Resource allocation for on-demand multimedia services in high-speed railway wireless networks

With the rapid development of high-speed railway (HSR) system, there is an increasing demand on providing high throughput and continuous multimedia (CM) services for HSR passengers. In this paper, we investigate the downlink resource allocation problem for on-demand CM services in HSR OFDMA systems with a cellular/infostation integrated network architecture. The resource allocation problem is formulated as a two-stage optimization programming, which aims at maximizing the total reward of delivered services then minimizing the weighted total number of cumulative discontinuity packets over the trip of the train. An equivalent one-stage programming is proposed to resolve the difficulty of multi-stage optimization. The resultant mixed integer programming (MIP) is NP-hard in general, we thus reformulate it as a sparse ℓ₀-minimization problem and then relax it to a linear programming (LP). Furthermore, a reweighted ℓ₁-minimization technique is applied to improve the system performance. Simulation results are provided to validate the proposed algorithms.