针对现有正交频分多址(OFDMA)系统初始测距算法检测性能不佳以及复杂度过高的问题，该文提出一种低复杂度迭代干扰消除的多用户初始测距算法。该算法采用迭代并行干扰消除方法，在接收端按照最大功率准则并行检测活动测距用户的有效径，利用估计出的有效径参数信息来减小信道估计中的干扰，再通过重构和并行消除多用户测距信号。计算机仿真结果表明，与连续多用户检测(SMUD)干扰抵消算法相比，当信噪比为9 dB，且一个测距时隙内测距用户数为8时，所提算法的复杂度大约是SMUD的25%，检测性能大约提高了5%。%To solve the issues of the low detection performance and high computational complexity of the available initial ranging algorithms for Orthogonal Frequency Division Multiple Access (OFDMA) systems, a low-complexity initial ranging algorithm with iterative interference cancellation is presented. By using the Parallel Interference Cancellation (PIC) scheme in an iterative fashion, the proposed algorithm detects parallelly the valid paths of active users by means of the strongest power criterion at the receiver, and mitigates the channel estimation interference by employing the parameters estimation of the valid paths. Then it rebuilds and cancels parallelly the detected multiusers’ signals. Simulation results show that when there are 8 initial ranging users in one ranging time slot and the signal noise ratio is 9 dB, the computational complexity of the proposed algorithm is approximately 25% of that of the Successive MultiUser Detection (SMUD) with interference cancellation algorithm, and the detection performance is improved by 5%compared with SMUD.
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