Direct Sequence CDMA Systems
Zhao Zheng,Yin Qinye,Wu Xiaojun,Feng Aigang
(School of Electronics and Information Engineering,Xi'an Jiaotong Univercity 710049,China)
Abstract:A reduced dimension multiuser detection based on wavelet transformation is proposed. With wavelet transformation, at the receiver, the user signal dimension is reduced and at the same time the signals of different users are separated into several groups. And then multiuser detection is applied to each group. Multiuser detector has the character that its performance increases with the decrease of the number of users. The separation of users implies that the number of input users of multiuser detection decreases. That makes up the performance decrease caused by the dimensional reduction and reduces the computation load of some multiuser detectors. Simulation results confirm that compared with full dimension multiuser detection, the performance decreases under the condition of high input SNR, but not decreases under the condition of low input SNR and large number of users.
Keywords:multiuser detector;wavelet transform;reduced dimension;design of spreading code