scholarly journals Measurement-Based Spatial Correlation and Capacity of Indoor Distributed MIMO System

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Yan Zhang ◽  
Limin Xiao ◽  
Shidong Zhou ◽  
Jing Wang
Keyword(s):  
Spatial Correlation ◽  
Antenna Selection ◽  
Mimo System ◽  
Correlation Coefficients ◽  
Small Scale ◽  
Channel Measurements ◽  
Wireless Access Networks ◽  
Indoor Scenarios ◽  
Transmitting Antenna ◽  
The Impact

Distributed MIMO (D-MIMO) system is one of the candidates for future wireless access networks. In this study, the spatial correlation and capacity in indoor D-MIMO system are presented. All results are from the actual channel measurements in typical indoor scenarios, including office and corridor. Based on measured data, spatial correlation coefficients between distributed transmitting antennas are analyzed. Although the literature about D-MIMO system assumes the small scale fading between distributed antennas is independent, we find that spatial correlation may still exist in specific propagation scenario. This correlation can also degrade the performance of D-MIMO system. To mitigate the impact of spatial correlation, one efficient method is to use transmitting antenna selection technique.

scholarly journals Ray-Based Statistical Propagation Modeling for Indoor Corridor Scenarios at 15 GHz

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Qi Wang ◽  
Bo Ai ◽  
Ke Guan ◽  
David W. Matolak ◽  
Ruisi He ◽  
...  
Keyword(s):  
Communication Systems ◽  
Channel Model ◽  
Deterministic Model ◽  
Path Loss ◽  
Propagation Characteristic ◽  
Directional Antennas ◽  
Small Scale ◽  
Delay Spread ◽  
Channel Measurements ◽  
The Impact

According to the demands for fifth-generation (5G) communication systems, high frequency bands (above 6 GHz) need to be adopted to provide additional spectrum. This paper investigates the characteristics of indoor corridor channels at 15 GHz. Channel measurements with a vector network analyzer in two corridors were conducted. Based on a ray-optical approach, a deterministic channel model covering both antenna and propagation characteristic is presented. The channel model is evaluated by comparing simulated results of received power and root mean square delay spread with the corresponding measurements. By removing the impact of directional antennas from the transmitter and receiver, a path loss model as well as small-scale fading properties for typical corridors is presented based on the generated samples from the deterministic model. Results show that the standard deviation of path loss variation is related to the Tx height, and placing the Tx closer to the ceiling leads to a smaller fluctuation of path loss.

scholarly journals A Novel Joint Transmitting and Receiving Antenna Selection for Spatial Multiplexing Systems

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mingjie Zhuang ◽  
Haitao Li ◽  
Yisong Lin
Keyword(s):  
Computational Complexity ◽  
Optimal Algorithm ◽  
Antenna Selection ◽  
Mimo System ◽  
Antenna System ◽  
Spatial Multiplexing ◽  
Mimo Channel ◽  
Maximum Capacity ◽  
Receiving Antenna ◽  
Transmitting Antenna

AbstractHow to reduce the hardware cost and high power consumption of RF link of communication device is the key problem to be solved for multi-transmitting antenna and multi-receiving antenna system (MIMO). Always choose the best antennas connection a limited number of RF circuits, which is called antenna selection technology (AS), are a perfect solution to the problem, Assuming that the spatial range of the antenna meets the requirements of signal multiplexing and based on the maximum capacity criterion of the selected MIMO system, the manuscript proposes a low computational complexity (CC) and high performance joint transmitting and receiving antenna selection technique (JTRAS). Starting from the traditional capacity formula and the full matrix of MIMO channel, we utilize a simplified channel capacity expression through repeatedly iterating to delete a row and a column of the equivalent decrement channel matrix, which is to remove a pair of transmitting and receiving antennas. Based on the decreasing JTRAS (DJTRAS) algorithm, the capacity results of simulating calculation indicate that its median capacity overtakes other ones, such as optimum selection (OS), AS based on Frobenius 2 norm (NBS), and concise joint AS criterion (CJAS) etc., and the novel DJTRAS scheme can significantly reduce computational complexity (CC) compared to the exhaustive search method with maximum capacity, which defined as optimal algorithm in the curve graphs. This new technology of the AS is particularly suited to large number of selected antennas, such as Lt ≥ NT/2,Lr ≥ NR/2.

scholarly journals An Analytical Study of the Impact of Arbitrary Receive Antenna Correlation in TAS/MRC

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Juan P. Peña-Martín ◽  
Juan M. Romero-Jerez
Keyword(s):  
Closed Form ◽  
Channel Capacity ◽  
Antenna Selection ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Maximal Ratio Combining ◽  
Closed Form Expression ◽  
Transmit Antenna Selection ◽  
Input Multiple Output ◽  
The Impact

