认知无线电下蜂窝与D2D多播联合资源分配

0 下载量 137 浏览量 更新于2024-07-15 收藏 1.31MB PDF 举报
本文标题"Joint Resource Allocation for Cellular and D2D Multicast Based on Cognitive Radio"探讨了在认知无线网络环境下,如何有效地整合蜂窝网络和设备对设备(D2D)通信的资源,以支持多播服务。多播作为一种高效的传输模式,对于未来的移动社交接触服务具有重要意义,特别当它结合D2D技术时,能够显著提升系统容量和频谱效率。 文章首先强调了D2D通信在无线网络中的潜力,它通过共享蜂窝网络的频谱资源,能够在不增加额外基础设施的情况下,实现设备间的直接连接,从而提高了数据传输的速率和覆盖范围。在这个背景下,多播传输被赋予了新的价值,因为它可以同时向多个接收终端发送相同的数据,大大减少了重复的带宽消耗。 作者们关注的核心问题是联合资源分配策略,这是在认知无线网络中实现蜂窝网络和D2D多播服务的关键。他们提出了一种优化方法,旨在最大化系统整体性能,比如吞吐量、能量效率或服务质量(QoS),同时考虑到不同用户的需求和频谱的动态可用性。这种策略可能包括频谱感知、协作调度、功率控制以及可能的多层网络架构优化。 具体的研究内容可能包括: 1. 认知无线电特性:文中可能介绍了认知无线电如何动态地识别和利用未被充分利用的频谱资源,这对于在D2D多播中平衡蜂窝网络与非授权用户的利益至关重要。 2. 协同资源管理:通过协调蜂窝基站和D2D设备的传输,可能设计了一种算法来优化频谱、时间和功率分配,以确保多播信号的高效传播。 3. QoS保障:文章可能会讨论如何在多用户环境中保持公平性和服务质量,防止某些用户的干扰导致整体性能下降。 4. 仿真与评估:通过理论分析和计算机仿真,可能展示了联合资源分配策略在实际网络环境中的效果,包括性能提升、频谱利用率等关键指标。 5. 挑战与未来方向:文中可能还提到了当前面临的挑战,如频谱监管、安全问题以及如何进一步提高多播D2D的普适性和效率。 这篇研究论文提供了在认知无线网络环境中,通过优化资源配置来实现蜂窝网络与D2D多播协同工作的理论框架和技术方法,对于推动未来移动通信系统的高效和可持续发展具有重要的参考价值。
112 浏览量

Algorithm 1: The online LyDROO algorithm for solving (P1). input : Parameters V , {γi, ci}Ni=1, K, training interval δT , Mt update interval δM ; output: Control actions 􏰕xt,yt􏰖Kt=1; 1 Initialize the DNN with random parameters θ1 and empty replay memory, M1 ← 2N; 2 Empty initial data queue Qi(1) = 0 and energy queue Yi(1) = 0, for i = 1,··· ,N; 3 fort=1,2,...,Kdo 4 Observe the input ξt = 􏰕ht, Qi(t), Yi(t)􏰖Ni=1 and update Mt using (8) if mod (t, δM ) = 0; 5 Generate a relaxed offloading action xˆt = Πθt 􏰅ξt􏰆 with the DNN; 6 Quantize xˆt into Mt binary actions 􏰕xti|i = 1, · · · , Mt􏰖 using the NOP method; 7 Compute G􏰅xti,ξt􏰆 by optimizing resource allocation yit in (P2) for each xti; 8 Select the best solution xt = arg max G 􏰅xti , ξt 􏰆 and execute the joint action 􏰅xt , yt 􏰆; { x ti } 9 Update the replay memory by adding (ξt,xt); 10 if mod (t, δT ) = 0 then 11 Uniformly sample a batch of data set {(ξτ , xτ ) | τ ∈ St } from the memory; 12 Train the DNN with {(ξτ , xτ ) | τ ∈ St} and update θt using the Adam algorithm; 13 end 14 t ← t + 1; 15 Update {Qi(t),Yi(t)}N based on 􏰅xt−1,yt−1􏰆 and data arrival observation 􏰙At−1􏰚N using (5) and (7). i=1 i i=1 16 end With the above actor-critic-update loop, the DNN consistently learns from the best and most recent state-action pairs, leading to a better policy πθt that gradually approximates the optimal mapping to solve (P3). We summarize the pseudo-code of LyDROO in Algorithm 1, where the major computational complexity is in line 7 that computes G􏰅xti,ξt􏰆 by solving the optimal resource allocation problems. This in fact indicates that the proposed LyDROO algorithm can be extended to solve (P1) when considering a general non-decreasing concave utility U (rit) in the objective, because the per-frame resource allocation problem to compute G􏰅xti,ξt􏰆 is a convex problem that can be efficiently solved, where the detailed analysis is omitted. In the next subsection, we propose a low-complexity algorithm to obtain G 􏰅xti, ξt􏰆. B. Low-complexity Algorithm for Optimal Resource Allocation Given the value of xt in (P2), we denote the index set of users with xti = 1 as Mt1, and the complementary user set as Mt0. For simplicity of exposition, we drop the superscript t and express the optimal resource allocation problem that computes G 􏰅xt, ξt􏰆 as following (P4) : maximize 􏰀j∈M0 􏰕ajfj/φ − Yj(t)κfj3􏰖 + 􏰀i∈M1 {airi,O − Yi(t)ei,O} (28a) τ,f,eO,rO 17 ,这个算法中基于模型的DRL算法和无优化的DRL算法和DNN深度学习都各体现在哪

137 浏览量