MMSE turbo equalisation for real-valued symbols

Autor:	Guido Dietl, Wolfgang Utschick
Rok vydání:	2006
Předmět:	biology Computational complexity theory Iterative method Turbo Wiener filter biology.organism_classification Equaliser symbols.namesake Electronic engineering Turbo code symbols A priori and a posteriori Electrical and Electronic Engineering Algorithm Linear filter Mathematics
Zdroj:	European Transactions on Telecommunications. 17:351-359
ISSN:	1541-8251 1124-318X
Popis:	This paper deals with iterative or turbo receivers where the maximum a posteriori detector has been replaced by a widely linear filter minimising the mean square error, that is the widely linear Wiener Filter (WF). In communication systems where the transmitted symbols can be assumed to be realisations of a non-circular random variable, widely linear processing outperforms the linear one. Besides the non-circularity due to the a priori information fed back in the turbo scheme, we investigate real-valued modulation alphabets which are non-circular even if the a priori information is zero. We derive the widely linear WF for this case and observe that the number of floating point operations involved in its computation, is higher than the one of the linear WF. Nevertheless, they have the same order of computational complexity. Moreover, we reveal the relationship between the proposed widely linear equaliser and interference cancellation based on the available a priori information. Simulation results of a frequency-selective turbo system show that despite of the increased computational complexity, the performance gain of widely linear processing compared to the linear one, is negligible. However, in systems without turbo feedback, the widely linear WF outperforms tremendously the linear one. Copyright © 2006 AEIT
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::ae1596c74412eb32fa651da381c989fa https://doi.org/10.1002/ett.1126 Zobrazit plný text záznamu Plný text