R.K. Martin, K. Vanbleu, M. Ding, G. Ysebaert, M. Milosevic, B.L. Evans, M. Moonen, and C.R. Johnson, Jr.
Submitted to IEEE Transactions on Signal Processing on December 14, 2003.
Equalization is crucial in mitigating inter-carrier and inter-symbol interference. To ease equalization in a multicarrier system, a cyclic prefix (CP) is typically inserted between successive symbols. When the channel order exceeds the CP length, equalization can be accomplished via a time-domain equalizer (TEQ), which is a finite impulse response (FIR) filter. The TEQ is placed in cascade with the channel to produce an effective shortened impulse response. Alternatively, a bank of equalizers can be used to remove the interference tone-by-tone. This paper presents a unified treatment of optimal equalizer designs for multicarrier receivers. It is shown that almost all equalizer designs share a common mathematical framework that is based on the maximization of a product of generalized Rayleigh quotients. This framework is used to give an overview of existing designs, to apply a unified notation, and to present various common strategies to obtain a solution. Moreover, the unification emphasizes the differences between the methods, which enables a comparison of their advantages and disadvantages. In addition, an extensive literature survey is given.