A modified coherent compensation method for subband fusion

Coherent compensation is a significant problem to multiband radar signal fusion. At present, the dominant root-MUSIC and linear least squares(LLS) based ways use band extrapolation (BWE) to generate the whole band signals, and then apply optimization to get the incoherent phases(ICPs). The precision of these methods are limited by the BWE error and the non-corresponding poles. Furthermore, the high dimensional optimization imposes a heavy burden on the computer. In order to improve the performance of the coherent compensation, the incoherent factors between sub-band signals are analyzed first, then in order to correct the non-corresponding poles, a poles correction process which makes use of minimum entropy principle is presented. Based on these, this paper provides an efficient way to estimate the ICPs of sub-band radar signals. Applications to simulated data verify that the proposed method can get better ICPs estimation results.