Abstract: Provided is a multi-UAV continuous movement control method for energy efficient communication coverage. The method includes: determining observation information at a current moment, the observation information including one or more of the following: energy consumption information of a UAV, coverage indication information of users covered by a UAV network facilitated by the UAV or coverage fairness information of the UAV network; determining control information corresponding to the observation information using a DDPG model according to the observation information, wherein the DDPG model is generated from a DDPG algorithm with sample information as an input, the sample information indicating a mapping relationship between sampled observation information and sampled control information; and controlling the UAV to move according to the control information.

Abstract: Provided are a network selection method and an apparatus for integrated cellular and drone-cell networks, where the method includes: acquiring a dynamic network model and a dynamic user model, generating a random event vector according to the dynamic network model and the dynamic user model; generating an action vector according to the random event vector; obtaining an individual utility of each user according to the action vector and the random event vector; constructing a first selection model; obtaining the value of the action probability according the first selection model to determine networks that the users choose to access according to the value of the action probability.

Abstract: A joint search method for UAV multiobjective path planning in an urban low altitude environment first constructs a static safety index map based on static known obstacles. Meanwhile, based on proactively detected obstacles that are not marked on a geographic map by a UAV, the method constructs online a dynamic safety index map. Second, a multiobjective path planning problem is solved using a joint offline and online search method. Moreover, this method first plans offline the least cost path from a starting point to an end point and then invokes the online search scheme to replan online a changed path when the UAV detects unknown obstacles. Thus, the UAV can avoid dynamic obstacles effectively. The online search scheme has a small search space and can quickly replan a safe path for the UAV, thus satisfying the requirement of UAV on the real-time path planning.

Abstract: Provided are a network selection method and an apparatus for integrated cellular and drone-cell networks, where the method includes: acquiring a dynamic network model and a dynamic user model, generating a random event vector according to the dynamic network model and the dynamic user model; generating an action vector according to the random event vector; obtaining an individual utility of each user according to the action vector and the random event vector; constructing a first selection model; obtaining the value of the action probability according the first selection model to determine networks that the users choose to access according to the value of the action probability.

Abstract: Provided is a multi-UAV continuous movement control method for energy efficient communication coverage. The method includes: determining observation information at a current moment, the observation information including one or more of the following: energy consumption information of a UAV, coverage indication information of users covered by a UAV network facilitated by the UAV or coverage fairness information of the UAV network; determining control information corresponding to the observation information using a DDPG model according to the observation information, wherein the DDPG model is generated from a DDPG algorithm with sample information as an input, the sample information indicating a mapping relationship between sampled observation information and sampled control information; and controlling the UAV to move according to the control information.

Abstract: The channel estimation method for millimeter-wave communication includes virtual multipath acquisition and sparse reconstruction. In the virtual multipath acquisition stage, instead of searching the real multipath components (MPCs), the virtual representation of the real MPCs is derived, and the hierarchical search is utilized to acquire the virtual MPCs based on a normal limited-resolution codebook. In the sparse reconstruction stage, the real MPCs are reconstructed from the virtual MPCs acquired in the virtual multipath acquisition stage. An enhanced sub-array scheme is used to design a hierarchical codebook under a strict constant-modulus constraint. The designed codebook can be used for both analog and hybrid beamforming/combining devices. The training overhead of channel estimation and the complexity of the search are significantly reduced, and the size of the dictionary matrix is greatly reduced by exploiting the results of the virtual multipath acquisition.

Abstract: A joint search method for UAV multiobjective path planning in an urban low altitude environment first constructs a static safety index map based on static known obstacles. Meanwhile, based on proactively detected obstacles that are not marked on a geographic map by a UAV, the method constructs online a dynamic safety index map. Second, a multiobjective path planning problem is solved using a joint offline and online search method. Moreover, this method first plans offline the least cost path from a starting point to an end point and then invokes the online search scheme to replan online a changed path when the UAV detects unknown obstacles. Thus, the UAV can avoid dynamic obstacles effectively. The online search scheme has a small search space and can quickly replan a safe path for the UAV, thus satisfying the requirement of UAV on the real-time path planning.

Abstract: The channel estimation method for millimeter-wave communication includes virtual multipath acquisition and sparse reconstruction. In the virtual multipath acquisition stage, instead of searching the real multipath components (MPCs), the virtual representation of the real MPCs is derived, and the hierarchical search is utilized to acquire the virtual MPCs based on a normal limited-resolution codebook. In the sparse reconstruction stage, the real MPCs are reconstructed from the virtual MPCs acquired in the virtual multipath acquisition stage. An enhanced sub-array scheme is used to design a hierarchical codebook under a strict constant-modulus constraint. The designed codebook can be used for both analog and hybrid beamforming/combining devices. The training overhead of channel estimation and the complexity of the search are significantly reduced, and the size of the dictionary matrix is greatly reduced by exploiting the results of the virtual multipath acquisition.