Novel closed-form expressions are derived for the performance analysis of a multiple-input multiple-output (MIMO) system in Rayleigh fading using transmit antenna selection (TAS) at the transmitter and maximal ratio combining (MRC) at the receiver. Receive antennas are assumed to be arbitrarily correlated, as no restriction is imposed on the correlation matrix. General exact and asymptotic expressions to evaluate the bit error rate (BER) of different modulation schemes are presented for uncoded transmission, and a closed-form expression is presented for the channel capacity. It is demonstrated that channel capacity may improve due to correlation at the receive antennas if the transmit array size is large enough as a result of a higher signal variability and the antenna selection performed at the transmitter. Monte Carlo simulations have been carried out to validate the analysis, showing an excellent agreement with the theoretical results.

scholarly journals On the Performance of the Time Reversal SM-MIMO-UWB System on Correlated Channels

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Hieu Nguyen ◽  
Van Duc Nguyen ◽  
Trung Kien Nguyen ◽  
Kiattisak Maichalernnukul ◽  
Feng Zheng ◽  
...  
Keyword(s):  
Spatial Correlation ◽  
Time Reversal ◽  
Channel Model ◽  
Line Of Sight ◽  
Channel Measurements ◽  
Virtual Mimo ◽  
Correlated Channels ◽  
Multiple Transmit ◽  
Correlated Channel ◽  
The Impact

The impact of spatial correlation on the multi-input multi-output ultrawide band (MIMO-UWB) system using the time reversal (TR) technique is investigated. Thanks to TR, several data streams can be transmitted by using only one antenna in a system named virtual MIMO-TRUWB. Since the virtual MIMO-TR-UWB system is not affected by the transmit correlation, under the condition of the high spatial correlation, it outperforms the true MIMO-UWB system with multiple transmit antennas. The channel measurements are performed in short-range indoor environment, both line-of-sight and non-line-of-sight to verify the adopted correlated channel model.

scholarly journals Secrecy Capacity of Time Reversal Beamforming for Multi-User MIMO System under Spatial Correlation

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Bingyan He ◽  
Tao Sun ◽  
Chuanmu Li ◽  
Xingwang Huang
Keyword(s):  
Spatial Correlation ◽  
Time Reversal ◽  
Performance Metrics ◽  
Channel Model ◽  
Mimo System ◽  
Cost Effective ◽  
Significant Loss ◽  
Secrecy Capacity ◽  
Sum Rate ◽  
The Impact

In this paper, for strengthening the security of wireless transmission system, the time reversal (TR) beamforming method is proposed for the downlink of multi-user MIMO system with multiple users who potentially act as eavesdroppers. We develop a multi-input, single-output, multi-eavesdropper (MISOME) wiretap channel model in which Rayleigh fading and spatial correlation are taken into account. Using the proposed model, we further analyze the confidentiality provided by TR beamforming and we use achievable secrecy rates as our performance metrics. In particular, we derive novel closed-formed expressions for the average secrecy-SINR and the mean secrecy sum-rate in order to characterize the influences of propagation conditions on network secrecy metrics. These expressions provide deeper insights into the impact of network interference on communication confidentiality. We find that TR beamforming can deliver the maximum secrecy capacity potential in uncorrelated Rayleigh channels and achieve perfect confidential communication without any extra secrecy cost. On the other hand, even weak inter-user correlation may cause a significant loss of achievable secrecy sum-rate and therefore result in high secrecy cost. But benefiting more from larger signal bandwidth and rich-scattering environment, the TR beamforming technique is still an attractive and cost-effective solution for low-power indoor applications.

scholarly journals Spatial Correlation Based Transmit Antenna Selection Assisted Fully Generalized Spatial Modulation for Peer-to-Peer Communications

2021 ◽  
Author(s):  
Vinoth Babu Kumaravelu ◽  
Gudla Vishnu Vardhan ◽  
Asha S ◽  
Prakasam P ◽  
Arthi Murugadass ◽  
...  
Keyword(s):  
Spatial Correlation ◽  
Mimo Systems ◽  
Antenna Selection ◽  
Peer To Peer ◽  
Spatial Modulation ◽  
Small Cells ◽  
Small Scale ◽  
Next Generation ◽  
Transmit Antenna Selection ◽  
Millimetre Wave

Abstract The next generation technologies like device-to-device ( D2D ) and small cells employ small scale multiple input multiple output ( MIMO ) systems for peer-to-peer ( P2P ) communications. Due to higher spectral and energy efficiencies , spatial modulation (SM) has become one of the dominant next generation technologies. To maximize spectral efficiency and user experience, high rate SM variants like fully generalized spatial modulation ( FGSM ) can be employed for P2P applications. Due to insufficient spacing between antenna elements of devices, access points (AP), millimetre wave ( mmWave ) and sub- THz bands of operations, the performance of SM variants are hindered in P2P scenarios. The average bit error rate ( ABER ) performance of FGSM is severely degraded by atleast 13 dB under spatially correlated channel conditions. To enhance the performance of FGSM , three different transmit antenna selection ( TAS ) schemes are utilized, which eliminate transmit antennas with maximum spatial correlation. First TAS scheme performs antenna selection based on spatial correlation angle alone, whereas other two schemes use channel capacity in addition to spatial correlation angle. Through extensive Monte Carlo simulations, it has been proved that TAS based on spatial correlation ( TAS -SC- FGSM ) scheme offers a performance gain of at least 8 dB over conventional FGSM without antenna selection ( FGSM - NTAS ). TAS -SC- FGSM also outperforms other two hybrid TAS schemes at the cost of higher computational complexity.

