NOMA中的SS-CPM卫星信号捕获算法

调制指数大于1的扩频连续相位调制(spread spectrum continuous phase modulation, SS-CPM)信号是一种极具潜力的卫星信号调制方案, 然而其多峰特性容易导致非正交多址接入(non-orthogonal multiple access, NOMA)条件下的错误捕获。针对这一问题, 本文建立基于NOMA的SS-CPM信号模型, 提出一种基于状态转换的碰撞跳跃检测算法, 分析所提算法在不同发射功率、用户数、相对时延以及调制指数下的捕获性能。仿真结果表明, 所提算法适用于NOMA条件下的SS-CPM信号捕获, 且用户数较少、发射功率相近, 相对时延较大或调制指数较小时, 具有更优的捕获性能。

SS-CPM satellite signal acquisition algorithm in NOMA

Spread spectrum continuous phase modulation (SS-CPM) signal with the modulation index greater than 1 is a potential satellite signal modulation scheme. However, the multi-peak characteristics under the non-orthogonal multiple access (NOMA) can lead to false acquisition. Aiming at the problem of false acquisition, this paper establishes the SS-CPM signal model based on NOMA, and proposes a collision jump detection algorithm based on state transition. In addition, this paper analyzes the acquisition performance of the proposed algorithm under different transmission power, the number of users, relative time delay, and modulation index. The simulation results show that the proposed algorithm is suitable for SS-CPM signal acquisition in NOMA. The acquisition performance of the proposed algorithm is better when the number of users is small, the transmission power is similar, the relative time delay is large or the modulation index is small.