【正文】 業(yè)務(wù)信道 ?碼符號重復(fù)為塊交織器提供一恒定速率的數(shù)據(jù)輸入 。 Pilot Channel (All 0) Mcps I PN Q PN Walsh Function 0 導(dǎo)頻信道的捕獲 ? 移動(dòng)臺(tái)自身開始產(chǎn)生 I和 Q PN短碼序列，并用其與接收到的復(fù)合信號中的每一種可能偏置的信號進(jìn)行相關(guān)運(yùn)算 ? 在 15秒內(nèi) (典型值 2到 4秒 )， 所有可能的偏置 (32,768)均檢查一遍 ? 移動(dòng)臺(tái)記住具有最佳相關(guān)性（ Ec/I0最佳）的信號的偏置 ? 移動(dòng)臺(tái)開始用沃氏碼 32解調(diào)信號 00...01 00...01 00...01 00...01 00...01 00...01 00...01 導(dǎo)頻信道 (Walsh Code 0) 前向同步信道 ? 用于提供系統(tǒng)基本參數(shù) ? 系統(tǒng)捕獲階段采用 ? 比特率為 1200bps ? 移動(dòng)臺(tái)在每次呼叫結(jié)束時(shí)重新與系統(tǒng)同步 (Acquired Pilot) 同步信道 同步信道的生成 ? 沃氏碼 32用于擴(kuò)展每個(gè)調(diào)制符，因而導(dǎo)致速率增加256倍；輸出的 0和 1叫比特片（或碼片 chip） ?一個(gè)同步信道幀中有 32,768個(gè)碼片 (每初始比特對應(yīng) 1024個(gè)碼片 ) 1200 bps Walsh Function 32 Mcps I PN Q PN Convolutional Encoder and Repetition Block Interleaver R = 1/2 Modulation Symbols 4800 sps 4800 sps Bits Chips 前向?qū)ず粜诺? ? 單個(gè) CDMA載頻最多可支持七個(gè)尋呼信道 ? 信道 1(沃氏函數(shù) 1)為基本尋呼信道 ? 其它附加的尋呼信道用沃氏函數(shù) 2到 7 ? 不用的尋呼信道可用于前向業(yè)務(wù)信道 ? 支持兩種速率： 9600和 4800bps 尋呼信道 基站用尋呼信道 發(fā)送系統(tǒng)開銷信息 和與特定移動(dòng)臺(tái)相關(guān)的消息 . 尋呼信道的生成 ? 沃氏碼 1(或 2, ... 或 7)用于擴(kuò)頻， 因此其速率增加 64倍，為 Mcps ?就是說，每尋呼信道幀 24,576個(gè) chips，或者說 9600 [4800]bps時(shí)，每個(gè)初始比特對應(yīng) 128 [256]個(gè)比特片。 ? 一個(gè)零偏置短碼序列與它自身的任何非零偏置的短碼序列正交。 m序列發(fā)生器由：移位寄存器、反饋抽頭、模 2加法器組成。 ? m序列是“最長線性反饋移位寄存器序列”的簡稱。 Walsh碼的定義 : Walsh碼的定義 沃爾什碼 （ w alsh code ） W a l s h 函數(shù) , 正交 , 用于 C D MA 系統(tǒng)前向擴(kuò)頻 011011001010000010000 ?? H n H nH 2n = ___ H n H nWALSH CODES 64Chip Sequence 0 0000000000000000000000000000000000000000000000000000000000000000 1 0101010101010101010101010101010101010101010101010101010101010101 2 0011001100110011001100110011001100110011001100110011001100110011 3 0110011001100110011001100110011001100110011001100110011001100110 4 0000111100001111000011110000111100001111000011110000111100001111 5 0101101001011010010110100101101001011010010110100101101001011010 6 0011110000111100001111000011110000111100001111000011110000111100 7 0110100101101001011010010110100101101001011010010110100101101001 8 0000000011111111000000001111111100000000111111110000000011111111 9 0101010110101010010101011010101001010101101010100101010110101010 10 0011001111001100001100111100110000110011110011000011001111001100 11 0110011010011001011001101001100101100110100110010110011010011001 12 0000111111110000000011111111000000001111111100000000111111110000 13 0101101010100101010110101010010101011010101001010101101010100101 14 0011110011000011001111001100001100111100110000110011110011000011 15 0110100110010110011010011001011001101001100101100110100110010110 16 0000000000000000111111111111111100000000000000001111111111111111 17 0101010101010101101010101010101001010101010101011010101010101010 18 0011001100110011110011001100110000110011001100111100110011001100 19 0110011001100110100110011001100101100110011001101001100110011001 20 0000111100001111111100001111000000001111000011111111000011110000 21 0101101001011010101001011010010101011010010110101010010110100101 22 0011110000111100110000111100001100111100001111001100001111000011 23 0110100101101001100101101001011001101001011010011001011010010110 24 0000000011111111111111110000000000000000111111111111111100000000 25 0101010110101010101010100101010101010101101010101010101001010101 26 0011001111001100110011000011001100110011110011001100110000110011 27 0110011010011001100110010110011001100110100110011001100101100110 28 0000111111110000111100000000111100001111111100001111000000001111 29 0101101010100101101001010101101001011010101001011010010101011010 30 0011110011000011110000110011110000111100110000111100001100111100 31 0110100110010110100101100110100101101001100101101001011001101001 32 0000000000000000000000000000000011111111111111111111111111111111 33 0101010101010101010101010101010110101010101010101010101010101010 34 0011001100110011001100110011001111001100110011001100110011001100 35 0110011001100110011001100110011010011001100110011001100110011001 36 0000111100001111000011110000111111110000111100001111000011110000 37 0101101001011010010110100101101010100101101001011010010110100101 38 0011110000111100001111000011110011000011110000111100001111000011 39 0110100101101001011010010110100110010110100101101001011010010110 40 0000000011111111000000001111111111111111000000001111111100000000 41 0101010110101010010101011010101010101010010101011010101001010101 42 0011001111001100001100111100110011001100001100111100110000110011 43 0110011010011001011001101001100110011001011001101001100101100110 44 0000111111110000000011111111000011110000000011111111000000001111 45 0101101010100101010110101010010110100101010110101010010101011010 46 0011110011000011001111001100001111000011001111001100001100111100 47 0110100110010110011010011001011010010110011010011001011001101001 48 0000000000000000111111111111111111111111111111110000000000000000 49 0101010101010101101010101010101010101010101010100101010101010101 50 0011001100110011110011001100110011001100110011000011001100110011 51 0110011001100110100110011001100110011001100110010110011001100110 52 0000111100001111111100001111000011110000111100000000111100001111 53 0101101001011010101001011010010110100101101001010101101001011010 54 0011110000111100110000111100001111000011110000110011110000111100 55 0110100101101001100101101001011010010110100101100110100101101001 56 0000000011111111111111110000000011111111000000000000000011111111 57 0101010110101010101010100101010110101010010101010101010110101010 58 0011001111001100110011000011001111001100001100110011001111001100 59 0110011010011001100110010110011010011001011001100110011010011001 60 0000111111110000111100000000111111110000000011110000111111110000 61 0101101010100101101001010101101010100101010110100101101010100101 62 00