Research And Implementation Of Interference Management Policies On LTE/LTE-Advanced MAC Layer

Both LTE and LTE-Advanced adopts OFDMA in order to meet the requirement of data transmission on large bandwidth. In OFDMA systems, the data of users in the same cell is transmitted on different subcarriers, and adjacent cells share the same system bandwidth. Although OFDM is able to efficiently mitigate intra-cell interference, the inter-cell interference it brings is much more intense. Therefore, ICI becomes a key factor influencing the system capacity. In order to enhance the cell-edge throughput and the system frequency spectrum utilization, it is important to mitigate ICI. Thus, ICI management politics becomes a currently hot research point. This paper is focusing on the ICI management politics on LTE/LTE-Advanced MAC layer. Besides, the author introduces the designed SDR based software platform of LTE MAC layer and the Vxworks based hardware platform of LTE-Advanced MAC layer.This paper is based on the three projects the author participated:1) National Natural Science project——Research on IMT-Advanced CoMP Technology; 2) Cooperative project——Research on LTE MAC over Wireless Network Cloud; 3) Cooperative project——Research on LTE MAC. Based on the above three projects, the main content of this paper is concluded as follows:(1) A novel distributed QoS-guaranteed ICIC scheme for LTE is proposed. We demonstrate through simulations that the proposed scheme provides fine robustness against ICI and can enhance both the network and cell-edge throughputs via a few interactions between eNBs through the X2 interface, making it feasible in LTE because it is distributed.(2) During the project of Research on LTE MAC over Wireless Network Cloud, Based on the network cloud computing platform and the multi-core processing technology of the cooperative company, the author designed the implementation architecture of the LTE MAC layer, and complete the simulation platform base on C language. Based on the requirements of LTE, the designed MAC layer provides the three functions:1) support of end-to-end QoS; 2) MAC data format design; 3) Mapping between logical channels and transport channels. The designed system can be used to implement the verification of LTE MAC related technologies and so on.(3) In the CoMP project, the author was in charge of the design of the implementation architecture of the MAC layer of the hardware verification system. The designed implementation architecture of the LTE MAC layer includes:the overall implementation structure, the implementation diagram of the transmitter and the receiver, and the software functional module. The software implementation is based the the Vxworks OS, and the hardware implementation is based on the Virtex FPGA. The designed MAC implementation architecture can be used as basis for further development of CoMP systems.