MIMO Equalization for Multi-Gbit/s Communication Under Channel Variability

Multiple-input multiple-output (MIMO) equalization at the transmitter and/or receiver has been shown to enable multi-Gbit/s communication over lowcost electrical interconnects. Because of the high operating frequencies, however, the interconnects become susceptible to manufacturing tolerances and the equalization filters must be adjusted to the specific channel realization to achieve optimal performance. To reduce the implementation complexity, we propose a MIMO transceiver scheme where (part of) the equalization filters depend on the channel statistics rather than the actual channel. More specifically, we consider fixed MIMO linear pre-equalization, which avoids the need for a feedback channel with the channel state information, combined with MIMO decision feedback equalization (DFE) at the receiver. Depending on the level of channel variability, the DFE filters can be either fixed or adjustable.