基于码本的MIMO系统中预编码设计的有效CSI反馈
Codebook-Based Effective CSI Feedback for Precoding Design in MIMO Systems
- Skylo Technologies Europe Oy
- Centre for Wireless Communications, University of Oulu（奥卢大学无线通信中心）
- Nokia（诺基亚）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
针对多小区MIMO系统有限CSI反馈的预编码失配问题，提出ECSI反馈框架，通过UE合并后有效信道量化反馈，迭代优化预编码，实现平均总速率提升30%。
AI中文摘要：
研究了多小区系统中下行链路多用户多输入多输出（MIMO）预编码在有限信道状态信息（CSI）反馈下的性能。传统的基于码本的CSI反馈压缩了用户设备（UE）特定的物理信道，导致基站（BS）预编码器与干扰感知的UE合并器之间存在固有的不匹配。为解决这一限制，提出了一种有效CSI（ECSI）反馈框架，其中UE从预编码的下行导频计算其线性合并器，构建相应的合并后有效信道，并使用与传统方案相同的负载结构报告紧凑的量化表示。BS重建有效CSI，并通过空中信令迭代优化其预编码器，而无需增加额外的下行链路开销。推导了解析表达式，以表征在传统CSI和ECSI反馈下有效信道估计误差，明确捕捉了波束选择和秩截断的影响。仿真结果表明，在几次迭代内快速收敛，与传统基于CSI的预编码相比，平均总速率提升高达30%，在干扰受限条件下，每流速率的第10百分位增益达到100%。
英文摘要：
Downlink multi-user multiple-input multiple-output (MIMO) precoding with limited channel state information (CSI) feedback in multi-cell systems is studied. Conventional codebook-based CSI feedback compresses the UE-specific physical channels, which leaves an inherent mismatch between the base-station (BS) precoders and the interference-aware UE combiners. To address this limitation, an effective CSI (ECSI) feedback framework is proposed in which UEs compute their linear combiners from precoded downlink pilots, construct corresponding post-combining effective channels, and report compact quantized representations using the same payload structure as in conventional schemes. The BS reconstructs the effective CSI and iteratively refines its precoders through over-the-air signaling without incurring additional downlink overhead. Analytical expressions are derived to characterize the effective-channel estimation error under both conventional CSI and ECSI feedback, explicitly capturing the impact of beam selection and rank truncation. Simulations demonstrate fast convergence within a few iterations and up to 30\% average sum-rate improvement over conventional CSI-based precoding, with gains reaching 100\% at the 10th percentile of per-stream rates in interference-limited conditions.