scholarly journals Tripolarizated MIMO: Experimental Analysis and Modeling of Channel Properties in Both Indoor and Outdoor Scenarios

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Pan Tang ◽  
Jianhua Zhang ◽  
Zuolong Ying ◽  
Yuxiang Zhang ◽  
Lei Tian ◽  
...  
Keyword(s):  
Communication Systems ◽  
Large Scale ◽  
Mimo Systems ◽  
Mimo System ◽  
High Capacity ◽  
Small Scale ◽  
Delay Spread ◽  
Channel Measurements ◽  
Channel Properties ◽  
Indoor And Outdoor

The tripolarized MIMO system can provide one more degree of freedom and have a more compacted size over a dual-polarized MIMO system, which is attractive for high-capacity wireless communication systems. In this paper, we analyze and model channel properties for tripolarized MIMO systems based on experimental channel measurements in typical indoor and outdoor scenarios. Firstly, channel measurement campaigns in the laboratory and the Urban Micro (UMi) scenarios on sub-6 GHz bands are presented. Then, based on measured data, path loss, delay spread (DS), and cross-polarization discrimination (XPD) for 9 polarization combinations are analyzed and modeled in a statistical way. Statistical results of these channel properties are also given. It is observed that channel properties of both large-scale fading and small-scale fading depend strongly on the polarization direction. Furthermore, we evaluate the performance of tripolarized MIMO systems by analyzing the Demmel condition number and channel capacity gain (CG). For both the indoor and the outdoor scenarios, it is found that colocated tripolarized antenna can bring a nearly threefold CG with respect to the unipolarized one. These results can give good insights into the design and evaluation of tripolarized MIMO systems.

Can Values of Honesty, Hard Work, Loyalty and Discipline Predict Entrepreneurial Orientation of Muslim Owner Managers?

2015 ◽  
Vol 3 (1) ◽  
pp. 31 ◽  
Author(s):  
Rohani Mohd ◽  
Badrul Hisham Kamaruddin ◽  
Khulida Kirana Yahya ◽  
Elias Sanidas
Keyword(s):  
Entrepreneurial Orientation ◽  
Two Dimensions ◽  
Hard Work ◽  
Small Scale ◽  
Sampling Frame ◽  
Policy Makers ◽  
Learning Institutions ◽  
Innovative Orientation ◽  
The Impact ◽  
True Values

The purpose of the present study is twofold: first, to investigate the true values of Muslim owner managers; second, to examine the impact of these values on entrepreneurial orientations of Muslim small-scale entrepreneurs. 850 Muslim owner managers were selected randomly using the sampling frame provided by MajlisAmanah Rakyat Malaysia (MARA). 162 completed questionnaires were collected and analyzed. For this paper only two dimensions of entrepreneurial orientations were analyzed: proactive orientation and innovative orientation. Interestingly, the findings revealed that Muslim businessmen/women are honest, loyal, disciplined and hard working. Loyalty and honesty are positively related to proactive orientation, while discipline and hard-work are positively related to innovative orientation. The findings provide implications for existing relevant theories, policy makers, practitioners and learning institutions. 

scholarly journals Land Subsidence Estimation for Aquifer Drainage Induced by Underground Mining

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4658
Author(s):  
Artur Guzy ◽  
Wojciech T. Witkowski
Keyword(s):  
Environmental Impact ◽  
Land Subsidence ◽  
Field Data ◽  
Underground Mining ◽  
Small Scale ◽  
Aquifer System ◽  
Maximum Value ◽  
The Impact ◽  
Method Model ◽  
Impact Of Mining

Land subsidence caused by groundwater withdrawal induced by mining is a relatively unknown phenomenon. This is primarily due to the small scale of such movements compared to the land subsidence caused by deposit extraction. Nonetheless, the environmental impact of drainage-related land subsidence remains underestimated. The research was carried out in the “Bogdanka” coal mine in Poland. First, the historical impact of mining on land subsidence and groundwater head changes was investigated. The outcomes of these studies were used to construct the influence method model. With field data, our model was successfully calibrated and validated. Finally, it was used for land subsidence estimation for 2030. As per the findings, the field of mining exploitation has the greatest land subsidence. In 2014, the maximum value of the phenomenon was 0.313 cm. However, this value will reach 0.364 m by 2030. The spatial extent of land subsidence caused by mining-induced drainage extends up to 20 km beyond the mining area’s boundaries. The presented model provided land subsidence patterns without the need for a complex numerical subsidence model. As a result, the method presented can be effectively used for land subsidence regulation plans considering the impact of mining on the aquifer system.

Sign in / Sign up

Export Citation Format

Share Document