Yamamoto, YutakaAnderson, BrianNagahara, MasaakiKoyanagi, Yoko2015-12-131070-9908http://hdl.handle.net/1885/85848Finite-impulse response (FIR) filters are often preferred to infinite-impulse response (IIR) filters because of their various advantages in respect of stability, phase characteristic, implementation, etc. This letter proposes a new method to approximate an IIR filter by an FIR filter, which directly yields an optimal approximation with respect to the H∞ error norm. We show that this design problem can be reduced to a linear matrix inequality. We will also make a comparison via a numerical example with an existing method, known as the Nehari shuffle.Keywords: Electric network synthesis; IIR filters; Linear control systems; Markov processes; Matrix algebra; Optimization; Poles and zeros; Discrete-time infinite impulse response filters; Finite-impulse response filter approximation; Linear matrix inequality; FIR Finite-impulse response (FIR) filter approximation; H8 optimization; Linear matrix inequality200310.1109/LSP.2003.8156152015-12-12