An Energy Efficiency Power Allocation Scheme For The4th Generation Mobile Telecommunication Network

With the green house getting worse and worse, the environment pollution is gaining more and more attention. Energy saving is in every country and organization’s mind. The research has shown that the communication networks and equipment count3%of the emission of carbon dioxide in the world. The main emission of the communication network lies in wireless access network. Meanwhile, the base stations consume50%-60%energy of the wireless access network. The energy consumed by the amplifier counts60%-80%in base station. As a result, it is significant and meaningful to decrease energy consumption of sending signals. The4th generation communication, Long Term Evolution (LTE) is the main development direction in the future. As the mobile internet is coming, the demand of data rate of the mobile communication is getting larger and larger. Therefore it is a significant research field to increase the throughput in LTE system. In this paper, a two-level water-filling power allocation scheme based on classification of the traffic is proposed. The power allocation scheme in small cell distributed scene is also been considered.In the two level water-filling scheme(TLWFS), firstly, the traffics are classified into two categories based on the different delay requirements. One is Rate Constrained Traffic (RCT), which is sensitive to the delay, in other words, the delay has great impact on this kind of traffics. Consequently, we have to guarantee RCT while maximizing the energy efficiency. The other one is not as sensitive to the delay as RCT, and we call this kind of traffics as Rate Non-Constrained Traffic (RNCT). Secondly, at the first water-filling level, the high SNR Resource Blocks (RBs) are selected to guarantee the RCT, with traditional water-filling algorithm. Finally, at the second water-filling level, the energy and RBs left are used to transfer the RNCT, with directional water-filling algorithm. Numerical results indicate that the TLWFS works well in LTE system, with the energy consumption decreased by10%with TLWFS, compared to traditional power allocation scheme. In small cell distributed scene, the ZF beamforming is used to eliminate the interference between different cells and the interference between different antennas in one cell. In the parallel sub-channels, the water-filling algorithm is used for power allocating. The simulation results show that water-filling algorithm combined by beamforming technology works well in small cell scene.The contributions of this paper are as follows. We propose a model for this kind of energy efficiency optimization problem. Besides, this paper analyses the optimal solution theoretically. We propose TLWFS for power allocation, which aims to maximize the energy efficiency, meanwhile it can guarantee the QoS requirements. We suit directional water-filling, in LTE system. The power allocation scheme in small cell distributed scene is also been considered, and it works well.