论文标题
混合RIS辅助毫米波OTFS系统的联合通道估计和数据检测
Joint Channel Estimation and Data Detection for Hybrid RIS aided Millimeter Wave OTFS Systems
论文作者
论文摘要
对于高移动性通信方案,最近出现的正交时间频率空间(OTFS)调制引入了一个新的延迟多普勒域信号空间,并且可以比传统的正交频差分线多路复用系统提供更好的通信性能。本文重点介绍了混合重新配置智能表面(HRIS)辅助毫米波(MMWAVE)OTFS系统的联合通道估计和数据检测(JCEDD)。首先,设计了新的传输结构。在设计结构的试验持续时间内,部分HRIS元素也会被激活。然后展示时间域通道模型。其次,研究了在时间域上的HRIS的接收信号模型,并且研究了延迟多普勒域上的基站。第三,通过利用在HRIS上获得的通道参数,提出了HRIS波束形成的设计策略。对于OTFS传输,我们在延迟多普勒域上提出了JCEDD方案。在此方案中,消息传递(MP)算法旨在同时获得等效的通道增益和数据符号。另一方面,通道参数,即多普勒偏移,通道稀疏性和通道方差,通过预期最大化(EM)算法进行更新。通过迭代执行MP和EM算法,可以准确获取通道和未知数据符号。最后,提供仿真结果以验证我们提出的JCEDD方案的有效性。
For high mobility communication scenario, the recently emerged orthogonal time frequency space (OTFS) modulation introduces a new delay-Doppler domain signal space, and can provide better communication performance than traditional orthogonal frequency division multiplexing system. This article focuses on the joint channel estimation and data detection (JCEDD) for hybrid reconfigurable intelligent surface (HRIS) aided millimeter wave (mmWave) OTFS systems. Firstly, a new transmission structure is designed. Within the pilot durations of the designed structure, partial HRIS elements are alternatively activated. The time domain channel model is then exhibited. Secondly, the received signal model for both the HRIS over time domain and the base station over delay-Doppler domain are studied. Thirdly, by utilizing channel parameters acquired at the HRIS, an HRIS beamforming design strategy is proposed. For the OTFS transmission, we propose a JCEDD scheme over delay-Doppler domain. In this scheme, message passing (MP) algorithm is designed to simultaneously obtain the equivalent channel gain and the data symbols. On the other hand, the channel parameters, i.e., the Doppler shift, the channel sparsity, and the channel variance, are updated through expectation-maximization (EM) algorithm. By iteratively executing the MP and EM algorithm, both the channel and the unknown data symbols can be accurately acquired. Finally, simulation results are provided to validate the effectiveness of our proposed JCEDD scheme.