Research On EICIC In LTE-A Heterogeneous Networks

With the rapid development of mobile Internet and the fast growth of urban population, there will be forming an increasing number of communication hotspots and communication blackout. Using traditional e NB to cover hotspots and blackout is not only expensive, but also have mutual interference with the existing base. To reach the purpose of coverage of hotspots and blackout Pico is introduced in the LTE-A, while because of the strong interference of e NB it can’t be effective for coverage of hotspots. Cell Range Extension(CRE) technique allows more users to access to the Pico, but the users within Pico extended range have poor channel quality and low throughput. With the analysis above, power control and e ICIC of time domain are studied in this paper.Firstly, the key technology of LTE-A Heterogeneous Networks(Het Nets) is introduced, and the interference scenario and Enhanced Inter-Cell Interference Coordination(e ICIC) technology of LTE-A Het Nets are analyzed. Secondly, the operating e ICIC with Low Power Almost Blank Subframes(LP-ABS) is discussed and the performance of LP-ABS with different parameters in different scenarios is simulated. With the research aboved, an adaptive LP-ABS technology based on the ratio and power of the LP-ABS subframes is proposed. Adjust the ratio and power of the LP-ABS subframes of every sector dynamically according to the ratio of user access and interference scenarios in every simulation. Simulation results show that the adaptive LP-ABS technology is not only able to ease the strong interference of the present sector Macro on Pico very well, but also effectively improve the user fairness and communications stability. Finally, with the research on the advantages and disadvantages of adaptive LP-ABS technology, an e ICIC algorithm based on LP-ABS and power control is proposed. This algorithm consists of Pico coordinated power control in same sector and adaptively revised LP-ABS. Simulation results show that although the algorithm reduces the throughput of Macro users and Pico users which have good channel quality, the throughput of Pico users with poor channel quality is improved. Besides, the communication users in present sector are more stable and fairer.