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EVDO中如何区分控制信道和业务信道
协议上指出，通过前缀中MACindex来区分控制信道和业务信道，前缀是通过64位双正交调制，我想问下如何才能对双正交调制进行解调，以正确解析出macindex呢，望高手解答
我要回答
问题答案
The Forward Channel is a shared medium. Addressing on the shared channel is achieved by a
MAC index that identifies data transmissions from a sector to a particular AT. The preamble of
the Physical packet is covered by a bi-orthogonal sequence, determined by the MAC index of the
desired AT. The AT attempts to decode a Physical packet only if it contains the appropriate
preamble.
深层次的俺不会，不过通俗点讲，可以从以上句子看出：MACindex 包含walsh cover 和调制相位，特定的AT分配特定的mac index。只有当AT获得与AN相对应的前导时，AT才会用分配给自己MACinedx去尝试解码数据包。。。
MAC index that identifies data transmissions from a sector to a particular AT. The preamble of
the Physical packet is covered by a bi-orthogonal sequence, determined by the MAC index of the
desired AT. The AT attempts to decode a Physical packet only if it contains the appropriate
preamble.
深层次的俺不会，不过通俗点讲，可以从以上句子看出：MACindex 包含walsh cover 和调制相位，特定的AT分配特定的mac index。只有当AT获得与AN相对应的前导时，AT才会用分配给自己MACinedx去尝试解码数据包。。。
回答者：bigdolphin 回答时间：2010-08-05 11:45
0
2MacIndex 应该只是被walsh cover扩频，它发送的电平大小应该会比普通的信息码片高，只有这样，才能检测出前缀，确定业务信道的数据包
