In this paper, we investigate the performance of the cross-domain iterative detection (CDID) framework with orthogonal time frequency space (OTFS) modulation, where two distinct CDID algorithms are presented. The proposed schemes estimate/detect the information symbols iteratively across the frequency domain and the delay-Doppler (DD) domain via passing either the a posteriori or extrinsic information. Building upon this framework, we investigate the error performance by considering the bias evolution and state evolution. Furthermore, we discuss their error performance in convergence and the DD domain error state lower bounds in each iteration. Specifically, we demonstrate that in convergence, the ultimate error performance of the CDID passing the a posteriori information can be characterized by two potential convergence points. In contrast, the ultimate error performance of the CDID passing the extrinsic information has only one convergence point, which, interestingly, aligns with the matched filter bound. Our numerical results confirm our analytical findings and unveil the promising error performance achieved by the proposed designs.

翻译：本文研究了正交时频空间(OTFS)调制下跨域迭代检测(CDID)框架的性能，提出了两种不同的CDID算法。所提方案通过传递后验信息或外生信息，在频域和时延多普勒(DD)域之间迭代估计/检测信息符号。基于此框架，我们通过考虑偏差演化和状态演化来研究其误码性能。此外，我们讨论了算法收敛时的误码性能以及每次迭代中DD域误差状态的下界。具体而言，我们证明在收敛状态下，传递后验信息的CDID的最终误码性能可由两个潜在收敛点表征；而传递外生信息的CDID的最终误码性能仅有一个收敛点，且该点与匹配滤波器界重合。数值结果验证了理论分析，并揭示了所提设计具有优异的误码性能。