To accommodate the ever-increasing demands for non-safety critical services in vehicular networks, heterogeneous vehicular networks (HVNs) have been proposed and drawn considerable attention. It is known that the performance of HVNs suffers from a shortage of spectrum resource, and the relatively low utilization of licensed spectrum makes the spectrum shortage even worse. To cope with this, by introducing unlicensed spectrum into HVNs, we investigate the spectrum efficiency (SE)-oriented collaborative transmission. The SE for HVNs depends highly on the channel state information (CSI) of the effective communication links which are normally determined by the vehicle pairing. So, we first propose a joint social-physical domain vehicle pairing algorithm (JSPD-VPA), and then formulate an optimization problem to maximize the SE of vehicle-to-everything (V2X) communications while guaranteeing the quality of services (QoS) requirements of cellular users in licensed spectrum and users in unlicensed spectrum. Considering that the formulated problem is NP-Hard problem, to solve it, the formulated problem is decomposed into two subproblems, i.e., spectrum assignment subproblem and power control subproblem. An optimal hypergraph coloring algorithm is proposed to solve the spectrum assignment subproblem, and a low-complexity three-dimensional geometry approach is developed to solve the power control subproblem. Simulation results reveal that the proposed vehicle pairing, spectrum assignment and power control algorithm (VP-SA-PCA) can greatly enhance the SE and outperforms the baselines around 7%-37% within a certain range. Moreover, the superiority of the proposed JSPD-VPA has been validated.

中文翻译：

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异构车载网络中非安全关键服务的车辆配对、频谱分配和功率控制


为了满足车载网络中对非安全关键服务不断增长的需求，异构车载网络（HVN）被提出并引起了广泛关注。众所周知，HVN的性能受到频谱资源短缺的影响，而授权频谱利用率相对较低使得频谱短缺更加严重。为了解决这个问题，通过将非授权频谱引入HVN，我们研究了面向频谱效率（SE）的协作传输。 HVN 的 SE 高度依赖于有效通信链路的信道状态信息 (CSI)，该信息通常由车辆配对确定。因此，我们首先提出一种联合社​​会物理域车辆配对算法（JSPD-VPA），然后制定一个优化问题，以在保证服务质量（QoS）要求的同时最大化车辆到一切（V2X）通信的SE许可频谱中的蜂窝用户和非许可频谱中的用户。考虑到所表述的问题是NP-Hard问题，为了解决该问题，将所表述的问题分解为两个子问题，即频谱分配子问题和功率控制子问题。提出了一种最优超图着色算法来解决频谱分配子问题，并开发了一种低复杂度的三维几何方法来解决功率控制子问题。仿真结果表明，所提出的车辆配对、频谱分配和功率控制算法（VP-SA-PCA）可以极大地提高SE，并在一定范围内优于基线约7%-37%。此外，所提出的 JSPD-VPA 的优越性已经得到验证。