B-spline channel estimation for multiuser LTE uplink

This paper addresses the channel estimation in receivers of multicarrier communication signals, particularly in multiuser scenarios of the LTE uplink. B-splines are proposed for estimation of the time-frequency channel response. Cubic B-splines are considered as the appropriate basis functions allowing a trade-off between the estimation accuracy and complexity. We investigate the iterative channel estimation that, in addition to the pilot symbols, utilizes tentative data estimates for improving the channel estimation performance. B-splines with a model-based regularization developed from a constraint to the channel delays are shown to achieve a performance similar to that of the discrete prolate spheroidal sequences (optimal for the delay constraint), whereas possessing significantly lower complexity.