Coping with time-selective fading channels is challenging but also rewarding, especially with multiantenna systems, where joint space-Doppler diversity and coding gains can be collected to enhance performance of wireless mobile links. These gains have not been quantified, and space-time coded systems maximizing joint space-Doppler benefits have not been designed. Based on a parsimonious basis expansion model for the underlying time-selective (and possibly correlated) channels, we quantify these gains in closed form. Furthermore, we develop space-time-Doppler coded systems that guarantee the maximum possible space-Doppler diversity, along with the largest coding gains within all linearly coded systems. Our three novel designs exploit knowledge of the maximum Doppler spread, and each offers a uniquely desirable tradeoff, including high spectral efficiency, low decoding complexity, and high performance. Our analytical results are confirmed by simulations and reveal the relative of merits of our three designs in comparison with an existing approach.
Bibliographical noteFunding Information:
Manuscript received October 23, 2003; revised July 8, 2004. This work was prepared through collaborative participation in the Communications and Networks Consortium and supported by the U. S. Army Research Laboratory under the Collaborative Technology Alliance Program, Cooperative Agreement DAAD19-01-2-0011. The U. S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon. Part of the work in this paper was presented at the International Conference on Acoustics, Speech, and Signal Processing, Orlando, FL, May 13–17, 2002. The associate editor coordinating the review of this manuscript and approving it for publication was Prof. Zhi Ding.
- Basis expansion channel model
- Phase sweeping
- Space-time coding
- Time-varying channel