Special Issue Paper
Joint Tx/iterative Rx FDE for broadband direct-sequence code division multiple access
Article first published online: 27 DEC 2010
Copyright © 2010 John Wiley & Sons, Ltd.
Wireless Communications and Mobile Computing
Special Issue: Innovative Communications for a Better Future
Volume 10, Issue 12, pages 1537–1547, December 2010
How to Cite
Takeda, K. and Adachi, F. (2010), Joint Tx/iterative Rx FDE for broadband direct-sequence code division multiple access. Wirel. Commun. Mob. Comput., 10: 1537–1547. doi: 10.1002/wcm.1063
- Issue published online: 27 DEC 2010
- Article first published online: 27 DEC 2010
- direct-sequence code division multiple access (DS-CDMA);
- frequency-domain equalization (FDE);
- iterative interference cancellation;
- imperfect channel estimation
Direct-sequence code division multiple access (DS-CDMA) is a promising uplink access technology for broadband cellular mobile communication systems. In this paper, we propose a joint transmit (Tx)/iterative receive (Rx) frequency-domain equalization (FDE) for DS-CDMA. In the proposed scheme, simple one-tap FDE at the transmitter and iterative one-tap FDE at the receiver are jointly performed using the common knowledge of channel state information (CSI). Before transmitting the signal, the transmitter predicts the degree of residual inter-chip interference (ICI) power after the iterations of Rx FDE to determine the Tx FDE weight while the receiver performs the iterative Rx FDE. In practice, it is almost impossible to share the perfect knowledge of CSI. In this paper, a Gaussian approximation of channel estimation (CE) errors is introduced. We theoretically derive a set of Tx and iterative Rx FDE weights based on the minimum mean square error (MMSE) criterion in the presence of the CE error. We show by computer simulation that the proposed scheme provides better bit error rate (BER) performance than the conventional scheme which uses iterative Rx FDE only (i.e., without Tx FDE) even in the presence of CE error. Copyright © 2010 John Wiley & Sons, Ltd.