CDMA2000码序列（短码长码WALSH码）.ppt

《CDMA2000码序列（短码长码WALSH码）.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、扩频码速率：1.2288Mcps；扩频码：前向为Walsh码和PN短码，反向为PN长码。扩频码的使用是扩频通信的关键点CDMA扩频码的选择CDMA中使用的扩频码1.3CDMA2000码序列(短码、长码WALSH码)1相关性(a)(b)相关（相关性100％）不相关（0相关）CDMA核心技术+1-1+1-1+1-1+12正交函数正交函数具有0相关性。如果两个二进制序列的异或结果具有相同个数的0和1，那么，这两个序列不相关。000001010101例子:101001011111CDMA核心技术不相关：相关：3

2、Walsh码的定义CDMA中使用的扩频码Walsh码的定义Walsh函数是一种非正弦波的完备正交函数系统，可用哈达玛矩阵H通过递推关系构成。由于它仅有可能的取值是＋1和－1（或0和1），比较适合于用来表达和处理数字信号。Walsh函数具有理想的互相关特性。在Walsh函数中，两两之间的互相关函数为“0”，亦即它们之间是正交的。4WALSHCODES#----------------------------------64-ChipSequence-----------------------------

3、-------------0000000000000000000000000000000000000000000000000000000000000000010101010101010101010101010101010101010101010101010101010101010101200110011001100110011001100110011001100110011001100110011001100113011001100110011001100110011001100110011001100

4、11001100110011001104000011110000111100001111000011110000111100001111000011110000111150101101001011010010110100101101001011010010110100101101001011010600111100001111000011110000111100001111000011110000111100001111007011010010110100101101001011010010110100

5、10110100101101001011010018000000001111111100000000111111110000000011111111000000001111111190101010110101010010101011010101001010101101010100101010110101010100011001111001100001100111100110000110011110011000011001111001100110110011010011001011001101001100

6、10110011010011001011001101001100112000011111111000000001111111100000000111111110000000011111111000013010110101010010101011010101001010101101010100101010110101010010114001111001100001100111100110000110011110011000011001111001100001115011010011001011001101

7、00110010110011010011001011001101001100101101600000000000000001111111111111111000000000000000011111111111111111701010101010101011010101010101010010101010101010110101010101010101800110011001100111100110011001100001100110011001111001100110011001901100110011

8、001101001100110011001011001100110011010011001100110012000001111000011111111000011110000000011110000111111110000111100002101011010010110101010010110100101010110100101101010100101101001012200111100001111001100001111000011001