Complexity Study of Lattice Reduction for MIMO Detection

This paper analyses lattice reduction for MIMO decoding and investigates how different parameters affect the complexity. Lattice reduction is a promising technique and a common approach to implementing it is to use the LLL algorithm. In this paper we show how the complexity of the LLL algorithm depends on such parameters as the number of antennas, SNR, channel correlation and channel matrix column sorting. Both real- and complex-valued versions are considered and complexity-performance trade-offs are also studied.