An improved polynomial-time algorithm for designing digital filters with power-of-two coefficients

An improved algorithm is presented for designing digital filters with coefficients expressed as sums of signed power-of-two (SPT) terms. Our algorithm allocates SPT terms based on minimizing the filter´s approximating error using two l^∞ norms, one in the time domain and one in the frequency domain. For any specified filter gain, the time complexity of the algorithm is a second-order polynomial in the filter order. Examples show that our improved algorithm is capable of designing filters with better characteristics while using fewer SPT terms