Loop-reduction LLL algorithm and architecture for lattice-reduction-aided MIMO detection

We propose a loop-reduction LLL (LR-LLL) algorithm for lattice-reduction-aided (LRA) multi-input multioutput (MIMO) detection. The LLL algorithm is an iterative algorithm that contains many check and process operations; however, the traditional LLL algorithm itself possesses a lot of redundant check operations. To solve this problem, we propose a look-ahead check technique that not only reduces the complexity of the LLL algorithm but also produces the lattice-reduced matrix which obeys the original LLL criterion. Simulation results show that the proposed LR-LLL algorithm reduces the average number of loops or computation complexity. Besides, it also shortens the latency of clock cycles about 19.4%, 29.1%, and 46.1% for 4 × 4, 8 × 8, and 12 × 12 MIMO systems, respectively.