【正文】 .......................................................................2 擴頻通信原理.................................................................................................................................3 擴頻通信基本概念..............................................................................................................3 擴頻通信的基本原理..........................................................................................................3 擴頻通信的理論基礎(chǔ)..........................................................................................................4 CDMA 碼序列 ................................................................................................................................5 Walsh 碼 ...............................................................................................................................6 PN 短碼 ................................................................................................................................7 PN 長碼 ................................................................................................................................9 三種擴頻碼的比較..............................................................................................................9 CDMA 關(guān)鍵技術(shù) ..........................................................................................................................10 功率控制............................................................................................................................10 軟切換................................................................................................................................14 RAKE 接收機工作原理 .....................................................................................................20 CDMA 呼吸效應(yīng) ...............................................................................................................21第 2 章 CDMA 的信道 ..........................................................................................................24 IS95 信道 ......................................................................................................................................24 反向 CDMA 信道 .............................................................................................................24 前向 CDMA 信道 .............................................................................................................26 CDMA2022 1x 的新特性 .............................................................................................................29 CDMA2022 1x 信道 ..........................................................................................................30第 3 章 CDMA 空中信令流程 ..............................................................................................33 與信令流程有關(guān)的幾個概念.......................................................................................................33 IMSI ....................................................................................................................................33 ESN.....................................................................................................................................34 登記....................................................................................................................................34 導(dǎo)頻信號集........................................................................................................................34 移動臺狀態(tài)變遷流程...................................................................................................................34 CDMA 基本信令流程 ..................................................................................................................39 語音業(yè)務(wù)起呼....................................................................................................................39 語音業(yè)務(wù)被呼....................................................................................................................402 / 85 位置登記的流程................................................................................................................41 短消息的流程....................................................................................................................42 切換流程............................................................................................................................44 語音業(yè)務(wù)釋放....................................................................................................................47 數(shù)據(jù)業(yè)務(wù)起呼....................................................................................................................48第 4 章 CDMA 空口技術(shù)規(guī)范、協(xié)議 ..................................................................................50 協(xié)議架構(gòu).......................................................................................................................................50 空中接口層次結(jié)構(gòu).......................................................................................................................51 物理層描述........................................................................................................................51 MAC 層描述 ......................................................................................................................52 LAC 層描述........................................................................................................................52 層 3 描述............................................................................................................................53 A 接口協(xié)議層次 ............................................................................................................................53 A 接口協(xié)議層次結(jié)構(gòu) .........................................................................................................53 內(nèi)部接口層次結(jié)構(gòu)............................................................................................................54第 5 章 CDMA 2022 1X EVDO 原理 .....................................................