中文摘要：

对高速铁路下行MIMO-OFDM系统中的动态资源分配问题进行研究.联合考虑子载波、天线、时隙和功率,将多维资源分配问题建模为混合整数非线性规划问题.分析移动速度对多普勒频移的影响,并计算子载波间干扰功率.在总发射功率不超过一定阈值的约束条件下,将最大化系统吞吐量作为优化目标.为了降低求解最优化问题的计算复杂度,采用两步求解法得到次优解.首先,在等功率分配的前提下,将子载波、天线和时隙分配给不同用户.然后,根据第1步资源分配的结果,进行功率分配.仿真结果显示,提出的多维资源分配策略与已有策略相比在系统吞吐量方面具有较大的性能提高.

英文摘要：

The dynamic resource allocation problem in high-speed railway downlink orthogonal frequency-division multiplexing（OFDM） systems with multiple-input multiple-output（MIMO） antennas is investigated.Sub-carriers,antennas,time slots,and power are jointly considered.The problem of multi-dimensional resource allocation is formulated as a mixed-integer nonlinear programming problem.The effect of the moving speed on Doppler shift is analyzed to calculate the inter-carrier interference power.The optimization objective is to maximize the system throughput under the constraint of a total transmitted power that is no greater than a certain threshold.In order to reduce the computational complexity,a suboptimal solution to the optimization problem is obtained by a two-step method.First,sub-carriers,antennas,and time slots are assigned to users under the assumption of equal power allocation.Next,the power allocation problem is solved according to the result of the first-step resource allocation.Simulation results show that the proposed multi-dimensional resource allocation strategy has a significant performance improvement in terms of system throughput compared with the existing one.