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Zhimeng Zhong - IEEE Xplore Author Profile

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Intelligent reflecting surface (IRS) has been regarded as an emerging technology, which can significantly enhance the coverage and capacity of next-generation wireless networks. An accurate and easy-to-use channel model is essential to the deployment and evaluation of IRS-assisted communication systems. In this paper, we propose a 3D geometry-based channel model for the IRS-assisted multiple-input...Show More
Ultra-massive multiple-input multiple-output (MIMO) technology will bring unique channel characteristics that need to be fully explored through channel measurements and channel modeling. In this paper, single-user and multi-user channel measurements using ultra-massive MIMO antenna arrays with different configurations are conducted at 5.3 GHz band. The non-stationarity, spherical wavefront, channe...Show More
Recently, the concept of holographic multiple-input multiple-output (MIMO) is emerging as one of the promising technologies beyond massive MIMO. Many challenges need to be addressed to bring this novel idea into practice, including electromagnetic (EM)-compliant channel modeling and accurate performance evaluation. In this paper, an EM-compliant channel model is proposed for the holographic MIMO s...Show More
Extremely large-scale multiple-input multiple-output (XL-MIMO) system providing more degrees of freedom and beamforming gain, can effectively increase the capacity and coverage of wireless networks, which has become one of the key technologies for 6G. However, the near-field and non-stationary effects will appear as the array aperture expands. Therefore, existing channel models such as COST 2100 a...Show More
Extremely large antenna array (ELAA) is one of the most promising technologies in 5G-Advanced (5.5G), which is equipped with hundreds or even thousands of antennas at base station (BS), to meet the requirements of higher rate and spectral efficiency. To verify the characteristics of ELAA channel, including spatial non-stationary, near-field spherical wavefront effect and channel hardening, a measu...Show More
Nowadays, the demand for data traffic increases dramatically, which has posed significant challenge on the current infrastructures of cellular networks. To tackle the challenge, the massive multiple-input-multiple-output (MIMO) technology has been proposed, which can improve spectral efficiency greatly, and attract a lot of attentions in industry and academic. In spite of the great potential benef...Show More
In this paper, properties of the channel multipath are analyzed for the industrial environment, where there are full of metallic boxes, operating platforms, tubes and also the robotic arms which are used to operate manufacturing process instead of human. The analysis is implemented based on ray tracing simulation. For base station configuration, we use the multiple transmission and reception point...Show More
Reconfigurable intelligent surfaces (RISs) are 2-D metasurfaces, which can intelligently manipulate electromagnetic waves by low-cost near passive reflecting elements. RIS is viewed as a potential key technology for the sixth-generation (6G) wireless communication systems mainly due to its advantages in tuning wireless signals, thus smartly controlling propagation environments. In this article, we...Show More
Intelligent reflecting surface (IRS) can control the reflection of electromagnetic wave, so the deployment of IRS can adjust the channel conditions to enhance the coverage and throughput in the 5G evolution networks. Since the IRS is only capable of passively reflecting the received signals by adjusting the phase-shift, its path-loss modelling method is different from existing two-hop communicatio...Show More
The acquisition of downlink channel state information (CSI) at the base station is a prerequisite for various applications in frequency division duplex (FDD) massive multipleinput multiple-output (MIMO) systems. To obtain accurate CSI, conventional approaches employ downlink training and feedback with a considerable overhead. In this paper, we exploit the partial reciprocity between FDD uplink and...Show More
6G-7G Hz (U6G) is one promising frequency band and will be utilized in 5G evolution period, but this frequency band has been occupied by non-terrestrial network (NTN) networks in some countries. The interference assessment between NTN and 5G evolution services in U6G is one of key issues needed to be considered before the large-scale deployment of U6G band in 5G evolution. Therefore, the clutter l...Show More
Using compressed sensing and dictionary learning algorithms to reduce the number of pilot symbols is an effective way to improve the efficiency of channel estimation in frequency division duplexing (FDD) system. The typical predefined dictionaries used in compressed sensing may lead to energy leakage and hence cannot achieve satisfactory performance using sparse representation for current complex ...Show More
