This letter proposes a novel block differentially encoded orthogonal frequency-division multiplexing for multicarrier transmissions over frequency-selective fading channels. Choosing appropriate system parameters, we divide the set of correlated subchannels into subsets of independent subchannels. Within each subset, differential unitary space-time modulation is performed by treating each subchannel as a transmit antenna. In addition to low complexity, the proposed system enjoys maximum niultipath diversity and high coding advantages. Analytic evaluation and corroborating simulations reveal its performance merits. Differential encoding, diversity methods, orthogonal frequency-division multiplexing (OFDM).
Bibliographical noteFunding Information:
Manuscript received July 9, 2001; revised October 17, 2001; accepted March 10, 2003. The editor coordinating the review of this paper and approving it for publication is R. A. Valenzuela. This work was supported by the NSF Wireless Initiative Grant 9979442, and by the ARO Grant DAAG55-98-1-0336, and in part by the ARL/CTA Grant. This paper was presented at the 39th Allerton Conference, University of Illinois at Urbana–Champaign, Monticello, IL, October 3–5, 2001.