华为CDMA2000在接收端实现信号恢复

在接收端的信号恢复 1 0 0 1 1 +1 -1 接收数据 1001 0110 0110 1001 1001 0110 0110 0110 0110 0110 1111 0000 0000 1111 1111 相关扩频序列 ? ? ? ? ? 接收数据 1001 0110 0110 1001 1001 0101 0101 0101 0101 0101 1100 0011 0011 1100 1100 不相关扩频序列 CDMA 核心技术 The receiver despreads the chips by using the same Walsh code used in the transmitter. Notice that under no-noise conditions, the symbols or digits are completely recovered without any error. In reality, the channel is not noise-free, but cdma system employ Forward Error Correction techniques to combat the effects of noise and enhance the performance of the system. When the wrong Walsh sequence is used for despreading, the resulting correlation yields an average of zero. This is a clear demonstration of the advantage of the orthogonality property of the Walsh codes. Whether the wrong code is mistakenly used by the target user or other users attempting to decode the received signal, the resulting correlation is always zero because of the orthogonality property of Walsh sequences.