Millimeter-wave (mmWave) radar has been widely applied in target detection. However, due to multipath and occlusion, radar often detects ghosts, especially in indoor environments. Existing solutions are mostly tailored to specific, simplified scenarios. To identify radar ghosts in diverse and complex indoor environments, we propose a data-driven approach. A thoughtful indoor radar ghost dataset is created with a multimodal data acquisition and automatic annotation system. And PairwiseNet, an end-to-end deep neural network adept at handling point-pair relationships within sparse point clouds, is proposed for radar ghost recognition. Multiframe accumulation is also implemented in PairwiseNet. To further enhance PairwiseNet, an additional network incorporating grid maps and U-Net is developed for constructing environmental maps from sequential point clouds. This network is trained through cross-modal distillation, with a depth camera as the teacher. Finally, a series of experiments validates the effectiveness of the proposed method in identifying indoor radar ghosts and autonomously constructing environmental maps. The classification accuracy on the test set reaches 96.0%, accurately identifying ghosts in the vast majority of cases.
{"title":"A Data-Driven Method for Indoor Radar Ghost Recognition With Environmental Mapping","authors":"Ruizhi Liu;Xinghui Song;Jiawei Qian;Shuai Hao;Yue Lin;Hongtao Xu","doi":"10.1109/TRS.2024.3456891","DOIUrl":"https://doi.org/10.1109/TRS.2024.3456891","url":null,"abstract":"Millimeter-wave (mmWave) radar has been widely applied in target detection. However, due to multipath and occlusion, radar often detects ghosts, especially in indoor environments. Existing solutions are mostly tailored to specific, simplified scenarios. To identify radar ghosts in diverse and complex indoor environments, we propose a data-driven approach. A thoughtful indoor radar ghost dataset is created with a multimodal data acquisition and automatic annotation system. And PairwiseNet, an end-to-end deep neural network adept at handling point-pair relationships within sparse point clouds, is proposed for radar ghost recognition. Multiframe accumulation is also implemented in PairwiseNet. To further enhance PairwiseNet, an additional network incorporating grid maps and U-Net is developed for constructing environmental maps from sequential point clouds. This network is trained through cross-modal distillation, with a depth camera as the teacher. Finally, a series of experiments validates the effectiveness of the proposed method in identifying indoor radar ghosts and autonomously constructing environmental maps. The classification accuracy on the test set reaches 96.0%, accurately identifying ghosts in the vast majority of cases.","PeriodicalId":100645,"journal":{"name":"IEEE Transactions on Radar Systems","volume":"2 ","pages":"910-923"},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1109/TRS.2024.3453708
Jonathan Bott;Muhammed Ali Yildirim;Benedikt Sievert;Florian Vogelsang;Tobias Welling;Philipp Konze;Daniel Erni;Andreas Rennings;Nils Pohl
This article introduces a 240-GHz multiple-input-multiple-output (MIMO) radar chipset, consisting of a 120-GHz voltage-controlled oscillator (VCO) monolithic microwave integrated circuit (MMIC) for generating the local oscillator (LO) signal and a 240-GHz transceiver (TRX) MMIC, doubling the frequency and containing one transmitter (Tx) and one receiver (Rx) channel. The Tx channel has a digital vector modulator (VM), allowing for phase adjustments. The 120-GHz VCO has a tuning range of 27.2 GHz (23.6%). The MIMO frequency-modulated continuous-wave (FMCW) system capabilities are demonstrated using a phase-locked loop (PLL)-based VCO stabilization generating wideband, 30-GHz FMCW chirps, which are radiated using a time-division multiplexing (TDM) technique. The MMICs feature a cascadable approach, enabling the scalability of the array size by placing multiple TRX MMICs close to each other using a daisy chain approach. Furthermore, a circular polarized on-chip antenna allows rotation of the MMICs, and the TRX MMIC can be connected to two adjacent edges of the VCO MMIC, creating a 2D array for detecting targets in 3-D space. In the demonstrator setup using eight MMICs, the eight Tx channels of the MMICs generate an equivalent isotropically radiated power (EIRP) of 0 dBm each, reflected from the target and received by eight Rx channels. Overall, the demonstrator system contains 64 virtual elements integrated on an array size of less than $10 times 10~text {mm}^{2}$