The ability of orthogonal frequency-division multiplexing systems to mitigate frequency-selective channels is impaired by the presence of carrier frequency offsets (CFOs). In this paper, we investigate identifiability issues involving high-resolution techniques that have been proposed for blind CFO estimation based on null subcarriers. We propose new approaches that do not suffer from the lack of identifiability and adopt adaptive algorithms that are computationally feasible. The performance of these techniques in relation to the location of the null subcarriers is also investigated via computer simulations and compared with the modified Cramér-Rao bound.
Bibliographical noteFunding Information:
Manuscript received February 1, 2001; revised July 30, 2001. This work was supported by the NSF Wireless Initiative under Grant 9979443. Part of this work was presented at the Third IEEE Workshop on Signal Processing Advances in Wireless Communications, Taiwan, R.O.C., March 20–23, 2001. X. Ma and G. B. Giannakis are with the Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455 USA (e-mail: email@example.com; firstname.lastname@example.org). C. Tepedelenliog˘lu is with the Department of Electrical Engineering, Arizona State University, Tempe, AZ 85287 USA (e-mail: email@example.com). S. Barbarossa is with the INFOCOM Department, University of Rome “La Sapienza,” 00184 Rome, Italy (e-mail: firstname.lastname@example.org). Publisher Item Identifier S 0733-8716(01)10298-2.
- Modified Cramér-Rao bound
- Multi-carrier transmission
- Orthogonal frequency-division multiplexing (OFDM)