Research On Interference Mitigation Key Methods For LTE-A Uplink System

ABSTRACT:LTE-A system can effectively eliminate the interference between users in the same cell, which is based on the SC-FDMA/OFDMA, but because of the same frequency network, LTE-A system still exist serious inter-cell interference.so the title that how to effectively surpress inter-cell interference is an important hotspot. In order to solve this problem,3GPP proposed coordinate multi-point transmission and reception(CoMP) in the LTE-A system.The basic idea of CoMP is that several points within a cooperation set provide users with service simultaneously so that it can change interference signal into useful one and reduce the inter-cell interference.Compared to the traditional interference suppression technology,CoMP technology can actively control interference between cells instead of passive inhibition. Therefore, as one of the most important methods to suppress inter-cell interference,CoMP has received widespread attention.Compared with downlink CoMP, uplink CoMP technology is still immature, many problems remain to be solved, such as how to effectively receive the uplink data signals is one of the focuses about uplink CoMP.The existing joint reception algorithm cannot guarrante all of high CoMP gain, low system load and low transmission delay, and many other aspects.This paper mainly studies uplink interference suppression techniques about LTE-A, including joint reception algorithm about uplink CoMP and CoMP uplink power control algorithm.The main research work of this paper includes the following three aspects:(1) Based on uplink system level simulation platform of Vienna and China mobile, conduct the secondary development and optimization, analysis and design the network deployment module, channel model module, edge users determine module and resource scheduling module and other important function module, and develop the CoMP interference suppression function module.(2) Based on soft information combining detection technology,put forward an improved joint receptiong algorithm.The algorithm can guarantee higher interference suppression gain, at the same time reduce the system load and transmission delay, so as to improve the overall performance of the system.(3) An effective uplink power control algorithm is put forward.Its main advantage is that it can significantly increase the CoMP gain. The simulation results show that the algorithm can suppress inter-cell interference, and better improve the throughput of the edge users and system capacity.