Design of Non-uniform Filter Banks for DVB-RCS2 Reverse Link

Abstract

This paper introduces a multirate filter for the DVB-RCS2 reverse link in the receive end. To effectively process the received wideband signals, non-uniform filter banks with high stopband attenuation and narrow transition bandwidth are designed. We introduce a method for designing the prototype filter of the filter bank whose optimization objective is to minimize the stop-band error. The complex nonlinear function is transformed into a linear optimization objective, and the optimal solution is gradually approached by a linear iterative method. We can obtain the prototype filter with fast iterative convergence speed and small iterative error. This method shows good application potential in complex channel numbers environments assuming that the filter bank channel number is an even multiple times of the prototype filter order. By merging the adjacent channels of the cosine modulated filter banks(CMFB) as sub-bands and setting the transition band according to the requirements of spectral efficiency, a non-uniform filter bank(NUFB) meets the DVB-RCS2 reverse link stopband attenuation requirements is designed. It achieves simultaneous demodulation of multiple carriers arbitrarily located at different center frequencies on satellite payloads. We demonstrate the superiority of the method and advantages of the filter bank when it's applied to the receive end for DVB-RCS2 reverse link through designing filter banks with different channel numbers.