Method and Apparatus for quadrature mirror filtering
QMF synthesis (synthesis) filtering method according to an embodiment of the present invention, the position of the samples to be discarded in the first array that contains the modulated QMF subband samples, to write the new sample corresponding to the current timeslot of step; For removing the aliasing between neighboring subbands step of extracting the sample from the first array; Step using a modulo operation to determine the filter coefficients corresponding to the extracted sample; And a step of synthesizing ering aliasing is removed time-domain samples using the extracted samples and the filter coefficients.
A new estimator for a four-element plane array is introduced in order to get acoustic-passive direction estimation of targets.We concern much about the performance of the estimator under a two-target situation.In this paper,the two targets concerned are of the same type of acoustic source.Under different signal to interfere ratios,we propose the change of the precision of the direction estimation as the angle between the two targets changes.Our study was done under the real time Warfield situation,and may help the design of small acoustic-passive direction estimation arrays.