IS-54 無線通信標準之基頻傳輸電路設計

Abstract

基頻傳輸電路在數位無線通訊系統中是個重要的部份，它對於數位的基頻 輸出資料的波形加以修正，以使輸出的波形能符合通訊標準的頻譜要求並 減少訊號交相干擾(Inter-symbol Interferences)．在這篇論文中，將以 IS-54 為標準而設計符合標準的基頻傳輸電路．在數位傳輸模式，提出一 個全數位化的架構，將基頻傳送端的兩個通道上的兩個訊號在數位電路中 將之混波在一起，使之輸出到類比及RF部份通道合併為一條，其中頻為３ ８８．８千赫，並且利用內差法以及線性相位慮波器(Linear Phase Filter) 的對稱特性減少硬體數量和提升運算效率．而此一數位傳輸電路 以 0.8um SPDM CMOS 的半導體技術完成設計並送往CIC製造．在類比傳輸 模式中，研究設計出能滿足IS-54 的數值控制震盪器的規格，並使此震盪 器能和數位傳輸電路使用同一時脈源以及同一輸出通道． The baseband transmitter circuit is an important component in the digital wireless communication system. It shapes the output waveform of digital data to satisfy the spectrum requirement of the communication standard and reduce inter-symbol interferences. In this thesis, we designed the baseband transmitter circuit for IS-54 cellular phone. In digital transmission mode, we proposed an all digital architecture to mix the signals in I and Q channels at an IF frequency of 388.8kHz, thus resulting only one signal path leading to the analog and RF section. We used the interpolation techniques and the symmetry properties of linear phase filters to reduce the amount of hardware and enhance the efficiency of computation. The digital transmission mode circuit has been implemented with 0.8um SPDM CMOS technology, and submitted to CIC for fabrication. In analog transmission mode, we investigated the design of a Numerical Controlled Oscillator (NCO) to satisfy the requirement of IS-54 which can use the same clock source and output channel.