Low-complexity channel estimation for OFDM systems in high-mobility fading channels


Yalcin M. , Akan A. , Dogan H.

TURKISH JOURNAL OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES, cilt.20, ss.583-592, 2012 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 20 Konu: 4
  • Basım Tarihi: 2012
  • Doi Numarası: 10.3906/elk-1101-1060
  • Dergi Adı: TURKISH JOURNAL OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES
  • Sayfa Sayıları: ss.583-592

Özet

Nowadays, multicarrier transmission is very popular because of the high data rate requirement of wireless systems. Orthogonal frequency-division multiplexing (OFDA) is a special case of multicarrier transmission. It is considered an effective technique for frequency-selective channels because of its spectral efficiency, its robustness in different multipath propagation environments, and its ability of combating intersymbol interference. Losing subchannel orthogonality causes interchannel interference, but, many conventional channel estimators assume that the channel is time-invariant during one OFDM symbol. This assumption causes error floors along the OFDM symbol for high-mobility cases. In this paper, we propose 2-dimensional pilot symbol-assisted channel estimation for wireless OFDM systems by using frequency and tune-domain interpolation. This method has the advantage of minimizing the system, complexity and processing delay while closely approximating the actual mobile channel. The performance of our proposed method is compared to coherent modulation with perfect channel estimation as well as other conventional channel estimation methods. Different detection techniques were used to test our proposed channel estimation algorithm.

Nowadays, multicarrier transmission is very popular because of the high data rate requirement of wireless

systems. Orthogonal frequency-division multiplexing (OFDM) is a special case of multicarrier transmission.

It is considered an effective technique for frequency-selective channels because of its spectral efficiency, its

robustness in different multipath propagation environments, and its ability of combating intersymbol interference.

Losing subchannel orthogonality causes interchannel interference, but many conventional channel

estimators assume that the channel is time-invariant during one OFDM symbol. This assumption causes

error floors along the OFDM symbol for high-mobility cases. In this paper, we propose 2-dimensional pilot

symbol-assisted channel estimation for wireless OFDM systems by using frequency and time-domain interpolation.

This method has the advantage of minimizing the system complexity and processing delay while

closely approximating the actual mobile channel. The performance of our proposed method is compared to coherent

modulation with perfect channel estimation as well as other conventional channel estimation methods.

Different detection techniques were used to test our proposed channel estimation algorithm.