應用小數頻率合成器於GMSK調變

Abstract

在GSM手機通訊標準中，調變信號的方式是GMSK。它是一種連續相位的調變方式，為GFSK的一種。在本論文的研究中，建立了一套使用Simulink的相位調變器行為模型來探討他頻率及spectrum。在晶片中使用一個三角積分調變除小數頻率合成器來實現部分相位調變器的射頻電路。其中相位頻率比較器、電流泵、多模數除頻器及壓控震盪器是用0.35μm混和信號 2P4M CMOS製程的積體電路實現,而三角積分調變器是由 MATLab 通過 pattern generator 來實現。

In GSM communication system, the modulation of the modulated signals are GMSK. It is a kind of modulation way of continuiing phase, a kind of GFSK modulation way. In this work, we set up a complete behavior model of phase modulator in Simulink environment. In this chip, we use a sigma-delta fractional-N frequency synthesizer to implement partial RF circuit of the phase modulator. A phase frequency detector, a charge pump ,a multi-modulus divider and a voltage-controlled oscillator are fabricated with 0.35μm 2P4M CMOS technology and are operated over 1.8 GHz. The sigma-delta modulator is implemented by Simu-link and the pattern generator.