Researches On Lte System Resource Scheduling Algorithm Simulation And Its Implementation On Software Radio Platform

As the transition from the third generation (3G) to fourth-generation (4G) wireless communication system, long term evolution (LTE) adopts orthogonal-frequency division-multiplexing (OFDM) and multiple-input multiple-output (MIMO) as the key technologies. Because of its high spectrum efficiency, good network performance and flat structure, LTE system possesses obvious advantages compared with other wireless telecommunication system. However, spectrum resources are always limited in spite of the high spectrum efficiency of LTE system. As a result, it is of great practical significance to conduct researches on radio resource scheduling which can maximize the spectrum efficiency and the system throughput. In LTE system, the radio resource mainly refers to physical resource block (PRB). However, the radio resource scheduling involves not only the allocation of PRB, but also the feedback of the channel quality indication(CQI) and the adaptive modulation&coding (AMC).The thesis introduces the basic framework and key technologies of LTE system firstly. The classic algorithms and the key technologies in resource scheduling including the feedback of CQI and the AMC technology are investigated here. The advantages and disadvantages of every scheduling algorithm are studied through the Matlab simulation analysis. While users can obtain the highest fairness under the RR algorithm, Max C/I algorithm maximize the system’s throughput. PF algorithm synthesizes the advantages of above two algorithm and gets the best comprehensive performance. According to the hardware platform, the simplified system level simulation is implemented to simulate the adaptive modulation and coding. The detailed processes include three steps. Firstly, the SNR to CQI mapping model is obtained through Matlab simulation. Secondly, based on the mapping model, the receiving terminal feeds back the CQI to the transmitting terminal. Finally, according to the corresponding relation between the CQI and MCS index, the transmitting terminal implements AMC.The software radio platform is briefly introduced in the thesis, based on which, the thesis focuses on the platform implementation scheme of AMC system. The CQI feedback and AMC technology are successfully achieved in the physical layer(DSP module). Eventually, the implementation of the resource scheduling algorithms in DSP chip--MS320C6474is elaborated and the performances results of the scheduling algorithm obtained through DSP are compared with those of the Matlab simulation.