Frequency-Response Masking Approach for Design of Intermediate Frequency Filters in CDMA and Wideband GSM Modules

Linear phase filter shares the superiority of high stability and easiness for realization. However, computational complexity increases as the transition band turns sharp. Frequency-response masking (FRM) technique solves this problem by producing sharp filters with low complexity. This is an efficient way to design intermediate frequency filters. In each filter module, some improvements are made for FRM to reduce the computational complexity in further extent. Some examples are applied to illustrate our approach´s superiority