Patent ID: 8260836

Claim:
A method for generating a filter coefficient in real time, comprising: looking up a first intermediate value in a first memory in which a converted window function table is stored, based on a current coefficient index; generating a look-up table address, via a look-up table address generation module, the look up table address based on the current coefficient index, a filter order and a current cut-off angular frequency; looking up a second intermediate value in a second memory in which a sine table is stored, based on the look-up table address; and multiplying, via a multiplier, the first intermediate value by the second intermediate value to obtain the filter coefficient; wherein generating the look-up table address comprises: converting, via an index conversion unit, the current coefficient index to obtain a third intermediate value, wherein converting the current coefficient index is realized using the following equation: T n =2 n +1 −N, wherein, T n is the third intermediate value; n is the current coefficient index, n=0, 1, . . . , N−1; and N is the filter order; generating, via a cut-off angular frequency generation unit, the current cut-off angular frequency; and multiplying, via a second multiplier, the third intermediate value by the current cut-off angular frequency to obtain the look-up table address.