Orthogonal frequency-division multiple access (OFDMA) gains increasing attention for broadband, high data rate wireless communications. In this paper, we develop a novel unitary precoded (UP) OFDMA scheme that is particularly appealing for the uplink, because it offers high bandwidth efficiency, and constant modulus transmissions for each user. Theoretical analysis of UP-OFDMA with channel coding shows the performance improvement introduced by unitary precoding. It provides useful guidelines for practical system designs, and also quantifies the performance of UP-OFDMA relative to the single-user bound. Simulations confirm that UP-OFDMA improves performance considerably relative to conventional OFDMA.
Bibliographical noteFunding Information:
Paper approved by C. Tellambura, the Editor for Modulation and Signal Design of the IEEE Communications Society. Manuscript received May 31, 2002; revised May 27, 2003. This work was sponsored by the Communications and Networks Consortium, sponsored 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. This work was also supported by the National Science Foundation under Grant 01-0516. This paper was presented in part at the IEEE Wireless Communications and Networking Conference, New Orleans, LA, March 16-20, 2003.
- Constant modulus
- Multiple access
- Orthogonal frequency-division multiplexing (OFDM)
- Unitary preceding (UP)