Throughput Optimization of Cooperative Teleoperated UGV Network

Cooperative communications among a group of teleoperated unmanned ground vehicles (UGVs) allows to exploit spatial diversity in wireless fading channels by relaying signals between them. Due to the high speed of the UGVs, the nature of the channel environments and possible co-channel interference, the effect of multipath propagation and Doppler spread are more pronounced. In this paper, we propose a low complexity relay transmission dynamic channel assignment (DCA) technique with adaptive modulation and coding (AMC) strategy for allocating the available bandwidth over a number of communications links in a UGV network. In many processing algorithms and transmission protocols reported in the literature, performance improvement in terms of system throughput and reliability has been demonstrated. The proposed DCA with AMC over cooperative UGV network has two objectives. First, to maximize the overall throughput of the cooperative UGV network and second, to significantly reduce the probability of outage in the system. The outage here is defined as the percentage of time the links are incapable of supporting a minimum required transmission rate determined by the application. The DCA approach is formulated in terms of a binary optimization problem that is solved using the branch-and-bound method. We assume that the links in the network are Rayleigh faded and we use a finite state Markov chain (FSMC) for their modeling. Using Monte Carlo simulation, we show that the proposed DCA approach in cooperative UGVs provides a significant gain in the overall throughput and reduction in the outage probability compared to the static channel assignment (SCA).