Multidimensional resource allocation strategy for high-speed railway MIMO-OFDM system

With the wide deployment of high-speed railway at more than 300 kilometers per hour, providing various services effectively for users in the train becomes both practical demand and interesting challenge for wireless communication. Resource allocation problem in high-speed railway communication system is one of the key issues to improve the efficiency of resource utilization. In this paper, we propose a multidimensional resource allocation strategy for high-speed railway downlink orthogonal frequency-division multiplexing (OFDM) system with multiple-input multiple-output (MIMO) antennas. Sub-carrier, antenna, time slot, and power are considered jointly, which is modeled as a nonlinear integer programming problem. The effect of the moving speed on inter-carrier interference is analyzed to calculate the transmitted power. The objective is to minimize the total transmitted power while satisfying quality of service requirement of each user. Moreover, optimal and approximate solutions are obtained by linearization and quadratic fitting, respectively. Simulation results have proved that approximate solution has lower total transmitted power than optimal solution while the computation complexity is higher.