School of Communication and Information Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400065, China.
Chongqing Key Laboratory of Optical Communication and Networks, Chongqing 400065, China.
Sensors (Basel). 2020 Dec 31;21(1):217. doi: 10.3390/s21010217.
Cooperative multipoint transmission (CoMP) is one of the most promising paradigms for mitigating interference in cloud radio access networks (C-RAN). It allows multiple remote radio units (RRUs) to transmit the same data flow to a user to further improve the signal quality. However, CoMP may incur redundant data transmission over fronthaul network in the C-RAN. In a C-RAN employing CoMP, a key problem is how to coordinate heterogeneous resource allocation to maximize the cooperation gain while reducing the fronthaul load. In this paper, the cooperation transmission based on a multi-dimensional resource schedule (MRSCT) scheme, jointly considering user association, spectrum resource allocation, and wavelength resource allocation, is firstly envisioned in the underlying C-RAN integrating time and wavelength division multiplexing passive optical network (TWDM-PON) to maximize fronthaul efficiency. Then a two-timescale resource allocation framework including two sub-approaches is established. More specially, the first sub-approach mainly focuses on exploiting reinforcement learning to obtain a wavelength resource allocation strategy to relieve fronthaul traffic load. Moreover, the second sub-approach adopts the overlapping coalition formation game to establish a user-centric cooperative set, where spectrum resources are dynamically allocated to further alleviate the interference issue. The theoretical analysis and simulation results validate the performance of MRSCT scheme on the fronthaul efficiency, user experience, and system service capability.
协作多点传输 (CoMP) 是减轻云无线接入网络 (C-RAN) 中干扰的最有前途的范例之一。它允许多个远程无线电单元 (RRU) 向用户传输相同的数据流量，以进一步提高信号质量。然而，CoMP 可能会在 C-RAN 的前传网络中产生冗余的数据传输。在采用 CoMP 的 C-RAN 中，一个关键问题是如何协调异构资源分配，以最大限度地提高协作增益，同时降低前传负载。在本文中，首先在基于时分波分复用无源光网络 (TWDM-PON) 的底层 C-RAN 中设想了基于多维资源调度 (MRSCT) 方案的协作传输，以最大限度地提高前传效率。然后建立了一个包括两个子方法的两时标资源分配框架。更具体地说，第一个子方法主要侧重于利用强化学习来获得一种波长资源分配策略，以减轻前传流量负载。此外，第二个子方法采用重叠联盟形成博弈来建立以用户为中心的协作集，动态分配频谱资源以进一步缓解干扰问题。理论分析和仿真结果验证了 MRSCT 方案在前传效率、用户体验和系统服务能力方面的性能。
