In the CDMA wireless communications system , multi-access interference and near-far effect exist because spread codes between users are not completely orthogonal along with different users random accessing, regular filter can not overcome these questions.

• 码分多址系统中，不同用户的随机接入，使得用户之间扩频码不完全正交，进而产生了多址干扰(Multi-access interference，MAI)和远近效应(Near-far effect，NFE)等问题，常规的匹配滤波器无法克服这些问题。