A wind turbine control unit comprising a control module configured to control an actuator system by outputting a first control signal, wherein the first control signal includes a current control sample value and a predicted control trajectory; the control unit further comprising an upsampling module configured to receive the first control signal from the control module, and to output a second control signal for controlling the actuator system, the second control signal having a higher frequency that the first control signal. The upsampling module calculates the second control signal in dependence on the current control sample value and the predicted control trajectory. The embodiments provide a more accurately reproduced control signal at a higher frequency that is suitable for onward processing which does not suffer from the problems of aliasing and delay that exist with conventional upsampling techniques.