Interference management by exploiting cached files at users

Kaiyang Guo, Chenyang Yang, Tingting Liu

Abstract: In this paper, we strive to improve the throughput of wireless networks by exploiting the pre-cached files at user end to manage interference. We employ network-coded multicast (NCM) to help cancel multi-user interference, and reconstructed interference cancellation (RIC) to help cancel inter-cell interference. Because inter-cell interference may not be thoroughly canceled by RIC, base station (BS) muting is used to coordinate the residual strong interference. We jointly optimize user association and BS muting to maximize the number of users simultaneously served by a system using NCM and RIC with any given caching policy. Owing to the complex relation among BS muting, user association, NCM, and RIC, the formulated problem is NP-hard. By transforming the problem into the well-known maximal independent set problem with constructed conflict graph, the global optimal solution can be found efficiently with graph theory methods. Simulation results show that the proposed transmission strategy achieves a remarkable performance gain.