Browsing by Author "Shi, Lei"

Now showing 1 - 4 of 4
  • Thumbnail Image
    The Mobile Base Station Strategy for Wireless Networks With Successive Interference Cancellation
    Shi, Lei; Hu, Yun; Xu, Juan; Shi, Yi; Ding, Xu (IEEE, 2019)
    Successive interference cancellation (SIC) and mobile base stations (MBSs) have been separately exploited to effectively collect data in wireless networks. This paper aims to jointly optimize SIC and MBSs movement to minimize MBS's data collection time for given data. First, we design a DPS algorithm for finding some dominating points (good locations for an MBS) in a two-dimensional area. Based on these dominating points, we build a suitable trajectory for MBS's traveling. Then, we divide the whole traveling path into many path parts and then allocate one or several time slots for each path part. In each time slot, we design a farthest-node-allocation (FNA) algorithm for scheduling node transmissions and determining the MBS's moving speed. The simulation results show that the proposed algorithm can significantly reduce the MBS's data collection time than the scheme without using the SIC.
  • Thumbnail Image
    A New Role for an Old Antimicrobial: Lysozyme c-1 Can Function to Protect Malaria Parasites in Anopheles Mosquitoes
    Kajla, Mayur K.; Shi, Lei; Li, Bin; Luckhart, Shirley; Li, Jianyong; Paskewitz, Susan M. (PLOS, 2011-05-06)
    Background Plasmodium requires an obligatory life stage in its mosquito host. The parasites encounter a number of insults while journeying through this host and have developed mechanisms to avoid host defenses. Lysozymes are a family of important antimicrobial immune effectors produced by mosquitoes in response to microbial challenge. Methodology/Principal Findings A mosquito lysozyme was identified as a protective agonist for Plasmodium. Immunohistochemical analyses demonstrated that Anopheles gambiae lysozyme c-1 binds to oocysts of Plasmodium berghei and Plasmodium falciparum at 2 and 5 days after infection. Similar results were observed with Anopheles stephensi and P. falciparum, suggesting wide occurrence of this phenomenon across parasite and vector species. Lysozyme c-1 did not bind to cultured ookinetes nor did recombinant lysozyme c-1 affect ookinete viability. dsRNA-mediated silencing of LYSC-1 in Anopheles gambiae significantly reduced the intensity and the prevalence of Plasmodium berghei infection. We conclude that this host antibacterial protein directly interacts with and facilitates development of Plasmodium oocysts within the mosquito. Conclusions/Significance This work identifies mosquito lysozyme c-1 as a positive mediator of Plasmodium development as its reduction reduces parasite load in the mosquito host. These findings improve our understanding of parasite development and provide a novel target to interrupt parasite transmission to human hosts.
  • Thumbnail Image
    Optimal Base Station Placement for Wireless Sensor Networks with Successive Interference Cancellation
    Shi, Lei; Zhang, Jianjun; Shi, Yi; Ding, Xu; Wei, Zhenchun (MDPI, 2015-01-14)
    We consider the base station placement problem for wireless sensor networks with successive interference cancellation (SIC) to improve throughput. We build a mathematical model for SIC. Although this model cannot be solved directly, it enables us to identify a necessary condition for SIC on distances from sensor nodes to the base station. Based on this relationship, we propose to divide the feasible region of the base station into small pieces and choose a point within each piece for base station placement. The point with the largest throughput is identified as the solution. The complexity of this algorithm is polynomial. Simulation results show that this algorithm can achieve about 25% improvement compared with the case that the base station is placed at the center of the network coverage area when using SIC.
  • Thumbnail Image
    Optimize the Communication Cost of 5G Internet of Vehicles through Coherent Beamforming Technology
    Wu, Lan; Xu, Juan; Shi, Lei; Shi, Yi; Zhou, Wenwen (Hindawi, 2021-05-17)
    Edge computing, which sinks a large number of complex calculations into edge servers, can effectively meet the requirement of low latency and bandwidth efficiency and can be conducive to the development of the Internet of Vehicles (IoV). However, a large number of edge servers mean a big cost, especially for the 5G scenario in IoV, because of the small coverage of 5G base stations. Fortunately, coherent beamforming (CB) technology enables fast and long-distance transmission, which gives us a possibility to reduce the number of 5G base stations without losing the whole network performance. In this paper, we try to adopt the CB technology on the IoV 5G scenario. We suppose we can arrange roadside nodes for helping transferring tasks of vehicles to the base station based on the CB technology. We first give the mathematical model and prove that it is a NP-hard model that cannot be solved directly. Therefore, we design a heuristic algorithm for an Iterative Coherent Beamforming Node Design (ICBND) algorithm to obtain the approximate optimal solution. Simulation results show that this algorithm can greatly reduce the cost of communication network infrastructure.