Design of low complexity parallel polyphase finite impulse response filter using coefficient symmetry

In this correspondence, a mathematical model is developed for the efficient realisation of a generalised M x M polyphase parallel finite impulse response (FIR) filter structure composed of M parallel conventional decimator polyphase filters Primarily, the proposed structure is designed in such a way that the benefit of coefficient symmetry property of linear-phase FIR filters can be availed without using the pre/post circuit blocks. A numerical example is also studied to validate the proposed structure. Furthermore, the delay-elements reduction approach is given to avoid the excessive usage of memory elements and the performance of the proposed structure is evaluated in terms of the number of delay elements (D), adders (A) and multipliers (M). Compared to the traditional structures, our proposed structure is found to be more efficient in terms of M. Moreover, in contrast to the fast FIR algorithms, the proposed structure resolves the issues of additional requirements of the pre/post blocks and the absence of parallel structure with coefficient symmetry for higher prime values of M (i.e. M > 3). The synthesis result reveals that the proposed 37-tap filter (with M = 3 and 12-bit inputs) involves 30% less area-delay-product (ADP) per output and 33.05% less power per output compared to the most recent structure.

Automated summary

This paper develops a mathematical model for the efficient realization of a generalized M x M polyphase parallel finite impulse response filter structure. The proposed structure takes advantage of the coefficient symmetry property of linear-phase FIR filters without the need for pre/post circuit blocks. The reduction of delay elements is also utilized to improve resource usage. The results show that the proposed structure is more efficient compared to traditional structures and resolves issues faced by fast FIR algorithms for higher prime values of M.