scholarly journals Gallager Exponent Analysis of Coherent MIMO FSO Systems over Gamma-Gamma Turbulence Channels

Entropy ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1245
Author(s):  
Maoke Miao ◽  
Xiaofeng Li
Keyword(s):  
Fading Channels ◽  
Upper Bound ◽  
Communication Systems ◽  
Large Scale ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Block Code ◽  
Ergodic Capacity ◽  
High Signal ◽  
Free Space Optical

This paper studies the Gallager’s exponent for coherent multiple-input multiple-output (MIMO) free space optical (FSO) communication systems over gamma–gamma turbulence channels. We assume that the perfect channel state information (CSI) is known at the receiver, while the transmitter has no CSI and equal power is allocated to all of the transmit apertures. Through the use of Hadamard inequality, the upper bound of the random coding exponent, the ergodic capacity and the expurgated exponent are derived over gamma–gamma fading channels. In the high signal-to-noise ratio (SNR) regime, simpler closed-form upper bound expressions are presented to obtain further insights into the effects of the system parameters. In particular, we found that the effects of small and large-scale fading are decoupled for the ergodic capacity upper bound in the high SNR regime. Finally, a detailed analysis of Gallager’s exponents for space-time block code (STBC) MIMO systems is discussed. Monte Carlo simulation results are provided to verify the tightness of the proposed bounds.

Analysis of Stacked Alamouti Coding in Wireless Communication

2013 ◽  
Vol 380-384 ◽  
pp. 3505-3508
Author(s):  
Yi Peng Li ◽  
Hao Yang
Keyword(s):  
Wireless Communication ◽  
Upper Bound ◽  
Communication Systems ◽  
Signal To Noise Ratio ◽  
Ergodic Capacity ◽  
Wireless Communication Systems ◽  
High Signal ◽  
Signal To Noise ◽  
Alamouti Scheme ◽  
Alamouti Coding

Stacked Alamouti coding in MIMO wireless communication systems was analyzed through equivalent channel.We derive an upper bound on the portion of the ergodic capacity that the stacked Alamouti scheme can achieve, which is dependent on the ratio of number of transmit antennas to that of receive antennas in the high signal-to-noise ratio regime. As a conclusion, it is shown that the stacked Alamouti scheme can approach the channel capacity as long as the number of transmit antennas is no less than two times that of receive antennas.

scholarly journals On the Probability of Erasure for MIMO-OFDM

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Kasturi Vasudevan ◽  
A. Phani Kumar Reddy ◽  
Gyanesh Kumar Pathak ◽  
Shivani Singh
Keyword(s):  
Fading Channels ◽  
Communication Systems ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Spatial Multiplexing ◽  
Main Requirement ◽  
Valid Signal ◽  
Input Multiple Output ◽  
Mimo Ofdm ◽  
Wireless Standards

Detecting the presence of a valid signal is an important task of a telecommunication receiver. When the receiver is unable to detect the presence of a valid signal, due to noise and fading, it is referred to as an erasure. This work deals with the probability of erasure computation for orthogonal frequency division multiplexed (OFDM) signals used by multiple input multiple output (MIMO) systems. The theoretical results are validated by computer simulations. OFDM is widely used in present day wireless communication systems due to its ability to mitigate intersymbol interference (ISI) caused by frequency selective fading channels. MIMO systems offer the advantage of spatial multiplexing, resulting in increased bit-rate, which is the main requirement of the recent wireless standards like 5G and beyond.

scholarly journals Evaluation of Development Level and Technical Contribution of Recent Technologies Adopted to Meet the Challenges of 5G Wireless Cellular Networks

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 635
Author(s):  
Saleh Albadran
Keyword(s):  
Cellular Networks ◽  
Spectral Efficiency ◽  
Communication Systems ◽  
Large Scale ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Radio Link ◽  
Media Industry ◽  
Wireless Cellular Networks ◽  
Development Level

The evolution of the global wireless market is accompanied by an increased need in terms of speed and number of users, lower latency, better coverage, better spectral efficiency and quality of service, etc. To meet these needs, 5G has recently been introduced as an effective solution which targets, via the large scale deployment of symmetric antennas, a wide variety of sectors such as energy, health, media, industry, transport and especially wireless cellular networks which are among the most important pillars of modern societies. Multiple Input, Multiple Output (MIMO) systems, which have been extended to “Massive MIMO” mode and which consist of increasing the number of radiating elements involved in the transmission and reception of the radio link, are a very promising solution for improving the spectral efficiency of wireless communication systems (WCSs). Motivated by the aforementioned developments, the present paper investigates the increased capacity of MIMO systems to improve transmission in WCSs using 5G. It carefully focuses on the evaluation of the development level and technical contribution of MIMO systems and millimeter wave (mmWave) bands in 5G wireless cellular networks (WCNs) and gives important recommendations.

scholarly journals Studying and Modeling the Performance of the TCM-STBC Systems in the Rayleigh Channel

