论文标题
零填充OTFS Systems的低复杂性迭代耙决策反馈均衡器
Low Complexity Iterative Rake Decision Feedback Equalizer for Zero-Padded OTFS systems
论文作者
论文摘要
本文介绍了最近提出的正交时间频率空间（OTFS）调制方案的线性复杂性迭代镜头检测器。基本思想是使用最大比率组合（MRC）在延迟多普勒网格中提取并连贯地结合传输符号的接收多径成分，以改善组合信号的SNR。我们通过将防护符号或零填充（ZP）放置在延迟多普勒网格中，并利用通道矩阵块的产生的循环属性，以简单向量形式重新重新重新以简单的向量形式重新重新重新制定输入输出关系。使用此矢量输入输出关系，我们提出了基于MRC的低复杂性迭代决策反馈均衡器（DFE）。拟议检测器的性能和复杂性与最先进的消息传递检测器的状态相比。还提出了一种基于MRC的替代时间域检测器，以更快地检测。我们进一步提出了耙子检测器中基于高斯 - 西德尔的过度释放参数，以提高迭代检测的性能和收敛速度。我们还展示了如何将MRC检测器与外部误差校正代码相结合，以作为涡轮DFE方案的操作，以进一步改善误差性能。将所有结果与基线正交频施加多路复用（OFDM）方案进行比较，该方案采用单个TAP最小均方根误差（MMSE）均衡器进行了比较。
This paper presents a linear complexity iterative rake detector for the recently proposed orthogonal time frequency space (OTFS) modulation scheme. The basic idea is to extract and coherently combine the received multipath components of the transmitted symbols in the delay-Doppler grid using maximal ratio combining (MRC) to improve the SNR of the combined signal. We reformulate the OTFS input-output relation in simple vector form by placing guard null symbols or zero padding (ZP) in the delay-Doppler grid and exploiting the resulting circulant property of the blocks of the channel matrix. Using this vector input-output relation we propose a low complexity iterative decision feedback equalizer (DFE) based on MRC. The performance and complexity of the proposed detector favorably compares with the state of the art message passing detector. An alternative time domain MRC based detector is also proposed for even faster detection. We further propose a Gauss-Seidel based over-relaxation parameter in the rake detector to improve the performance and the convergence speed of the iterative detection. We also show how the MRC detector can be combined with outer error-correcting codes to operate as a turbo DFE scheme to further improve the error performance. All results are compared with a baseline orthogonal frequency division multiplexing (OFDM) scheme employing a single tap minimum mean square error (MMSE) equalizer.
