# MIMO-OFDM CHANNEL ESTIMATION - A Pilot Sequence Design for Time-domain Processing

### Carlos Ribeiro, Atílio Gameiro

#### Abstract

A pilot sequence design for MIMO-OFDM systems is investigated where all transmit antennas share the same sub-carriers to convey pilot symbols. The pilot sequences are endowed with phase-shifting properties, granting the receiver the possibility of extracting the impulse responses for all channels directly from the antennas’ time-domain received signals, without co-channel interference. A linear processing of the time-domain samples is all that is needed to get the channel impulse responses, resulting in an algorithm with very low computational load. The feasibility of the investigated method is substantiated by system simulation using indoor and outdoor broadband wireless channel models.

#### References

- Nee, R. V., Prasad, R., 2000. OFDM for Wireless Multimedia Communications, Artech House. 1st edition.
- Stuber, G. L., Barry, J. R., McLaughlin, S. W., Li, Y., Ingram, M. A., Pratt, T. G., 2004. Broadband MIMOOFDM wireless communications. In Proceedings of the IEEE, vol. 92, no. 2, pp. 271-294.
- Sampath, H., Talwar, S., Tellado, J., Erceg, V., Paulraj, A., 2005. A fourth-generation MIMO-OFDM broadband wireless system design, performance, and field trial results. In IEEE Communications Magazine, pp. 143-149.
- Paulraj, A. J., Gore, D. A., Nabar, R. U., Bolcskei, H., 2004. An overview of MIMO communications - a key to gigabit wireless. In Proceedings of the IEEE, vol. 92, no. 2, pp. 198-218.
- Li, Y. G., Seshadri, N., Ariyavisitakul, S., 1999. Channel estimation for OFDM systems with transmitter diversity in mobile wireless channels. In IEEE Journal on Selected Areas in Communications, vol. 17, no. 3, pp. 461-471.
- Li, Y. G., 2002. Simplified channel estimation for OFDM systems with multiple transmit antennas. In IEEE Transactions on Wireless Communications, vol. 1, pp. 67-75.
- Shin, M., Lee, H., Lee, C., 2004. Enhanced channelestimation technique for MIMO-OFDM systems. In IEEE Transactions on Vehicular Technology, vol. 53, no. 1, pp. 261-265.
- Zhang, H., Li, Y. G., Reid, A., Terry, J., 2005. Channel estimation for MIMO-OFDM in correlated fading channels. In IEEE International Conference on Communications, pp. 2626-2630.
- Zamiri-Jafarian, H., Pasupathy, S., 2007. Robust and improved channel estimation algorithm for MIMOOFDM systems. In IEEE Transactions on Wireless Communications, vol. 6, pp. 2106-2113.
- Barhumi, I., Leus, G., Moonen, M., 2003. Optimal training design for MIMO OFDM systems in mobile wireless channels. In IEEE Transactions on Signal Processing, vol. 51, pp. 1615-1624.
- Minn, H., Al-Dhahir, N., 2004. Optimal training signals for MIMO OFDM channel estimation. In IEEE Global Telecommunications Conference, pp. 219-224.
- Ribeiro, C., Gameiro, A., 2007. Direct time-domain channel impulse response estimation for OFDM-based systems. In IEEE Vehicular Technology Conference.
- Edfors, O., 1996. Low-complexity algorithms in digital receivers, Ph.D. dissertation, Lulea University of Technology, Sweden.
- ETSI TS 101 475 V1.2.2, 2001. Broadband Radio Access Networks (BRAN): HIPERLAN Type 2: Technical specification; Physical layer.

#### Paper Citation

#### in Harvard Style

Ribeiro C. and Gameiro A. (2008). **MIMO-OFDM CHANNEL ESTIMATION - A Pilot Sequence Design for Time-domain Processing** . In *Proceedings of the International Conference on Wireless Information Networks and Systems - Volume 1: WINSYS, (ICETE 2008)* ISBN 978-989-8111-62-3, pages 163-170. DOI: 10.5220/0002026101630170

#### in Bibtex Style

@conference{winsys08,

author={Carlos Ribeiro and Atílio Gameiro},

title={MIMO-OFDM CHANNEL ESTIMATION - A Pilot Sequence Design for Time-domain Processing},

booktitle={Proceedings of the International Conference on Wireless Information Networks and Systems - Volume 1: WINSYS, (ICETE 2008)},

year={2008},

pages={163-170},

publisher={SciTePress},

organization={INSTICC},

doi={10.5220/0002026101630170},

isbn={978-989-8111-62-3},

}

#### in EndNote Style

TY - CONF

JO - Proceedings of the International Conference on Wireless Information Networks and Systems - Volume 1: WINSYS, (ICETE 2008)

TI - MIMO-OFDM CHANNEL ESTIMATION - A Pilot Sequence Design for Time-domain Processing

SN - 978-989-8111-62-3

AU - Ribeiro C.

AU - Gameiro A.

PY - 2008

SP - 163

EP - 170

DO - 10.5220/0002026101630170