Tongxin xuebao (Sep 2017)
DFT-SV-OFDM based adaptive multi-rate DFT scrambling vector code division multiple access
Abstract
Multipath interference would degrade the performance of multi-rate systems based on OFDM and CDMA,which spectrum efficiency was also lower relatively.To improve the performance and spectrum efficiency,a novel adaptive multi-rate DFT scrambling vector multi-carrier CDMA (AMR-DFT-VMC-CDMA) was proposed based on the theory of matrix permutation and r-cyclical matrix decomposition characteristics.Meanwhile,by theoretical analysis,the parameters of the system could be adaptively adjusted to ensure frame length long enough to break the restriction between channel bit error rate and data frame length on a certain channel utilization condition.The simulation results show that compared with the traditional multi-rate,multi-subcarrier and spreading system,the new system could achieve multi-rate and multi-user information transmission flexibly with better performance and better spectrum efficiency in fading channels.Moreover,it can satisfy the requirement of frame length under certain channel utilization by adjusting the parameters.
