A novel WCDMA uplink capacity and coverage model including the impact of non-ideal fast power control and macro diversity

Author(s):  
K. Hiltunen ◽  
M. Karlsson
Author(s):  
Xiuhua Fu ◽  
Tian Ding ◽  
Rongqun Peng ◽  
Cong Liu ◽  
Mohamed Cheriet

AbstractThis paper studies the communication problem between UAVs and cellular base stations in a 5G IoT scenario where multiple UAVs work together. We are dedicated to the uplink channel modeling and the performance analysis of the uplink transmission. In the channel model, we consider the impact of 3D distance and multi-UAVs reflection on wireless signal propagation. The 3D distance is used to calculate the path loss, which can better reflect the actual path loss. The power control factor is used to adjust the UAV's uplink transmit power to compensate for different propagation path losses, so as to achieve precise power control. This paper proposes a binary exponential power control algorithm suitable for 5G networked UAV transmitters and presents the entire power control process including the open-loop phase and the closed-loop phase. The effects of power control factors on coverage probability, spectrum efficiency and energy efficiency under different 3D distances are simulated and analyzed. The results show that the optimal power control factor can be found from the point of view of energy efficiency.


2019 ◽  
Vol 57 (4) ◽  
pp. 376-384 ◽  
Author(s):  
Ho-Yun Seon ◽  
Ji-Hoon Yang ◽  
Sang-Hun Lee ◽  
Seong-Mi Park ◽  
Sung-Jun Park

In the CTTS system, while transferring the power supply from the grid to the generator, a sudden arc arises, which causes damage to the system. The method proposed in this study reduces this damage. The power state of the generator stage is made equal to the state of the power of the grid in order to prevent the occurrence of a sudden arc. Even if the generator power state is the same with the power state of the generator, an arc can be generated due to a sudden current flow during the transfer. Therefore, the current in the generator stage is controlled to 0 (zero) when transferring, so that the generation of an electrical arc is minimized. In general, when the CTTS system is used for transferring power sources with an emergency generator, the impact from the electrical arc will be momentarily proportional to the amount of the power supplied from the generator to the load. The damage by the arc will make the life of the CTTS system shorter. In order to prevent such damage, a blocking technique using parallel capacitor is constituted. However, this causes arc generation at the time of input. Thus, in this paper, it is proposed to control the effective or ineffective power of the system to zero. To verify the validity of the proposed method, firstly the Powersim simulation was conducted, and after confirming the feasibility based on this, the actual prototype was created and implemented. Zero power control is proposed as a way to improve the stability of CTTS by significantly reducing the generation of an electrical arc. And this technique can help people working on the distributed power or the grid management.


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