Channel gain mismatch and time delay calibration for modulated wideband converter-based compressive sampling

The modulated wideband converter (MWC) is a recently proposed compressive sampling system for acquiring sparse multiband signals. For the MWC with digital sub-channel separation block, channel gain mismatch and time delay will lead to a potential performance loss in reconstruction. These gains and delays are represented as an unknown multiplicative diagonal matrix here. The authors formulate the estimation problem as a convex optimisation problem, which can be efficiently solved by utilising least squares estimation. Then the calibrated system model is obtained and the estimates of the gains and time delays of physical channels from the estimate of this matrix are calculated. Numerical simulations verify the effectiveness of the proposed approach.