The invention provides a method and apparatus for performing complex digital filters. According to one aspect of the invention, a method for performing a complex digital filter is described. The complex digital filter is performed using a set of data samples and a set of complex coefficients. In addition,...http://www.google.com.hk/patents/US6470370?utm_source=gb-gplus-share專利 US6470370 - Method and apparatus for multiplying and accumulating complex numbers in a digital filter
