Research On Key Technique Of Interleave-Division Multiple-Access

Along with the constant development of wireless communication, limited mobile communication resources have to support the demand of subscribers and service quality which is still increasing explosively. Against such background, Interleave-Division Multiple-Access(IDMA), as a new kind of multiple access technique, has become a popular research topic in wireless communications.This paper first focuses on the research of the fundamental theory and the design structure of IDMA technique, which includes the modules of the transmitter and the receiver, together with the comparison between the IDMA structure and the traditional CDMA system structure. On the other hand, different interleavers turn out to be the only identities to distinguish different users, thus the design method of the interleavers are introduced and classified in the next part of the paper. Then this paper makes a detailed theoretical description and algorithm summary for the iterative multi-user detection technique. At the same time, this paper also analyses the complexity and the performance of the algorithm. In addition, the extension under the condition of multipath channels has been provided.Finally, the paper gives the power allocation strategies in the IDMA technique. The SNR evolution for the iterative process in the chip-by-chip(CBC) multi-user detection algorithm is tracked at first. Then the capacity of an IDMA system is analyzed with ideal FEC coding. On the basis of SNR evolution and capacity calculation, the basic principle of the power allocation algorithm which is depended on the SINR estimation is introduced. However, the linear programming(LP) algorithm based on the SINR estimation is not perfect. Under these circumstances, the power allocation strategy based on SLNR is proposed for the purpose of reducing the complexity of the algorithm. In the end, the performance of the algorithms are compared and analyzed.