Detection of symbol-asynchronous uplink NOMA with imperfect time offsets
Detection of symbol-asynchronous uplink NOMA with imperfect time offsets
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DOI：
10.1049/iet-com.2019.0871
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Jingmin Liu;Ying Li;Yue Sun
中科院分区：
文献类型：
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作者：
Jingmin Liu;Ying Li;Yue Sun
考虑符号异步上行链路非正交多址（NOMA）模型，其中Kusers根据其本地时钟将码字传输到公共接收器。由于复杂的用户位置和动态的传输环境，基站(BS)并不总是能够获得用户的准确时间偏移。为了保证系统的效率，设计了基于迭代检测的线性最小均方误差算法和部分消息传递（P-MP）算法。信号干扰加噪声比也用于分析估计时间偏移对 P-MP 算法的影响。仿真结果表明，当估计误差的方差为 时，具有不完全时间偏移的符号异步 NOMA 系统可以实现与 NOMA 系统相同甚至更好的误码率性能。
A symbol‐asynchronous uplink non‐orthogonal multiple access (NOMA) model is considered, whereKusers transmit codewords to a common receiver according to their local clocks. As the complicated user location and the dynamic transmission environment, the exact time offsets of users are not always available at the base station (BS). To ensure the efficiency of the system, linear minimum mean square error algorithm and partial message passing (P‐MP) algorithm are designed based on iterative detection. The signal to interference plus noise ratio is also applied to analysis the effect of estimated time offsets on the P‐MP algorithm. Then simulation results show that when the variance of estimation error is, the symbol‐asynchronous NOMA systems with imperfect time offsets can achieve the same or even better bit error rate performance than the NOMA system.