Low effort MIMO eetector for frequency selective indoor channels

Abstract

A new MIMO detector for frequency selective indoor channels is proposed. The detector is based on a two-stage detection followed by a decision feedback equalizer (DFE). The first detection stage is assured by a linear equalizer subsequently followed by a decision unit. The second step is a reduced search (RS) around the solution acquired by the linear equalization, which will be performed in an efficient way at the different transmitted data streams. The RS will be adjusted depending on the search probability at each level. The DFE is applied in order to remove the effect of the inter symbol interferences (ISI) caused by the channel dispersion as it has been observed in the indoor measurements. The RS method provides a near ML performance while it demands a fixed computational effort which is determined by the number of operations and limited by the hardware resources. Compared to some of the most important MIMO detectors, such as for example V-BLAST and sphere decoder, in simulations as well as in field measurements our approach exhibits a near ML performance in terms of BER while its computational effort always remains distinctly lower.