scholarly journals Limited Feedback for 3D Massive MIMO under 3D-UMa and 3D-UMi Scenarios

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Zheng Hu ◽  
Shaoli Kang ◽  
Xin Su
Keyword(s):  
Massive Mimo ◽  
Limited Feedback ◽  
Base Station ◽  
Code Word ◽  
System Level ◽  
Word Index ◽  
Transmission Scheme ◽  
Rectangular Array ◽  
System Level Simulation ◽  
Lte Advanced

For three-dimensional (3D) massive MIMO utilizing the uniform rectangular array (URA) in the base station (BS), we propose a limited feedback transmission scheme in which the channel state information (CSI) feedback operations for horizontal domain and vertical domain are separate. Compared to the traditional feedback scheme, the scheme can reduce the feedback overhead, code word index search complexity, and storage requirement. Also, based on the zenith of departure angle (ZoD) distribution in 3D-Urban Macro Cell (3D-UMa) and 3D-Urban Micro Cell (3D-UMi) scenarios, we propose the angle quantization codebook for vertical domain, while the codebook of long term evolution-advanced (LTE-Advanced) is still adopted in horizontal domain to preserve compatibility with the LTE-Advanced. Based on the angle quantization codebook, the subsampled 3-bit DFT codebook is designed for vertical domain. The system-level simulation results reveal that, to compromise the feedback overhead and system performance, 2-bit codebook for 3D-UMa scenario and 3-bit codebook for 3D-UMi scenario can meet requirements in vertical domain. The feedback period for vertical domain can also be extended appropriately to reduce the feedback overhead.

scholarly journals Resource Allocation for Vertical Sectorization in LTE-Advanced Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Lei Song ◽  
Mugen Peng ◽  
Yan Li
Keyword(s):  
Resource Allocation ◽  
Interference Cancellation ◽  
Multiple Input Multiple Output ◽  
Three Dimensional ◽  
Base Station ◽  
System Level ◽  
System Level Simulation ◽  
Lte Advanced ◽  
Input Multiple Output ◽  
Resource Allocation Scheme

Massive multiple input multiple output (MIMO) technology has been discussed widely in the past few years. Three-dimensional MIMO (3D MIMO) can be seen as a promising technique to realize massive MIMO to enhance the performance of LTE-Advanced systems. Vertical sectorization can be introduced by means of adjusting the downtilt of transmitting antennas. Thus, the radiowave from a base station (BS) to a group of user equipments (UE) can be divided into two beams which point at two different areas within a cell. Intrasector interference is inevitable since the resources are overlapped. In this paper, the influence of intrasector interference is analyzed and an enhanced resource allocation scheme for vertical sectorization is proposed as a method of interference cancellation. Compared with the conventional 2D MIMO scenarios, cell average throughput of the whole system can be improved by vertical sectorization. System level simulation is performed to evaluate the performance of the proposed scheme. In addition, the impacts of downtilt parameters and intersite distance (ISD) on spectral efficiency and cell coverage are presented.

scholarly journals Dynamic Beamforming for Three-Dimensional MIMO Technique in LTE-Advanced Networks

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yan Li ◽  
Xiaodong Ji ◽  
Dong Liang ◽  
Yuan Li
Keyword(s):  
Massive Mimo ◽  
Mimo System ◽  
Three Dimensional ◽  
System Level ◽  
System Level Simulation ◽  
Cell Coverage ◽  
Mimo Networks ◽  
Lte Advanced ◽  
3D Mimo ◽  
Beamforming Algorithm

MIMO system with large number of antennas, referred to as large MIMO or massive MIMO, has drawn increased attention as they enable significant throughput and coverage improvement in LTE-Advanced networks. However, deploying huge number of antennas in both transmitters and receivers was a great challenge in the past few years. Three-dimensional MIMO (3D MIMO) is introduced as a promising technique in massive MIMO networks to enhance the cellular performance by deploying antenna elements in both horizontal and vertical dimensions. Radio propagation of user equipments (UE) is considered only in horizontal domain by applying 2D beamforming. In this paper, a dynamic beamforming algorithm is proposed where vertical domain of antenna is fully considered and beamforming vector can be obtained according to UEs’ horizontal and vertical directions. Compared with the conventional 2D beamforming algorithm, throughput of cell edge UEs and cell center UEs can be improved by the proposed algorithm. System level simulation is performed to evaluate the proposed algorithm. In addition, the impacts of downtilt and intersite distance (ISD) on spectral efficiency and cell coverage are explored.

