Joint Path Planning and Spectrum Allocation for Mobile Users in Uplink Wireless Networks

Wireless networks have greatly facilitated people's lives, enabling them to maintain smooth communication while moving. Two problems, i.e., path planning and spectrum allocation, are involved when moving and communication occur simultaneously. However, in the above scenario, the problems are different from their classic versions. Specifically, besides geographical barriers, the obstacles in moving also contain regions with spectral congestion, which may lead to communication interruptions. In consequence, the approaches of detouring and spectrum reallocation should be jointly applied to guarantee that the user can quickly reach their destinations without communication quality degradation. Unfortunately, most current works studied the two problems independently and thereby can hardly address the performance of the two aspects simultaneously. To remedy this, we study a joint path planning and spectrum allocation problem here. By jointly determining the movement and the spectrum for each user in each step, we aim to strike a balance among quick destination reach, reliable quality-of-service (QoS) guarantee, and minimum number of spectrum switching. The principle of joint design is that each user tries to move as directly as possible toward its destination while minimizing the likelihood of triggering spectrum switches for other users to achieve their QoS thresholds. To address this, we formulate two problems, i.e., the direction search problem and the spectrum reallocation problem. Considering that the two problems need to be frequently visited in joint design, we develop two low-complexity algorithms for them, ultimately achieving an efficient algorithm for joint path planning and spectrum allocation.