实时MIMO-OFDM SDR测试平台中基于轻量级CFR的调制自适应
Lightweight CFR-Based Modulation Adaptation in a Real-Time MIMO-OFDM SDR Testbed
- Eindhoven University of Technology（埃因霍温理工大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
该研究在实时MIMO-OFDM SDR测试平台中，采用轻量级CFR描述符替代传统SNR，通过DT、RF等分类器实现调制自适应，其性能优于仅用SNR的方案，且可在LabVIEW C Node中实时运行。
AI中文摘要：
传统链路自适应通常依赖信噪比（SNR）等标量链路质量指标，而更丰富的信道状态信息（CSI）可提升自适应性能，但需付出更高处理复杂度的代价。本文研究了实时多输入多输出正交频分复用（MIMO-OFDM）系统中用于调制选择的紧凑替代方案，该方案采用信道频率响应（CFR）幅度描述符。使用基于USRP的测试平台收集了87817个空中（OTA）样本的数据集，基站（BS）从接收的上行链路导频中提取CFR测量值。评估了决策树（DT）、随机森林（RF）和k近邻（KNN）分类器，使用BS侧SNR、CFR特征及其组合。仅SNR分类器的测试准确率为35%-42%，而仅CFR特征的DT、RF和KNN分类器分别达到73.6%、81.4%和80.0%。基于CFR的性能在接近10%的BLER可靠性阈值时得以保持，其中RF达到82.8%。将具有123个叶子节点的深度为7的DT进一步集成到LabVIEW C Node中以进行实时推理。结果表明，紧凑的BS侧CFR描述符比可用的标量BS侧SNR提供更具判别力的信息，同时仍适用于轻量级SDR实现。
英文摘要：
Conventional link adaptation typically relies on scalar link-quality indicators such as signal-to-noise ratio (SNR), while richer channel state information (CSI) can improve adaptation at the cost of higher processing complexity. This paper investigates a compact alternative for modulation selection in a real-time multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) system using channel frequency response (CFR) magnitude descriptors. A dataset of 87,817 over-the-air (OTA) samples is collected using a USRP-based testbed, with CFR measurements extracted at the base station (BS) from received uplink pilots. Decision tree (DT), random forest (RF), and k-nearest neighbours (KNN) classifiers are evaluated using BS-side SNR, CFR features, and their combination. SNR-only classifiers achieve 35%-42% test accuracy, whereas CFR-only features achieve 73.6%, 81.4%, and 80.0% for DT, RF, and KNN, respectively. CFR-based performance is maintained near the 10% BLER reliability thresholds, with RF reaching 82.8%. A depth-7 DT with 123 leaves is further integrated into the LabVIEW C Node for real-time inference. The results show that compact BS-side CFR descriptors provide more discriminative information than the available scalar BS-side SNR while remaining suitable for lightweight SDR implementation.
