Recently, orthogonal time frequency space (OTFS) modulation has garnered considerable attention due to its robustness against doubly-selective wireless channels. In this paper, we propose a low-complexity iterative successive interference cancellation based minimum mean squared error (SIC-MMSE) detection algorithm for zero-padded OTFS (ZP-OTFS) modulation. In the proposed algorithm, signals are detected based on layers processed by multiple SIC-MMSE linear filters for each sub-channel, with interference on the targeted signal layer being successively canceled either by hard or soft information. To reduce the complexity of computing individual layer filter coefficients, we also propose a novel filter coefficients recycling approach in place of generating the exact form of MMSE filter weights. Moreover, we design a joint detection and decoding algorithm for ZP-OTFS to enhance error performance. Compared to the conventional SIC-MMSE detection, our proposed algorithms outperform other linear detectors, e.g., maximal ratio combining (MRC), for ZP-OTFS with up to 3 dB gain while maintaining comparable computation complexity.

翻译：近期，正交时频空间（OTFS）调制因其对双选择性无线信道的鲁棒性而受到广泛关注。本文针对零填充OTFS（ZP-OTFS）调制，提出了一种基于迭代逐次干扰消除的最小均方误差（SIC-MMSE）低复杂度检测算法。在所提算法中，信号通过每个子信道多个SIC-MMSE线性滤波器处理的层进行检测，目标信号层的干扰依次通过硬判决或软信息进行消除。为降低计算各层滤波器系数的复杂度，我们还提出了一种新颖的滤波器系数循环利用方法，替代了生成精确MMSE滤波器权重的方案。此外，我们为ZP-OTFS设计了一种联合检测与解码算法以提升误码性能。与传统SIC-MMSE检测相比，所提算法在保持相当计算复杂度的同时，相比其他线性检测器（如最大比合并MRC），在ZP-OTFS系统中可获得高达3 dB的性能增益。