VLSI implementation of a hardware-optimized lattice reduction algorithm for WiMAX/LTE MIMO detection

This paper presents the first ASIC implementation of an LR algorithm which achieves ML diversity. The VLSI implementation is based on a novel hardware-optimized LLL algorithm that has 70% lower complexity than the traditional complex LLL algorithm. This reduction is achieved by replacing all the computationally intensive CLLL operations (multiplication, division and square root) with low-complexity additions and comparisons. The VLSI implementation uses a pipelined architecture that produces an LR-reduced matrix every 40 cycles, which is a 60% reduction compared to current implementations. The proposed design was synthesized in both 130μm and 65nm CMOS resulting in clock speeds of 332MHz and 833MHz, respectively. The 65nm result is a 4× improvement over the fastest LR implementation to date. The proposed LR implementation is able to sustain a throughput of 2Gbps, thus achieving the high data rates required by future standards such as IEEE 802.16m (WiMAX) and LTE-Advanced.