2021 ◽  
Vol 1 ◽  
pp. 1-7
Author(s):  
Mohammed Sofiane Bendelhoum ◽  
Mohamed Rida Lahcene ◽  
Fayssal Menezla ◽  
Abderraouf Elarbi
Keyword(s):  
Communication Systems ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Block Code ◽  
Space Time ◽  
Performance Comparison ◽  
Coded Modulation ◽  
Rayleigh Channel ◽  
Input Multiple Output ◽  
Matrix Codes

Multiple-input multiple-output (MIMO) systems will play an important role in future generations of wireless networks. Space-time block code (STBC) and space-time trellis code (STTC) are two techniques that may be used in multi-antenna radio systems. This paper aims, most importantly, to study the performance of STBC systems at different vallues of such parameters as spectral efficiency, matrix codes and constellations. A performance comparison between STBC and STTC schemes is performed. In order to show the efficiency of the system’s ability to communicate with uncoded and coded transmission structures over AWGN and Rayleigh channels, the trellis-coded modulation (TCM) is introduced. The results obtained show that the proposed TCM-STBC system model, using one and two receiving antennas, improves the performance of Rayleigh channel communication systems at 9.5 dB and 11.5 dB for a BER of 10−5

scholarly journals Beamforming Using Exact Evaluation of Leakage and Ergodic Capacity of MU-MIMO System

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6792
Author(s):  
Ahmad Kamal Hassan ◽  
Muhammad Moinuddin
Keyword(s):  
Closed Form ◽  
Fading Channels ◽  
Quadratic Forms ◽  
Mimo Systems ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Ergodic Capacity ◽  
Leakage Rate ◽  
Telecommunication Networks ◽  
Indefinite Quadratic

Closed-form evaluation of key performance indicators (KPIs) of telecommunication networks help perform mathematical analysis under several network configurations. This paper deals with a recent mathematical approach of indefinite quadratic forms to propose simple albeit exact closed-form expressions of the expectation of two significant logarithmic functions. These functions formulate KPIs which include the ergodic capacity and leakage rate of multi-user multiple-input multiple-output (MU-MIMO) systems in Rayleigh fading channels. Our closed-form expressions are generic in nature and they characterize several network configurations under statistical channel state information availability. As a demonstrative example of the proposed characterization, the derived expressions are used in the statistical transmit beamformer design in a broadcast MU-MIMO system to portray promising diversity gains using standalone or joint maximization techniques of the ergodic capacity and leakage rate. The results presented are validated by Monte Carlo simulations.

scholarly journals Optimization of Transmit Powers fof Cooperative Communication Systerms Over Tayleigh Fading Channels

2012 ◽  
Author(s):  
LE Quoc Cuong
Keyword(s):  
Power Allocation ◽  
Fading Channels ◽  
Cooperative Communication ◽  
Communication Systems ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Optimal Power Allocation ◽  
Amplify And Forward ◽  
Relay Nodes ◽  
Optimal Power

The paper sudies the transmit power optimization for cooperative multiple-input multiple-output (MIMO) systems using amplify-and-forward (AF) technique. The suty examines and evaluates the system in which the communication between the sourece and the multi-antenna equipped destiation is helped by multi relay nodes. To further improve the perfornamce of the system, the optimal power allocation between the source and relay(s) is also considered. In terms of outage probalblity, numerical results show that cooperative communication systems using optimal power allocation profile outperform those with uniform power allocaion profile.

scholarly journals Performance of MIMO Systems Over Weibull Fading Channel using Maximal Ratio Combining

2019 ◽  
Vol 9 (2) ◽  
pp. 4410-4415
Keyword(s):  
Communication Systems ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Wireless Systems ◽  
Block Code ◽  
Energy System ◽  
Maximal Ratio Combining ◽  
Receiver Diversity ◽  
Low Snr ◽  
Ber Performance

Multiple Input Multiple Output (MIMO) wireless systems are perceived a significant reorganization for upcoming wireless systems. The performance of communication systems in regards to their spectral efficiency and ability is enhanced as a result of MIMO systems. The required transmit power as for desired Bit Error Rate (BER) has been outfitted in combination with appropriate receiver diversity. The study exposed that MIMO is a further efficient energy system since accomplished a decent BER performance at low SNR, when compared with SISO, SIMO and MISO which needs high SNR to accomplish at appropriate BER performances. The multiplexing gain experienced in the multiple antenna strategies utilizing the Space Time Block Code (STBC) and Maximal Ratio Combining (MRC). The impacts of number of transmitter and receiver antennas on the MIMO system’s BER performance over Rayleigh, Rician and Weibull channels with STBC transmitter and MRC receiver is analyzed. The BER performance characteristics of MRC receiver is explored for Quadrature Phase Shift Keying (QPSK) modulation.

scholarly journals Low-complexity sparse-aware multiuser detection for large-scale MIMO systems

