Research On LTE-Hi System Higher Order Modulation And Link-Level Simulation Evaluation

Mobile communication has been indispensable in people's daily life. To meet the increasing demand of multimedia service, especilally for the vast majority of data service in the indoor area.3GPP has proposed LTE-Hotspot Indoor System. In order to promote the commercialization of high-order modulation technology in LTE-Hi system, it is urgent to study the key technology involved in the introduction of high-order modulation, and to verify the LTE-Hi system throughput gain when introduced high-order modulation technology (256QAM)intothe good indoor channel environment.In this paper, the key technologies of LTE-Hi system high-order modulation and link simulation evaluation are studied. An effective SNR combining method for high - order modulation is given by simulation and optimization. The simulation platform is built under the link self-adaptive condition. The multi-dimensional simulation and analysis are done in LTE-Hi static and dynamic channel environment. The simulation results can provide the basis for the testing work. Moreover, the performance of MIESM in HARQ link abstraction is studied, and the formula of high order modulation is modified by simulation. The major contributions of this paper are as follows:Firstly, the high-order modulation (256QAM) brings the challenge to the original adaptive modulation and coding, in which the effective signal-to-noise mapping (ESM) is an important part of CQI reporting. In order to make EESM and MIESM accurately applied to high Order modulated OFDM system, the parameter optimization scheme is designed and the optimized parameter values are obtained. By analyzing the advantages and disadvantages of the two algorithms, it is concluded that MIESM is a signal-to-noise ratio combining method suitable for high order modulation.Secondly, in order to complete the link evaluation of high-order modulation in LTE-Hi system, a link simulation platform is built. By analyzing the simulation results of TM2 / TM3 / TM adaptive and LOS /NLOS transmission modes, the gain of the high-order modulation technique under the LTE-Hi static channel and the required information are given.Noise ratio, the feasibility of introducing 256QAM into the dynamic channel is analyzed.Finally, it verifies the accuracy of the MITSM-based HARQ system's link abstraction in high-order modulation. It is found that with the increase of the modulation order and the coding rate, the link aberration will increase.The amount of offset compensation under each MCS is obtained by a large number of simulations. The correction of the final formula is completed. The parameters and corrections obtained by the calculation and simulation provide the basis for system level simulation of HARQ.