Study of multirate systems and filter banks using GNU Radio

Multirate digital signal processing finds application in various fields like speech processing, image processing and compression. A proper study of this subject is fundamental to incorporating an efficient design of these systems. A good theoretical explanation in this area is readily available at large numbers. But it is quite unfortunate that the present education system does not emphasize a proper visualization of the theoretical concepts. The significance of GNU Radio, which provides various signal processing blocks, is worth noticing since it can be used by a learner to design a flow graph and analyze its response. In this paper, we have implemented the perfect reconstruction filter using the concept of Quadrature mirror filter (QMF) bank in GNU Radio. Some basic concepts like aliasing and filter design have also been analyzed using GNU Radio. We appreciate the role played by GNU Radio since it is an easy-to-use software and also provides an excellant platform in analyzing a system.