scholarly journals Spatio-Radio Resource Management and Hybrid Beamforming for Limited Feedback Massive MIMO Systems

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1061 ◽  
Author(s):  
Hedi Khammari ◽  
Irfan Ahmed ◽  
Ghulam Bhatti ◽  
Masoud Alajmi
Keyword(s):  
Massive Mimo ◽  
Fourier Transforms ◽  
Mimo Systems ◽  
Limited Feedback ◽  
Base Station ◽  
Discrete Fourier Transforms ◽  
Beam Selection ◽  
Sum Rate ◽  
Hybrid Beamforming ◽  
Csi Feedback

In this paper, a joint spatio–radio frequency resource allocation and hybrid beamforming scheme for the massive multiple-input multiple-output (MIMO) systems is proposed. We consider limited feedback two-stage hybrid beamformimg for decomposing the precoding matrix at the base-station. To reduce the channel state information (CSI) feedback of massive MIMO, we utilize the channel covariance-based RF precoding and beam selection. This beam selection process minimizes the inter-group interference. The regularized block diagonalization can mitigate the inter-group interference, but requires substantial overhead feedback. We use channel covariance-based eigenmodes and discrete Fourier transforms (DFT) to reduce the feedback overhead and design a simplified analog precoder. The columns of the analog beamforming matrix are selected based on the users’ grouping performed by the K-mean unsupervised machine learning algorithm. The digital precoder is designed with joint optimization of intra-group user utility function. It has been shown that more than 50 % feedback overhead is reduced by the eigenmodes-based analog precoder design. The joint beams, users scheduling and limited feedbacK-based hybrid precoding increases the sum-rate by 27 . 6 % compared to the sum-rate of one-group case, and reduce the feedback overhead by 62 . 5 % compared to the full CSI feedback.

scholarly journals Downlink Power Allocation Strategy for Next-Generation Underwater Acoustic Communications Networks

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1297 ◽  
Author(s):  
Ahmad ◽  
Chang
Keyword(s):  
Power Allocation ◽  
Base Station ◽  
System Level ◽  
Underwater Acoustic Communications ◽  
Frequency Division ◽  
Next Generation ◽  
Acoustic Communications ◽  
Underwater Acoustic ◽  
Communications Networks ◽  
System Level Simulation

The increasing interest in next-generation underwater acoustic communications networks is due to vast investigation of oceans for oceanography, commercial operations in maritime areas, military surveillance, and more. A surface buoy or underwater base station controller (UBSC) communicates with either transceivers or underwater base stations (UBSs) via acoustic links. Transceivers further communicate with underwater sensor nodes using acoustic links. In this paper, we employ a downlink (DL) power allocation (PA) strategy using an orthogonal frequency-division multiple access (OFDMA) technique for underwater acoustic communications (UAC) networks. First, we present an approach to power offsets using three kinds of pilot spacing and apply the power boosting (PB) concept on orthogonal frequency-division multiplexing (OFDM) symbols for the UAC network. Secondly, we draw the block error rate (BLER) curves from link-level simulation (LLS) and analyze the signal-to-noise ratio (SNR) for both PA and non-PA strategies. Lastly, we adopt the best PB for system-level simulation (SLS) and compare the throughput and outage performance for PA and non-PA strategies. Hence, the simulation results confirm the effectiveness of the DL PA strategy for UAC networks.

scholarly journals Massive MIMO Adaptive Modulation and Coding Using Online Deep Learning

2021 ◽  
Author(s):  
Evgeny Bobrov ◽  
Dmitry Kropotov ◽  
Hao Lu ◽  
Danila Zaev
Keyword(s):  
Deep Learning ◽  
Massive Mimo ◽  
Learning Algorithm ◽  
Adaptive Modulation ◽  
System Level ◽  
Adaptive Modulation And Coding ◽  
Q Learning ◽  
Deep Learning Algorithm ◽  
System Level Simulation ◽  
Fully Connected

