发表机构
School of Information and Electronics, Beijing Institute of Technology, China; Faculty of Electrical Engineering and Computer Science, Technical University of Berlin, Germany; the State Key Laboratory of Environment Characteristics and Effects for Near-space, Beijing Institute of Technology, China; School of Computer Science and Electronics Engineering, University of Essex, U.K（北京理工大学信息与电子学院; 柏林工业大学电气与计算机工程学院; 北京理工大学临近空间环境特性与效应国家重点实验室; 英国埃塞克斯大学计算机科学与电子工程学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
提出基于概率符号级预编码的AFDM传输框架，将处理负担转移至基站，接收端免信道估计与均衡，通过SOCP近似最小化错误概率，在保持性能的同时大幅降低接收端复杂度。
AI 中文摘要
仿射频分复用（AFDM）近年来因其对时频双选择性信道衰落的鲁棒性而受到广泛关注。然而，接收端的高计算复杂度对其实际部署构成了关键挑战。为克服这一问题，我们提出了一种基于概率符号级预编码（SLP）的AFDM传输框架，其中下行传输的处理负担从用户端转移到基站（BS），使得接收端无需信道估计或均衡即可直接进行符号检测。在所提出的框架中，基站利用上行信道状态信息（CSI），基于上下行信道互易性设计下行发射波形。特别地，我们创新性地引入了一种概率SLP技术，通过显式表征噪声扰动下符号检测错误的似然性。具体而言，优化发射符号以最小化接收符号落入错误判决区域的似然性，随后利用目标函数的单调性，将由此产生的错误概率最小化问题近似为二阶锥规划（SOCP）问题。仿真结果表明，所提出的基于概率SLP的方案在实现与传统AFDM接收机相当性能的同时，显著降低了接收端的计算复杂度。这些结果证明了所提方法的有效性和实际应用潜力。
英文摘要
Affine frequency division multiplexing (AFDM) has recently gained significant attention due to its robustness against time-frequency doubly selective channel fading. However, the high computational complexity at the receiver poses a critical challenge for practical deployment. To overcome this issue, we propose a probabilistic symbol-level precoding (SLP)-based AFDM transmission framework, in which the processing burden in downlink transmission is shifted from the user to the base station (BS), enabling direct symbol detection without channel estimation or equalization at the receiver. In the proposed framework, the BS exploits the uplink channel state information (CSI) to design the downlink transmit waveform based on uplink-downlink channel reciprocity. In particular, we innovatively introduce a probabilistic SLP technology by explicitly characterizing the likelihood of symbol detection errors under noise perturbations. Specifically, the transmitted symbols are optimized to minimize the likelihood that the received symbols fall into erroneous decision regions, where the resulting error-probability minimization problem is subsequently approximated as a second order cone programming (SOCP) problem by exploiting the monotonicity of the objective function. Simulation results show that the proposed probabilistic SLP-based scheme achieves performance comparable to that of conventional AFDM receivers, whilst enjoying significant reduction of computational complexity at the receiver end. These results demonstrate the effectiveness and practical potential of the proposed approach.
Comments6 pages,3 figures, conference
