NEW APPROACH FOR PLL LOOP FILTER DESIGN USING LINEAR PROGRAMMING AND SEMI-DEFINITE PROGRAMMING

Abstract

Achieving optimal design of phase-locked loop (PLL) is a major challenge in WiMax technology in order to improve system behaviour (overshoot & settling time). A new loop filter design method for PLLs is introduced taking into consideration various mobile WiMax design objectives namely: small settling time, minimum overshoot and working mobile WiMax frequency range. Filter design based on optimizing conflicting objectives is accomplished via linear programming and Semi-Definite Programming (SDP) in conjunction with appropriate adjustment of certain design parameters. Digital Finite Impulse Response (FIR) filter is designed using linear programming and SDP shows better results than other comparable designs. The filter design based on SDP outperformed the design based on Linear Programming.