Performance Optimization for D2D Communications With Opportunistic Relay and Physical-Layer Network Coding
Performance Optimization for D2D Communications With Opportunistic Relay and Physical-Layer Network Coding
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DOI：
10.1109/tvt.2019.2947021
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发表时间：
2019-12
影响因子：
6.8
通讯作者：
Shijun Lin;Yong Li;Haichuan Ding;Yuguang Fang;Jianghong Shi
中科院分区：
文献类型：
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作者：
Shijun Lin;Yong Li;Haichuan Ding;Yuguang Fang;Jianghong Shi
在本文中，我们研究了联合信号干扰噪声比（SINR）阈值优化和资源分配，以最大化设备到设备（D2 D）通信的总速率，同时仍然保留活动蜂窝用户（CU）的速率要求，当非活动CU在三种操作模式下用作机会中继时：而不使用网络编码（NNC）、使用传统的高层网络编码（HNC）以及使用物理层网络编码（PNC）。在瑞利衰落下，我们表明，给定的中继的选择，这种无中继方案，NNC，HNC和PNC机会中继方案的总速率最大化可以制定为一个混合整数非线性规划（MINLP），这是NP-硬一般。为了找到MINLP的解决方案，我们提出了两步方法来解决该问题：1）对于D2 D对和CU的每个可能配对，我们导出最佳SINR阈值以在满足CU的速率要求的同时获得D2 D对的最大传输速率; 2）在第一步中，基于D2 D对对于每个可能配对的最大传输速率，我们开发了一种二分匹配方法来找到D2 D对的最佳配对CU。最后，根据MINLP的解，我们提出了一种迭代的中继选择算法，以找出可以进一步提高D2 D通信的和速率的中继。大量的仿真结果表明，与没有中继的情况下，NNC，HNC和PNC机会中继方案实现了最大的性能提高106%，138%和168%，分别。
In this paper, we investigate the joint signal to interference plus noise ratio (SINR) thresholds optimization and resource allocation to maximize the sum-rate of Device-to-Device (D2D) communications while still retaining the rate requirements for active cellular users (CUs), when the inactive CUs are used as opportunistic relays under three operational modes: without using network-coding (NNC), using traditional high-layer network-coding (HNC), and using physical-layer network-coding (PNC). Under Rayleigh fading, we show that, given the selections of relays, this sum-rate maximization in no-relay scheme, NNC, HNC, and PNC opportunistic relay schemes can be formulated as a mixed integer non-linear programming (MINLP), which is NP-hard in general. To find the solution to the MINLP, we propose a two-step approach to solve the problem: 1) for each possible pairing of a D2D pair and a CU, we derive the optimal SINR thresholds to obtain the maximum transmission rate of the D2D pair while satisfying the rate requirement of the CU; 2) based on the maximum transmission rates of D2D pairs for each possible pairing in the first step, we develop a bipartite-matching method to find the optimal pairing CUs for D2D pairs. Finally, according to the solution to the MINLP, we propose an iterative relay selection algorithm to find out the relays that can further improve the sum-rate of D2D communications. Extensive simulation results demonstrate that, compared with the scenario without relaying, the NNC, HNC, and PNC opportunistic relay schemes achieve a maximum performance enhancement of 106%, 138%, and 168%, respectively.