The adoption of orthogonal frequency-division multiplexing by wireless local area networks and audio/video broadcasting standards testifies to the importance of recovering block precoded transmissions propagating through frequency-selective finite-impulse response (FIR) channels. Existing block transmission standards invoke bandwidth-consuming error control codes to mitigate channel fades, and training sequences to identify the FIR channels. To enable block-by-block receiver processing, we design redundant precoders with cyclic prefix and superimposed training sequences for optimal channel estimation and guaranteed symbol detectability, regardless of the underlying frequency-selective FIR channels. Numerical results are presented to access the performance of the designed training and precoding schemes.
Bibliographical noteFunding Information:
Paper approved by P. Y. Kam, the Editor for Modulation and Detection for Wireless Systems of the IEEE Communications Society. Manuscript received November 22, 2000; revised October 28, 2001 and June 28, 2002. The work of G. B. Giannakis was supported by the National Science Foundation Wireless Initiative under Grant 9979442. This paper was presented in part at the International Conference on Communications, Helsinki, Finland, June 11–15, 2001.
- Block transmissions
- Channel estimation
- Orthogonal frequency-division multiplexing (OFDM)
- Pilot tones