Embodiments are disclosed for improving precoder-matrix computations in a MIMO base station. Particularly, various embodiments implement methods for interpolating pilot signal results from multiple calibration transmissions. A subchannel of a resource block is selected as an anchor subchannel and the channel matrices for each subchannel are then determined using weights associated with each subchannel that are determined from the subchannel's distance away from the anchor subchannel. Selecting variable subchannels allows the accuracy of the channels matrices for the subchannels to be tailored where more accuracy is desired.