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Rong Ran ◽  
Hayoung Oh
Keyword(s):  
Large Scale ◽  
Mimo Systems ◽  
Minimum Mean Square Error ◽  
Multiple Input Multiple Output ◽  
Low Complexity ◽  
Finite Alphabet ◽  
Multiuser Detectors ◽  
Input Multiple Output ◽  
Error Detector ◽  
Significant Performance

AbstractSparse-aware (SA) detectors have attracted a lot attention due to its significant performance and low-complexity, in particular for large-scale multiple-input multiple-output (MIMO) systems. Similar to the conventional multiuser detectors, the nonlinear or compressive sensing based SA detectors provide the better performance but are not appropriate for the overdetermined multiuser MIMO systems in sense of power and time consumption. The linear SA detector provides a more elegant tradeoff between performance and complexity compared to the nonlinear ones. However, the major limitation of the linear SA detector is that, as the zero-forcing or minimum mean square error detector, it was derived by relaxing the finite-alphabet constraints, and therefore its performance is still sub-optimal. In this paper, we propose a novel SA detector, named single-dimensional search-based SA (SDSB-SA) detector, for overdetermined uplink MIMO systems. The proposed SDSB-SA detector adheres to the finite-alphabet constraints so that it outperforms the conventional linear SA detector, in particular, in high SNR regime. Meanwhile, the proposed detector follows a single-dimensional search manner, so it has a very low computational complexity which is feasible for light-ware Internet of Thing devices for ultra-reliable low-latency communication. Numerical results show that the the proposed SDSB-SA detector provides a relatively better tradeoff between the performance and complexity compared with several existing detectors.

PROBLEM STATEMENT OF JOINT ANTENNA SELECTION AND PRECODING IN MASSIVE MIMO COMMUNICATION SYSTEMS

2021 ◽  
Author(s):  
В.Б. КРЕЙНДЕЛИН ◽  
М.В. ГОЛУБЕВ
Keyword(s):  
Massive Mimo ◽  
Communication Systems ◽  
Mimo Systems ◽  
Antenna Selection ◽  
Multiple Input Multiple Output ◽  
Research Areas ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Legal Restrictions ◽  
Multiple Transmission

Совместный с прекодингом автовыбор антенн на приемной и передающей стороне - одно из перспективных направлений исследований для реализации технологий Multiple Transmission and Reception Points (Multi-TRP, множество точек передачи и приема) в системах со многими передающими и приемными антеннами Massive MIMO (Multiple-Input-Multiple-Output), которые активно развиваются в стандарте 5G. Проанализированы законодательные ограничения, влияющие на применимость технологий Massive MIMO, и специфика реализации разрабатываемого алгоритма в миллиметровомдиапа -зоне длин волн. Рассмотрены алгоритмы формирования матриц автовыбора антенн как на передающей, так и на приемной стороне. Сформулирована строгая математическая постановка задачи для двух критериев работы алгоритма: максимизация взаимной информации и минимизация среднеквадратичной ошибки. Joint precoding and antenna selection both on transmitter and receiver sides is one of the promising research areas for evolving toward the Multiple Transmission and Reception Points (Multi-TRP) concept in Massive MIMO systems. This technology is under active development in the coming 5G 3GPP releases. We analyze legal restrictions for the implementation of 5G Massive MIMO technologies in Russia and the specifics of the implementation of the developed algorithm in the millimeter wavelength range. Algorithms of antenna auto-selection matrices formation on both transmitting and receiving sides are considered. Two criteria are used for joint antenna selection and precoding: maximizing mutual information and minimizing mean square error.

scholarly journals MIMO Self-Encoded Spread Spectrum with Iterative Detection over Rayleigh Fading Channels

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Shichuan Ma ◽  
Lim Nguyen ◽  
Won Mee Jang ◽  
Yaoqing (Lamar) Yang
Keyword(s):  
Fading Channels ◽  
Spread Spectrum ◽  
Rayleigh Fading ◽  
Mimo Systems ◽  
Signal To Noise Ratio ◽  
Multiple Input Multiple Output ◽  
Spatial Diversity ◽  
Iterative Detection ◽  
Channel Fading ◽  
Input Multiple Output

Self-encoded spread spectrum (SESS) is a novel communication technique that derives its spreading code from the randomness of the source stream rather than using conventional pseudorandom noise (PN) code. In this paper, we propose to incorporate SESS in multiple-input multiple-output (MIMO) systems as a means to combat against fading effects in wireless channels. Orthogonal space-time block-coded MIMO technique is employed to achieve spatial diversity, and the inherent temporal diversity in SESS modulation is exploited with iterative detection. Simulation results demonstrate that MIMO-SESS can effectively mitigate the channel fading effect such that the system can achieve a bit error rate of with very low signal-to-noise ratio, from 3.3 dB for a antenna configuration to just less than 0 dB for a configuration under Rayleigh fading. The performance improvement for the case is as much as 6.7 dB when compared to an MIMO PN-coded spread spectrum system.

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