Low complexity channel estimation for low-mobility LTE using 4×4 MIMO

Multiple-input multiple-output (MIMO) is a mandatory feature of the Third Generation Partnership Project (3GPP) Long Term Evolution. This work investigates the performance of a low complexity channel estimator for LTE terminals with an emphasis on the 4 × 4 multiple antenna scheme. The presented work extends a promising low-complexity 2 × 2 MIMO channel estimator to the 4 × 4 MIMO case and evaluates its performance at different terminal speeds. The evaluation is done in terms of simulated error performance for coded LTE. We show that the presented channel estimator can be used without a significant performance loss up to about 15-20 km/h, where the approximations done to achieve low complexity start to have a significant impact on the performance.