Optimal Power Allocation in Cache-Aided Non-Orthogonal Multiple Access Systems

Cache-Aided Non-Orthogonal Multiple Access for 5G-Enabled Vehicular Networks

“…However, the receiver structure following the cacheaided NOMA is slightly different [7], [8]. That is, if the signal intended for V 1 is cached at V 2 during the content placement phase, then V 2 can remove the signal corresponding to V 1 directly before decoding its own signal, thereby minimizing the interference.…”

“…However, as mentioned earlier, there are some sporadic results reported on the advantages of cache-aided NOMA in cellular systems. For example, it was shown in [33] that exploited pre-cached contents can reduce/mitigate the incurred interference, while employing SIC for NOMA. An optimum power allocation for the considered network is investigated, aiming to maximize the probability of successful decoding of files at each user.…”

“…However, the simplistic Rayleigh fading conditions were assumed, which is not practically realistic in vehicular networks. Moreover, the model in [33] only considers the full file caching case; that is, the authors assume that in the caching phase, the files are cached as a whole, which is largely restrictive. On the contrary, only a split file caching framework was considered in [34].…”

“…Furthermore, the interference reduction due to caching also helps to reduce the computational complexity of SIC. Although cache-aided NOMA for cellular networks has received attention in the recent literature [33], [34], the available framework is not directly applicable to vehicular networks. This is largely due the following challenges: high mobility, network partitioning, leading to several isolated clusters of nodes, rapidly changing network topology with intermittent connectivity, and the harsh propagation environments.…”

“…The combination of NOMA with MIMO and mmWave communications was recently reported in [4], [5], where significant improvement in spectral efficiency was demonstrated. Recently, in the context of cellular networks, the integration of NOMA and caching was reported in [7] and [8]. To the best of our knowledge, the only work that investigates the performance of cache-aided NOMA systems in the context of vehicular networks is [9].…”