Throughput Optimization of Cooperative Teleoperated UGV Network

Abstract

Cooperative communications among group of teleoperated unmanned ground vehicles (UGVs) allows to exploit spatial diversity in wireless fading channels by relaying signals between each other. Due to the high speed of the UGVs, the nature of the channel environments and the possible co-channel interference, the effect of multipath propagation and the Doppler spread are more pronounced. In this article, we proposed a low complexity dynamic channel assignment (DCA) technique with adaptive modulation and coding (AMC) strategy to allocate the available bandwidth over a number of communications links in a cooperative 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 in a 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. In this article, the outage is defined as the percentage of time the links are incapable of supporting a minimum required transmission rate which is 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. The authors assum the links in the network to be Rayleigh faded and we used a finite state Markov chain (FSMC) for their modeling. Using Monte Carlo simulation, we showed that the proposed DCA approach in a cooperative UGVs provides significant gain in the overall throughput and reduction in the outage probability compared to the static channel assignment (SCA).