In a realistic fifth generation (5G) massive multiple-input multiple-output (MIMO) system, hardware constraints often pose challenges towards network design that are not sufficiently considered in the literature. In this work, we consider a time division duplex (TDD) network where user equipments (UEs) are equipped with N> 1 antennas for receiving in the downlink (DL) but only with a single antenn...Show More
One challenge for FDD massive MIMO communication system is how to obtain the downlink channel state information (CSI) at the base station. Except for traditional codebook feedback through uplink pilot transmission, some channel reciprocity properties can be utilized through uplink channel estimation and channel parameter estimation algorithms. In this paper, the uplink and downlink channel recipro...Show More
Artificial intelligence (AI) based downlink channel state information (CSI) prediction for frequency division duplexing (FDD) massive multiple-input multiple-output (MIMO) systems has attracted growing attention recently. However, existing works focus on the downlink CSI prediction for the users under a given environment and is hard to adapt to users in new environment especially when labeled data...Show More
One of the main differences between 5G and previous generations of cellular networks is that 5G supports not only mobile broadband enhancement, but also unprecedented reliability and very low latencies. This is beneficial to new applications in manufacturing scenario. In order to design a feasible wireless solution for manufacturing scenario, the particular characteristics of manufacturing environ...Show More
Coverage optimization is a key problem for wireless local area networks (WLANs) deployed for indoor access. Appropriate WLAN deployment should be planned based on the accurate channel fading characteristics. In this paper, we conduct a measurement campaign in two typical university classrooms on the large-scale channel fading of an access point (AP) at 2.4 and 5.8 GHz for both line-of-sight (LOS) ...Show More
Full-dimensional (FD) beamforming extends spatial multiplexing to the elevation domain and increases network capacity significantly. However, the beamforming employing a large number of active antenna elements consumes great power and also causes interference among sectors. The multipath spatial propagation characteristics determines the beamforming performance and should be investigated carefully...Show More
Radio channel modeling has been an important research topic, since the performance of any communication system depends on channel characteristics. So far, most existing clustering algorithms are conducted based on the multipath components (MPCs) extracted by using a high-resolution parameter estimation approach, e.g., SAGE or MUSIC, etc. However, most of the estimation approaches require prior inf...Show More
In this paper, by using a dual-band channel sounder equipped with omnidirectional antennas, we have measured and investigated the propagation parameters including path loss and shadowing at 1.79 and 4.9 GHz in the typical non-line-of-sight (NLOS) urban macrocell (UMa) scenario. Two different large-scale channel models, the alpha-beta-gamma (ABG) model and the close-in model with a frequency-weight...Show More
Channel modeling is an important research field in radio propagation, whereas clustering is one of key processes in the channel modeling. In this paper, edge detection algorithm is firstly applied for the clusters of signal in radio propagation channels, which can recognize the clusters with low computation cost. In the proposed algorithm, the clusters are detected based on the distribution of sig...Show More
Massive multiple-input multiple-output (MIMO) transmission is one of the key technologies utilized in the fifth generation (5G) wireless communication system. For the algorithm design and the performance evaluation of massive-MIMO, channel characterization based on real measurements is necessary. In this paper, we introduced a measurement campaign conducted in a Line-of-Sight (LoS) scenario of a s...Show More
In this paper, a novel target recognition based clustering algorithm is proposed for time-varying channels. Power angle spectrum (PAS) is extracted from measurement data by using Bartlett beamformer. Then the clusters in the PAS are separated from the background by using the proposed algorithm, where the amplitude distribution of the elements in the PAS is considered. Moreover, morphology operatio...Show More
In our previous work a scatterer-localization algorithm based on maximum-likelihood estimation was derived using spherical wavefront assumption. Individual Cramér-Rao Lower Bounds (CRLBs) for distance and azimuth estimation were presented. As a continuation, we now derive a joint CRLB for both distance and azimuth. The novelty lying in the joint CRLB is that the underlying Fisher Information Matri...Show More
In emerging heterogeneous networks, small-cell base stations deployed along urban streets can increase the network capacity for vehicular access significantly. To fully exploit the potential of full-dimensional multiple-input-multiple-output technologies, it is critical to understand the propagation characteristics of the small-cell vehicle-to-infrastructure (V2I) access channels. In this paper, a...Show More