A new algorithm for realization of FIR filters using multiple constant multiplications

This paper presents a new common subexpression elimination (CSE) algorithm to realize FIR filters based on multiple constant multiplications (MCMs). This algorithm shares the maximum number of partial terms amongst minimal signed digit (MSD)-represented coefficients. It modifies the iterated matching (ITM) algorithm to share more partial terms in MCMs, which yields a significant logic and, consequently, chip area savings. The employment of the proposed algorithm results in efficient realizations of FIR filters with a fewer number of adders compared to the conventional CSE algorithms. Experimental results demonstrate a reduction up to 22% in the complexity of FIR filters over some conventional CSE algorithms. The proposed algorithm also addresses challenges encountered in resource-constrained applications, which require banks of high-order filters, such as in real-time distributed optical fiber sensor.