| ID | 原文 | 译文 |
| 51737 | 多年来一直在使用的船舶自动识别系统(AIS)作为一种海上监视和导航的通信系统， | The Automatic Identification System(AIS), which has been used for many years, is a communication system for maritime surveillance and navigation, |
| 51738 | 其服务范围被限制在40海里。 | and its service scope is limited to 40 nautical miles. |
| 51739 | 近年来，一种新的基于卫星的AIS被提出，该系统能提供全球覆盖服务， | In recent years, a new satellite-based AIS has been proposed, which can provide global coverage services. |
| 51740 | 然而其存在由相对卫星/船舶运动引起的频率偏移问题。 | However, it encounters frequency offset caused by relative satellite/ship motion. |
| 51741 | 为了更好地解决这一问题，文章提出了一种新的基于多普勒频移估计算法的星载多普勒频移估计算法，利用二阶矩阵及四阶矩阵等代数运算，从信号中提取多普勒频移，并给出了估计表达式。 | In order to solve this problem, this paper proposes a new Doppler shift estimation algorithm. The second-order matrix and the fourth-order matrix are used to extract the doppler shift from the signal, and the estimation expression is then provided. |
| 51742 | 最后，通过数值仿真验证了该算法的有效性，仿真结果还验证了该算法的优越性。 | Finally, the validity of the method is verified by numerical simulation, and the superiority of the method is verified by simulation results. |
| 51743 | 对于上行免调度的多用户共享接入(MUSA)方案，用户具备随机突发接入系统的特性， | For the uplink grant-free Multi-User Shared Access(MUSA) scheme, the user has the characteristics of access system randomly, |
| 51744 | 用户信号具有稀疏性，可利用压缩感知的相关算法进行多用户检测。 | and the user signal has sparseness, which can use the relevant algorithm of compression perception for multi-user detection. |
| 51745 | 针对活跃用户数未知的情况，文章提出了基于验证误差的正交匹配追踪(VE-OMP)多用户检测算法。 | In view of the unknown number of active users, a multi-user detection algorithm based on Validation Error Orthogonal Matching Pursuit(VE-OMP) is proposed. |
| 51746 | 所提算法利用误差在迭代次数等于用户稀疏度时能够达到最小值来估计稀疏度， | The proposed algorithm can estimate the sparsity by using the error to reach the minimum value when the number of iterations is equal to the user's sparsity. |