Variable bandwidth FIR filters with fixed length based on least square fitting

This paper mainly proposes a least square fitting method to obtain variable bandwidth FIR filters with fixed length. The proposed method fits every corresponding tap of fixed filters with the same length and sampling rate but different bandwidth. The bandwidth is the variable of the fitting polynomials in this method, which makes it easier to get filters with needed bandwidth online than traditional methods. The new filter has not only better timeliness property but also simpler design process. The simulation results show that the performance of the variable filters is as good as that of the fixed filters.