequency-division multiplexing (OFDM) communication systems in time-varying frequency-selective fading channels. We also propose an improved low-complexity least-squares (LS) estimation method based on the domain-transform process, which estimates time-domain channel impulse response (CIR) using the LS estimate of pilot subchannels. Our method is particularly suited to commercial OFDM systems such as the second generation of digital terrestrial television broadcasting systems (DVB-T2) because it has the following properties: 1) It uses only one OFDM symbol; 2) it does not require knowledge of channel statistics; 3) it works for any pilot pattern; and 4) the size of the estimation matrix for obtaining CIR only depends on the number of pilot subcarriers, but not on the size of OFDM symbol. Because of the first three properties, our method is robust to high Doppler frequency shifts, timing synchronization errors, and pilot patterns in commercial systems. Moreover, through computer simulations, we verify that our method provides competitive bit error rate and channel estimation error performance, compared with some well-known methods, which suffer from either a much higher computational load or less robustness to Doppler shifts or timing errors. For irregular pilot patterns, efficient yet simple regularization methods are suggested to solve the ill-conditioned problem of the estimation matrix. An upper bound on the mean squared error of the estimated CIR is also provided.
KW - Channel estimation
KW - digital terrestrial television broadcasting system (DVB-T2)
KW - orthogonal frequency-division multiplexing (OFDM)
UR - http://www.scopus.com/inward/record.url?scp=84862625034&partnerID=8YFLogxK
U2 - 10.1109/TVT.2012.2195041
DO - 10.1109/TVT.2012.2195041
M3 - Article
SN - 0018-9545
VL - 61
SP - 2400
EP - 2405
JO - IEEE Transactions on Vehicular Technology
JF - IEEE Transactions on Vehicular Technology
IS - 5
M1 - 6187753
ER -