Benefits of MIMO Systems in Practice: Increased Capacity, Reliability and Spectrum Efficiency

2006 ◽  
Author(s):  
Ana Katalinic ◽  
Robert Nagy ◽  
Radovan Zentner
Keyword(s):  
Mimo Systems ◽  
Spectrum Efficiency

scholarly journals BER and Spectrum Efficiency Analysis of Massive MIMO Systems for IoT Application

2019 ◽  
Vol 8 (4) ◽  
pp. 10587-10591
Keyword(s):  
Channel Estimation ◽  
Massive Mimo ◽  
Large Scale ◽  
Mimo Systems ◽  
Efficiency Analysis ◽  
Spatial Multiplexing ◽  
Spectrum Efficiency ◽  
Estimation Technique ◽  
Information Request ◽  
Factual Data

The fifth era of portable correspondence frameworks (5G) guarantees uncommon degrees of availability and nature of administration (QoS) to fulfill the unremitting development in the quantity of versatile savvy gadgets and the colossal increment in information request. One of the essential ways 5G organize innovation will be practiced is through arrange densification, to be specific expanding the quantity of radio wires per site and sending littler and littler cells. Gigantic MIMO, where MIMO represents numerous info various yield, is generally expected to be a key empowering agent of 5G. This innovation use a forceful spatial multiplexing, from utilizing countless transmitting/accepting reception apparatuses, to duplicate the limit of a remote channel. Such an appropriated engineering gives extra large scale decent variety, and the co-handling at numerous APs completely smothers the between cell obstruction. Contingent upon moderate/quick channel blurring conditions, a few creators recommended versatile LMS, RLS and NLMS based channel estimators, which either require factual data of the channel or are not proficient enough as far as execution or calculations. So as to conquer the above impacts, the work centers around the QR-RLS based channel estimation technique for Massive MIMO frameworks with various regulation plan.

scholarly journals A New Method in Pilot Reuse Factor Selection in Spectrum Efficient Massive MIMO Systems

2019 ◽  
Vol 25 (6) ◽  
pp. 70-77 ◽  
Author(s):  
Osman Dikmen ◽  
Selman Kulac
Keyword(s):  
Massive Mimo ◽  
Mimo Systems ◽  
Wave Structure ◽  
Base Station ◽  
Spectrum Efficiency ◽  
Zero Forcing ◽  
Millimetre Wave ◽  
Maximum Ratio Combining ◽  
A Cell ◽  
Definition Of

Spectrum efficiency studies of Massive MIMO systems have continued and still have not been fully explored in the literature. Therefore, the spectrum efficiency definition of a particular user in a cell in a Massive MIMO network is expressed in this paper. In addition, the uplink spectrum efficiency expressions for the Rayleigh fading are included. The Monte Carlo simulations are performed to verify these expressions. Due to the expectation of reaching to a thousand antennas together with the millimetre wave structure in the next years, in this study, it is contributed to the literature by explaining how to select the pilot reuse factor. The realization of this contribution is based on Zero Forcing (ZF) and Maximum Ratio Combining (MRC) schemes. The results of this study are useful for optimal design conditions, such as the number of antennas on the base station and pilot reuse factor selection for the next generation networks in order to obtain spectrum efficiency in Massive MIMO systems.

Joint Transmit Antenna Selection and User Selection in Cognitive Radio MIMO Systems

2014 ◽  
Vol 548-549 ◽  
pp. 1355-1358 ◽  
Author(s):  
Jie Li ◽  
Shuang Zhi Li ◽  
Xiao Min Mu ◽  
Jian Kang Zhang
Keyword(s):  
Cognitive Radio ◽  
System Performance ◽  
Mimo Systems ◽  
Antenna Selection ◽  
Spectrum Efficiency ◽  
Multiple Antenna ◽  
Hardware Complexity ◽  
Transmit Antenna Selection ◽  
Radio System ◽  
Set Up

Using multiple antennas in coexisting radio systems can cancel or control the co-channel interference and hence improves the overall spectrum efficiency. However, the hardware complexity and costs limit the usage of multiple-antenna technology. Antenna selection may reduce such costs while partly remaining the advantage of the multiple-antenna technology. In this paper, a fixed power cognitive radio system model jointly combined with antenna selection and users selection is set up. And the mathematical closed-form expressions of the channel capacity and bit error rate (BER) are obtained through mathematical derivation. Simulation verifies the correctness of theoretical results and shows that the system exists an optimal transmit power which optimizes the system performance. Furthermore, the influences of users number and antennas number on the system performance have been studied.

scholarly journals Orbit Angular Momentum MIMO with Mode Selection for UAV-Assisted A2G Networks

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2289
Author(s):  
Tao Hu ◽  
Yang Wang ◽  
Bo Ma ◽  
Jie Zhang
Keyword(s):  
Angular Momentum ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Channel Model ◽  
Mimo Systems ◽  
Mode Selection ◽  
Multiple Input Multiple Output ◽  
Base Stations ◽  
Spectrum Efficiency ◽  
Ms Scheme

