| 摘要: |
| 采用信息年龄(Age of Information，AoI)作为双向通信信息新鲜度度量的性能指标。结合非正交多址接入（Non-orthogonal Multiple Access,NOMA）技术、物理层网络编码（Physical-layer Network Coding,PNC）技术、自动重传请求（Automatic Repeat Request，ARQ）协议等，构建了一个双向NOMA四节点中继协作系统，设计了双向叠加编码中继协作(Superposition Coding Relay-assisted，SC-RA) 传输策略以及双向联合叠加编码和物理层网络编码中继协作（Joint Physical-layer Network Coding and Superposition Coding Relay-assisted，JNSC-RA）传输策略，分别采用四时隙与三时隙传输机制，在一个传输周期内，通过两个中继节点协作来实现两组信息的传输。分别对每种策略下的平均信息年龄(Average Age of Information，AAoI)进行了分析，并对解析表达式进行了建模。仿真表明，双向SC-RA策略更适合对称信道，AAoI可降低9.09%，且在功率分配因子为0.9时，AAoI取得最优解；双向JNSC-RA策略更适合非对称信道，AAoI可降低10%，且在信噪比大于8 dB时较双向SC-RA策略对AAoI的降低明显。 |
| 关键词: 非正交多址接入(NOMA) 双向通信 信息年龄 叠加编码 自动重传请求协议 |
| DOI：10.20079/j.issn.1001-893x.240118002 |
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| 基金项目:国家自然科学基金资助项目(62261048) |
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| Analysis of Information Freshness in a Bidirectional NOMA Four-node Relay Cooperation System |
| NIU Xiayang,JIA Xiangdong,ZHANG Liang,XUE Kailai |
| (1.College of Computer Science and Engineering,Northwest Normal University,Lanzhou 730070,China;2.Wireless Communication Key Lab of Jiangsu Province,Nanjing University of Posts and Telecommunications,Nanjing 210003,China) |
| Abstract: |
| To measure the freshness of bidirectional communication,the age of information(AoI) is adopted as a performance metric.A bidirectional non-orthogonal multiple access(NOMA) four-node relay cooperation system is constructed,integrating NOMA technology,physical-layer network coding(PNC) technology,and automatic repeat request(ARQ) protocol.Two transmission strategies are designed:the bidirectional superposition coding relay-assisted(SC-RA) transmission strategy and the bidirectional joint physical-layer network coding and superposition coding relay-assisted(JNSC-RA) transmission strategy.These strategies utilize four-slot and three-slot transmission mechanisms,respectively,to achieve the transmission of two sets of information through cooperation between two relay nodes within a transmission cycle.The average age of information(AAoI) is analyzed for each strategy,and analytical expressions are derived.The simulation results show that the bidirectional SC-RA strategy is more suitable for symmetric channels,and the AAoI can be reduced by 9.09%,and the optimal solution is obtained when the power distribution factor is 0.9.The bidirectional JNSC-RA strategy is more suitable for asymmetric channels,and the AAoI can be reduced by 10%.Moreover,when the signal-to-noise ratio is greater than 8 dB,the AAoI is significantly reduced by the bidirectional SC-RA strategy. |
| Key words: non-orthogonal multiple access(NOMA) two-way communication age of information superposition coding automatic retransmission request |
《电讯技术》编辑部 