Design of Flexible Anti-Imaging Filter Based on
Qunqun Zhou, Hongyuan Wang · 2009
A novel algorithm of designing polynomial interpolation filter as anti-imaging filter is presented. The proposed algorithm is based on linear programming techniques and it is easy to implement. Results indicate that the proposed algorithm can achieve maximum attenuation in imaging-band. Furthermore, it is flexible to adjust the frequency response of polynomial interpolator according to different specifications. Sampling rate conversion (SRC) is utilized in many DSP applications where two signals or systems having different sampling rates are to be interconnected. The sampling rate ratio in general can be integer or rational, and is given by: OI I O R FF T T == (1) where FI=1/TI and FO=1/TO are the original input sampling rate and the sampling rate after the conversion, respectively. When the sampling rates are related by a fixed ratio of two small relatively prime integers, the SRC can be performed conveniently with the fixed digital filters in discrete-time model(1). If the ratios are irrational, the fixed digital filters cannot be applied directly. Furthermore, if R is a variable ratio or a ratio of two relatively large prime integers, then the required filter orders become very large. In these cases, an efficient overall implementation based on mimicking the system of hybrid analogue/digital model can be adopted.