A new adaptive blind equaliser structure with robustness to loss of channel disparity

We address the problem of blind fractionally spaced channel (FSC) identification/equalisation when channel disparity is lost. With an extension of the eigen-vector based algorith (EVAM), we show that it is possible to identify the uncommon part of an FSC. The new blind decision feedback equaliser (DFE) structure therefore first equalises the uncommon part of the channels with a fractionally spaced feedforward equaliser, and then uses a baud spaced DFE to equalise the common part of the channels. We also demonstrate that this new equaliser structure is appropriate for difficult channels, with non-minimum phase zeros close to the unit circle. Simulation studies are included to support the work.