As an emerging solution for line-of-sight (LOS) wireless communications, in air-to-ground (A2G) channels, the unmanned aerial vehicle (UAV), and allowing the dynamic and flexible network deployments enables the supplement or/and replacement of the terrestrial base stations (BSs). However, in conventional multiple-input-multiple-output (MIMO) systems, high-speed communications are significantly limited by channel crosstalks and spectrum scarcities. An orbit angular momentum (OAM) wireless network, allowing co-existence of multiple physical channels within the same frequency band, offers new degrees of freedom to address this dilemma. In this paper, we investigate the UAV-based A2G radio vortex wireless networks and study its channel model. Then we propose a branch and bound search-based mode selection (BBS-MS) scheme, which uses the spatial distribution characteristics of vortex beams to optimize the spectrum efficiency (SE). Theoretical derivations and numerical results demonstrate that our developed BBS-MS scheme can obtain the optimal performance, which outperforms conventional OAM-based MIMO systems. Also, it possesses a lower complexity compared with exhaustive searches.

scholarly journals Performance of Cross-Layer Design with Antenna Selection and Imperfect Feedback Information in MIMO Systems

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoyu Dang ◽  
Xiangbin Yu ◽  
Xiaomin Chen
Keyword(s):  
Mimo Systems ◽  
Antenna Selection ◽  
Mimo System ◽  
Spectrum Efficiency ◽  
Packet Error Rate ◽  
Cross Layer ◽  
Cross Layer Design ◽  
Feedback Information ◽  
Average Spectrum ◽  
Special Cases

By combining adaptive modulation and automatic repeat request, a cross-layer design (CLD) scheme for MIMO system with antenna selection (AS) and imperfect feedback is presented, and the corresponding performance is studied. Subject to a target packet loss rate and fixed power constraint, the variable switching thresholds of fading gain are derived. According to these results, and using mathematical manipulation, the average spectrum efficiency (SE) and packet error rate (PER) of the system are further derived. As a result, closed-form expressions of the average SE and PER are obtained, respectively. These expressions include the expressions under perfect channel state information as special cases and provide good performance evaluation for the system. Numerical results show that the proposed CLD scheme with antenna selection has higher SE than the existing CLD scheme with space-time block coding, and the CLD scheme with variable switching thresholds outperforms that with conventional-fixed switching thresholds.

scholarly journals On Matrix Completion-Based Channel Estimators for Massive MIMO Systems

Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1377
Author(s):  
Mingjun Ding ◽  
Xiaodong Yang ◽  
Rui Hu ◽  
Zhitao Xiao ◽  
Jun Tong ◽  
...  
Keyword(s):  
Computational Complexity ◽  
Massive Mimo ◽  
Communication Systems ◽  
Large Scale ◽  
Hybrid Methods ◽  
Mimo Systems ◽  
Low Cost ◽  
Matrix Completion ◽  
Spectrum Efficiency ◽  
Robust Solution

Large-scale symmetric arrays such as uniform linear arrays (ULA) have been widely used in wireless communications for improving spectrum efficiency and reliability. Channel state information (CSI) is critical for optimizing massive multiple-input multiple-output(MIMO)-based wireless communication systems. The acquisition of CSI for massive MIMO faces challenges such as training shortage and high computational complexity. For millimeter wave MIMO systems, the low-rankness of the channel can be utilized to address the challenge of training shortage. In this paper, we compared several channel estimation schemes based on matrix completion (MC) for symmetrical arrays. Performance and computational complexity are discussed and compared. By comparing the performance in different scenarios, we concluded that the generalized conditional gradient with alternating minimization (GCG-Alt) estimator provided a low-cost, robust solution, while the alternating direction method of multipliers (ADMM)-based hybrid methods achieved the best performance when the array response was perfectly known.

scholarly journals Channel Estimation for MIMO Systems

2022 ◽  
Vol 10 (1) ◽  
pp. 201-204
Author(s):  
Sonti Swapna
Keyword(s):  
Channel Estimation ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Least Square ◽  
Spectrum Efficiency ◽  
Mean Square ◽  
Multiple Input ◽  
Input Multiple Output

Abstract: A combination of multiple-input multiple-output (MIMO) systems and orthogonal frequency division multiplexing (OFDM) technologies can be employed in modern wireless communication systems to achieve high data rates and improved spectrum efficiency. For multiple input multiple output (MIMO) systems, this paper provides a Rayleigh fading channel estimation technique based on pilot carriers. The channel is estimated using traditional Least Square (LS) and Minimum Mean Square (MMSE) estimation techniques. The MIMO-OFDM system's performance is measured using the Bit Error Rate (BER) and Mean Square Error (MSE) levels. Keywords: MIMO, MMSE, Channel estimation, BER, OFDM

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