Yongyu Chang’s research while affiliated with Beijing University of Posts and Telecommunications and other places

... A different line of research has considered enhancing Channel Estimation Capacity from SRS information, e.g., by using deep learning tools, hence inherently improving the utilization of SRS sequences [36]. Also, multi-user grouping has been proposed as a strategy to minimize SRS resource requirements, by bringing together users based on channel state information [37], or channel correlation [38]. ...

Reference:

Traffic-Driven Sounding Reference Signal Resource Allocation in (Beyond) 5G Networks

... The role of small cells was investigated in [20] for optimizing downlink heterogeneous cellular networks under LOS and NLOS transmissions. Beside using a convolutional neural network (CNN) in a 3-D massive MIMO channel model, LOS detection [21,22] treated the problem as a binary hypothesis test. Based on time-space-frequency channel correlation, the system in [22] aimed to improve the new radio capacity and spectral efficiency of the 5G network. ...

Reference:

WiFi Access Points Line-of-Sight Detection for Indoor Positioning Using the Signal Round Trip Time

... To tackle the local minima problem of K-means, [128] proposed a genetic algorithm based on K-means (GAK-means) to perform user grouping for obtaining the optimal UAV deployment. The aforementioned solutions consider only non-overlapping user grouping, which may lead to resource waste [130]. Neto et al. [129] exploited fuzzy C-means algorithm to construct overlapped user groups in mmWave systems, while [25] [132] investigated clustering techniques for dynamic user grouping. ...

Reference:

Ai/Ml for Beyond 5g Systems: Concepts, Technology Enablers & Solutions

... There have been extensive studies that have appeared in the literature to present the potential gains of beamforming. Most of the reported work considers single cell scenarios [8,11,12]. Moreover, in the literature presenting larger-scale assessment, only physical layer metrics have been used to evaluate system performance [3,8,11,13]. ...

Reference:

Quantifying Network Level Improvement due to Beamforming on the Performance of Large-Scale Dense Urban IoT Networks

... The optimal number of the OPSs, that can be exploited, was fixed in [15], where half of the CI is dedicated for the channel training, while the other half is reserved for data transmission that is uplink/downlink data transmission. Standing on the spatial correlation of the channel vectors of the UEs, [16] analyzed the relationship between the users' signal-to-noise-plus-interference ratio (SINR) and the degree of correlation between the channel vectors; therefore, by properly separating the UEs of high correlation, it is possible to reach an enhanced SINR; however, perfect channel state information (CSI) is assumed, which is practically questionable. ...

Reference:

Pilot Contamination Suppression Based Coordination in Multi-cell Massive MIMO Systems

... There are many excellent research works [3][4][5][6][7] and reviews [8][9][10] in the literature dealing with the channel estimation. In recent years, the research on channel estimation mainly focuses on the following aspects: channel estimation based on deep learning, 11,12 channel estimation based on iteration, [13][14][15] and channel estimation based on compressive sensing (CS). ...

Reference:

The research on channel estimation and signal‐noise ratio estimation based on minimum error entropy kalman filter for single carrier frequency domain equalization system

... To perform it in the best possible way, the Rxs within one group should not be correlated or should be correlated as little as possible. Thus, spatial correlation is an important aspect of environment analysis [2] [3]. The other aspect of the conference use case is the propagation environment. ...

Reference:

Channel Impulse Response Measurements at mmWave Band in Office and Conference Rooms

... Furthermore, some literature considered channel correlations between users. For instance, correlation-based user grouping schemes were proposed to estimate inter-user interference and to improve the sum rate as in [14,15]. ...

Reference:

User Grouping and Power Allocation for Downlink NOMA-Based Quadrature Spatial Modulation

... The state-of-the-art analysis of the identification error rate is depicted in Fig. 8. The EFIM [9], MWT-CNN [11], CNN [12], and proposed CNN-HASSA methods are considered as the state-of-the-art methods to validate the identification error rate. The results confirm that compared with the existing methods, the proposed CNN-HASSA method offers less identification error rate with respect to all the sets described in Table 2. ...

Reference:

Machine learning-based intelligent localization technique for channel classification in massive MIMO

... To further reduce the complexity, a chordal distance method is proposed in [6] which performs selection in a way to maximize the channel matrix distance between the previously selected user and the new one. Its complexity order was regarded as the lowest one until maximum correlation value (MCV) method was not proposed in [7]. It utilizes correlation to measure the orthogonality degree between users and selects the one which has the highest value with already selected users. ...

Reference:

Correlation-based Overlapping User Grouping with Two-stage Precoding in IoT Oriented 5G MU-MIMO Systems