Design Of Two-Channel Hybrid Filter Banks Based On Power-Complementary Structure

As the signals in the fields such as radar and telecommunication covers the widerinstantaneous bandwidth, real-time signal processing usually requires high samplingspeed and accuracy of analog-to-digital converter (ADC). Hybrid filter bank is one ofefficient structures which can achieve high-speed, high-resolution parallel samplingADC systems, therefore the designing of hybrid filter banks, satisfying perfectreconstruction condition, has become the main point of the research. This dissertationmainly presents a method for designing a two-channel hybrid filter banks by solving aminimax problem and a one-dimensional optimization problem derived from the nearperfect reconstruction conditions.The design starts with a power-complementary structure of3-order analoganalysis filters with a free parameter, which is derived from given specificationrestraints. With this parameter fixed, digital synthesis filters can be designed inminimax sense by using second order cone programming algorithm, and thecorresponding maximum reconstruction error is obtained simultaneously. Assumingthat the free parameter varies in a discretized range, the maximum reconstruction erroris further regarded as an objective function and minimized by using golden-sectionsearch and parabolic interpolation algorithm. Then the designing of two-channel hybridfilter banks can be accomplished using the optimal parameter. A design example showsthat this method yields much reduced aliasing and amplitude distortion in comparisonwith conventional methods. Furthermore, analog deviation is considered in thisdissertation. An input-dependent model based on Parseval’s relation for discrete-timeperiodic signals is used to estimate the deviation. With the calibrated analog analysisfilters, the matched digital synthesis filters can be designed using second order coneprogramming algorithm. Simulation results show that this estimation methodefficiently reduces the influence of analog deviation for hybrid filter bank ADCsystem.