High Speed Look-Ahead LMS Detector for MIMO Systems

Adaptive MIMO detection is used when knowledge of the channel is unavailable. We propose an efficient look-ahead LMS algorithm for MIMO systems which has no noticeable performance loss compared to the standard LMS procedure. In particular, the additional logic introduced into the feedback path can be retimed to reduce the critical path delay. We illustrate this by implementing both the retimed look-ahead LMS and standard LMS on a Xilinx Virtex 4 FPGA. Our synthesis results show that the new design can operate at 173 MHz, compared to 135 MHz for standard LMS.