The paper describes an online deep learning algorithm for the adaptive modulation and coding in 5G Massive MIMO. The algorithm is based on a fully connected neural network, which is initially trained on the output of the traditional algorithm and then is incrementally retrained by the service feedback of its output. We show the advantage of our solution over the state-of-the-art Q-Learning approach. We provide system-level simulation results to support this conclusion in various scenarios with different channel characteristics and different user speeds. Compared with traditional OLLA our algorithm shows 10% to 20% improvement of user throughput in full buffer case. <br>

scholarly journals Intercell Interference Coordination through Limited Feedback

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Lingjia Liu ◽  
Jianzhong (Charlie) Zhang ◽  
Jae-Chon Yu ◽  
Juho Lee
Keyword(s):  
Wireless Communication ◽  
Communication Networks ◽  
Limited Feedback ◽  
Base Station ◽  
Base Stations ◽  
System Level ◽  
Wireless Communication Networks ◽  
Interference Coordination ◽  
Average Cell ◽  
Intercell Interference

We consider the applications of multicell transmission schemes to the downlink of future wireless communication networks. A multicell multiple-input multiple output-(MIMOs) based scheme with limited coordination among neighboring base stations (BSs) is proposed to effectively combat the intercell interference by taking advantage of the degreesoffreedom in the spatial domain. In this scheme, mobile users are required to feedback channel-related information to both serving base station and interfering base station. Furthermore, a chordal distance-based compression scheme is introduced to reduce the feedback overhead. The performance of the proposed scheme is investigated through theoretical analysis as well as system level simulations. Both results suggest that the so-called “intercell interference coordination through limited feedback” scheme is a very good candidate for improving the cell-edge user throughput as well as the average cell throughput of the future wireless communication networks.

Accelerating the 3GPP LTE System Level Simulation with NVidia CUDA

2011 ◽  
Vol 58-60 ◽  
pp. 1596-1601 ◽  
Author(s):  
Yuan Gao ◽  
Yin Sun ◽  
Chun Hui Zhou ◽  
Xin Su ◽  
Xi Bin Xu ◽  
...  
Keyword(s):  
Parallel Computing ◽  
Communication Systems ◽  
Reference Signal ◽  
System Level ◽  
Signal Design ◽  
Actual Performance ◽  
3Gpp Lte ◽  
System Level Simulation ◽  
Lte Advanced

With the rapid progress of standardization of 3GPP’s LTE (Long Term Evolution) and LTE-Advanced, many research attentions have been focused on the link level evaluations of the 3GPP LTE systems, so as to demonstrate the rationality of novel transmission techniques. Different from theoretical studies, incorporating novel transmission techniques in to the LTE communication systems may affect many parts of the systems, such as signaling process, reference signal design, feedback link design, and compatibility, etc. Link level studies might be too simple to evaluate the benefits of these novel techniques to the entire system. On the other hand, system level simulation concentrates on the performance of the entire network with tens of cells and hundreds to thousands of users. It is possible to illustrate the actual performance of a LTE system by simulations designed from a system standpoint. Since the simulated system is quite large, one can understand the speed of simulation is very important for system level simulation platform. In this paper, we propose a design of Matlab-based 3GPP LTE system level simulator, which makes use of parallel computing techniques supported by NVidia GeForce GTX 260 graphic card. Our simulation experience shows that the simulation time reduces by nearly 1/3 after employing parallel computing techniques.

scholarly journals Limited Feedback Precoding for Massive MIMO

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Xin Su ◽  
Jie Zeng ◽  
Jingyu Li ◽  
Liping Rong ◽  
Lili Liu ◽  
...  
Keyword(s):  
Massive Mimo ◽  
Large Scale ◽  
Multiple Input Multiple Output ◽  
Limited Feedback ◽  
Antenna System ◽  
Base Station ◽  
Array Antenna ◽  
Codebook Design ◽  
Input Multiple Output ◽  
Scenarios Simulation

The large-scale array antenna system with numerous low-power antennas deployed at the base station, also known as massive multiple-input multiple-output (MIMO), can provide a plethora of advantages over the classical array antenna system. Precoding is important to exploit massive MIMO performance, and codebook design is crucial due to the limited feedback channel. In this paper, we propose a new avenue of codebook design based on a Kronecker-type approximation of the array correlation structure for the uniform rectangular antenna array, which is preferable for the antenna deployment of massive MIMO. Although the feedback overhead is quite limited, the codebook design can provide an effective solution to support multiple users in different scenarios. Simulation results demonstrate that our proposed codebook outperforms the previously known codebooks remarkably.

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