Study On Cross-layer Design Based On MIMO Wireless Communication System

With the rapid growth in the number of mobile phone users in the whole world, and the increase in high rate and wideband wireless business volume, the contradiction between wireless communication service requirements and limited wireless resources becomes increasingly conspicuous. At present, in wireless communication system, the first problem to be solved is that high-capacity and high-rate wireless data flow transmitted in limited frequency spectrum resources, requires the key technology with higher spectral efficiency, in order to satisfy more needs from men. Multiple-input multiple-output (MIMO) takes full advantage of space resources, and becomes one of the key technologies for next generation wireless communication system. And MIMO achieves multiple-transmit multiple-receive using muti-antennas and results in that channel capcity and spectral efficiency are doubled, while not increasing frequency spectrum resources and antenna transmit power.Although achieving a great success in the wired networks, traditional layered design with independent protocol layers doesn't adapt to variable wireless networks, and results in not making effective use of limited spectral efficiency. However, cross-layer design method proposed in recent years, utilizes the relativity among network's protocol layers, and can adapt to dynamic variation of wireless network, obtaining adaptive optimal configure and rational resources allocation. Now, cross-layer design becomes a hot research topic for wireless communication system. In this dissertation, we study on the cross-layer design theory for MIMO wireless communication system, and cross-layer design schemes based on single-user system, multi-user system and cooperative transmission system are proposed.In this dissertation, firstly, we introduce the technology of MIMO and cross-layer design, the background and meaning of this dissertation, and analyze research situation for MIMO, cross-layer design and some related technologies. Secondly, for the key technologies of current reseach, we will open the floor for discussion from the follwing four aspects:1. In single-user multi-antenna system, a closed-loop multi-antenna cross-layer design scheme CL-MRC is proposed, analyze the impact of delayed feedback on the system performance, and derive the closed-form for the spectral efficiency and outage of probability;2. Due to complicated for CL-MRC, a simple cross-layer design scheme with only one receive antenna for single-user system, named CL-MBF is proposed, and analyse and compare the performances between CL-MRC and CL-MBF;3. Bringing two cross-layer schemes of single-user system into muti-user system, utilizing "greedy schedule" strategy, and two cross-layer schemes MCL-MRC and MCL-MBF are formed based on multi-user system with multi-antenna diversity and multi-user diversity, and then analyze and compare the performances between MCL-MRC and MCL-MBF under outdated feedback;4. In virtual MIMO cooperative system, CCL cross-layer scheme and Selective-CCL cross-layer scheme are proposed, and discuss the system performances for I.I.D and Non-I.I.D separately.For the new protocols and algorithms mentioned above, the simulation experiments are carried out based on MatLab, the experimental results confirm compared to original system, the system performance of CL-MRC, CL-MBF, MCL-MRC, MCL-MBF, CCL and Selective-CCL cross-layer scheme are all improved.In conclusion, research findings in the dissertation are of profound theoretical significance and practical application purpose for the study on the performance of wireless MIMO communication.