Pub Date : 2024-09-30DOI: 10.1109/OJCOMS.2024.3470844
Kaiqian Qu;Shuaishuai Guo;Nasir Saeed;Jia Ye
This paper explores the potential near-field beamforming (NFBF) in integrated sensing and communication (ISAC) systems with extremely large-scale arrays (XL-arrays). The large-scale antenna arrays increase the possibility of having communication users and targets of interest in the near field of the base station (BS). The paper first establishes the models of near-field spherical waves and far-field plane waves. With the models, we analyze the near-field beam focusing ability and the far-field beam steering ability by finding the gain-loss mathematical expression caused by the far-field steering vector mismatch in the near-field case. Subsequently, we analyzed the performance degradation caused by traditional far-field beamforming in the near field for both communication and sensing. We formulate the transceiver NFBF design problem as maximizing the sensing signal-to-interference-plus-noise ratio (SINR) while ensuring the required communication quality-of-service (QoS) and total power constraint. We decompose it into two subproblems and solve them using the generalized Rayleigh entropy theory and the Semi-Definite Relaxation (SDR) technique. Additionally, we prove the attainability of the optimal solution for SDR. Additionally, a low-complexity design scheme is proposed as an alternative to the SDR approach for obtaining transmit beamforming. The simulation results validate the effectiveness of the proposed NFBF scheme, demonstrating its capability to manage co-angle interference and enhance both communication and sensing performance.
{"title":"Near-Field Integrated Sensing and Communication: Performance Analysis and Beamforming Design","authors":"Kaiqian Qu;Shuaishuai Guo;Nasir Saeed;Jia Ye","doi":"10.1109/OJCOMS.2024.3470844","DOIUrl":"https://doi.org/10.1109/OJCOMS.2024.3470844","url":null,"abstract":"This paper explores the potential near-field beamforming (NFBF) in integrated sensing and communication (ISAC) systems with extremely large-scale arrays (XL-arrays). The large-scale antenna arrays increase the possibility of having communication users and targets of interest in the near field of the base station (BS). The paper first establishes the models of near-field spherical waves and far-field plane waves. With the models, we analyze the near-field beam focusing ability and the far-field beam steering ability by finding the gain-loss mathematical expression caused by the far-field steering vector mismatch in the near-field case. Subsequently, we analyzed the performance degradation caused by traditional far-field beamforming in the near field for both communication and sensing. We formulate the transceiver NFBF design problem as maximizing the sensing signal-to-interference-plus-noise ratio (SINR) while ensuring the required communication quality-of-service (QoS) and total power constraint. We decompose it into two subproblems and solve them using the generalized Rayleigh entropy theory and the Semi-Definite Relaxation (SDR) technique. Additionally, we prove the attainability of the optimal solution for SDR. Additionally, a low-complexity design scheme is proposed as an alternative to the SDR approach for obtaining transmit beamforming. The simulation results validate the effectiveness of the proposed NFBF scheme, demonstrating its capability to manage co-angle interference and enhance both communication and sensing performance.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"5 ","pages":"6353-6366"},"PeriodicalIF":6.3,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10700785","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142408930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-30DOI: 10.1109/OJCOMS.2024.3470689
Salem Titouni;Idris Messaoudene;Yassine Himeur;Massinissa Belazzoug;Boualem Hammache;Shadi Atalla;Wathiq Mansoor
Joint Communication Radar (JCR) systems have garnered significant attention due to their ability to simultaneously perform communication and radar sensing tasks. However, in challenging environments, JCR signals are vulnerable to multipath propagation, resulting in signal degradation, interference, and reduced system performance. This paper explores the challenges posed by multipath effects on JCR signals and proposes novel mitigation techniques to enhance their robustness and reliability. The suggested method involves employing a spectral transformation to enhance the JCR-emitted signal, resulting in a significant improvement in the overall effectiveness of JCR systems. Consequently, the numerical implementation of the JCR system integrated with the proposed technique leads to improved performance metrics, including Multipath Error Envelope (MEE), Root Mean Square Error (RMSE), and Standard Deviation (STD). By effectively mitigating the adverse impacts of multipath propagation, the proposed methodologies enhance the robustness and accuracy of JCR systems, leading to improved communication reliability and radar sensing capabilities. Notably, the proposed method achieved a minimal Root Mean Square Error (RMSE) of just 0.05, marking a substantial enhancement in performance compared to existing methods.
{"title":"An Efficient Spectral Approach for JCR Narrow Band Signals in Presence of Multipath and Noise","authors":"Salem Titouni;Idris Messaoudene;Yassine Himeur;Massinissa Belazzoug;Boualem Hammache;Shadi Atalla;Wathiq Mansoor","doi":"10.1109/OJCOMS.2024.3470689","DOIUrl":"https://doi.org/10.1109/OJCOMS.2024.3470689","url":null,"abstract":"Joint Communication Radar (JCR) systems have garnered significant attention due to their ability to simultaneously perform communication and radar sensing tasks. However, in challenging environments, JCR signals are vulnerable to multipath propagation, resulting in signal degradation, interference, and reduced system performance. This paper explores the challenges posed by multipath effects on JCR signals and proposes novel mitigation techniques to enhance their robustness and reliability. The suggested method involves employing a spectral transformation to enhance the JCR-emitted signal, resulting in a significant improvement in the overall effectiveness of JCR systems. Consequently, the numerical implementation of the JCR system integrated with the proposed technique leads to improved performance metrics, including Multipath Error Envelope (MEE), Root Mean Square Error (RMSE), and Standard Deviation (STD). By effectively mitigating the adverse impacts of multipath propagation, the proposed methodologies enhance the robustness and accuracy of JCR systems, leading to improved communication reliability and radar sensing capabilities. Notably, the proposed method achieved a minimal Root Mean Square Error (RMSE) of just 0.05, marking a substantial enhancement in performance compared to existing methods.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"5 ","pages":"6343-6352"},"PeriodicalIF":6.3,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10700591","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142408890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}