Blind equalization by direct examination of the input sequences
1995 (English)In: IEEE Transactions on Communications, ISSN 00906778 (ISSN), Vol. 43, no 7, 2213-2222 p.Article in journal (Refereed) Published
This paper presents a novel approach to blind equalization (deconvolution), which is based on direct examination of possible input sequences. In contrast to many other approaches, it does not rely on a model of the approximative inverse of the channel dynamics. To start with, the blind equalization identifiability problem for a noise-free finite impulse response channel model is investigated. A necessary condition for the input, which is algorithm independent, for blind deconvolution is derived. This condition is expressed in an information measure of the input sequence. A sufficient condition for identifiability is also inferred, which imposes a constraint on the true channel dynamics. The analysis motivates a recursive algorithm where all permissible input sequences are examined. The exact solution is guaranteed to be found as soon as it is possible. An upper bound on the computational complexity of the algorithm is given. This algorithm is then generalized to cope with time-varying infinite impulse response channel models with additive noise. The estimated sequence is an arbitrary good approximation of the maximum a posteriori estimate. The proposed method is evaluated on a Rayleigh fading communication channel. The simulation results indicate fast convergence properties and good tracking abilities.
Place, publisher, year, edition, pages
1995. Vol. 43, no 7, 2213-2222 p.
Algorithms, Computational complexity, Constraint theory, Fading (radio), Mathematical models, Statistical methods, Blind equalization, Input sequences, Maximum a posteriori estimate, Rayleigh fading communication channel, Signal processing
IdentifiersURN: urn:nbn:se:kth:diva-55421DOI: 10.1109/26.392964OAI: oai:DiVA.org:kth-55421DiVA: diva2:471608
Correspondence Address: Gustafsson, Fredrik; Linkoping Univ, Linkoping, Sweden NR 201408052012-01-022012-01-022013-09-05Bibliographically approved