scholarly journals Measured Performance Comparisons between Spatial Multiplexing and Beamforming Arrays in the 28 GHz Band

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Dazhi Piao ◽  
Xingning Jia ◽  
Xiaochuan Ma ◽  
Qingxin Guo ◽  
Zengrui Li
Keyword(s):  
Mimo System ◽  
Signal To Noise Ratio ◽  
Ergodic Capacity ◽  
High Gain ◽  
Spatial Multiplexing ◽  
Robust Performance ◽  
Signal To Noise ◽  
Channel Matrix ◽  
Capacity Gain ◽  
Communication Distance

A spatial multiplexing (SM) array and a beamforming (BF) array with similar antenna size working at 28 GHz are designed and fabricated. In the SM array, a 4 × 4 MIMO system is realized with each port composed of a four-element subarray. In the BF array, the whole 16 elements are used to formulate a high-gain array. The measured S-parameters are in agreement with the simulated results. For both arrays, the channel capacities are computed by the measured channel matrix and signal-to-noise ratio (SNR) in an office room. Results show that capacity of the SM system is larger than that of the BF system, although the gain of BF array is about 5 dB larger than that of the SM array. However, the capacity of the SM array depends heavily on SNR; specifically, for the 1 dBm transmit power, communication distance R=25 cm, the ergodic capacity of the SM system is 2.76 times that of the BF system, and if R=250 cm, the capacity gain is reduced to 1.45. Furthermore, compared with the BF array, the SM array has a more robust performance over antenna misalignment, because of the wider beamwidth.

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 The Effect of the Eigenvalues of the Zero-Forcing Detector on Its Performance in the Space-Division Multiplexing System

2021 ◽  
Vol 14 (1) ◽  
pp. 340-355
Author(s):  
Ashraf Hassan ◽  
◽  
Ali Saleh ◽  
Keyword(s):  
Correlation Matrix ◽  
Signal To Noise Ratio ◽  
Channel Noise ◽  
Noise Power ◽  
Zero Forcing ◽  
Signal To Noise ◽  
Channel Correlation ◽  
Channel Matrix ◽  
Space Division Multiplexing ◽  
Space Division

Zero-Forcing (ZF) detector is used in Space-Division Multiplexing (SDM) receiver to remove interference among the received symbols. Previous works showed that the power of channel noise is enhanced in the output of the ZF detector. They recommend using the ZF detector when the received Signal-to-Noise Ratio (SNR) is high. This work proves that the performance of the ZF detector depends on the eigenvalues of the channel correlation matrix. The paper shows that if the sum of the eigenvalues of this correlation matrix is equal to the rank of the channel matrix, the ZF detector will not enhance noise power at its outputs. Moreover, if the sum of the eigenvalues is smaller than the rank of the channel matrix, the ZF detector will reduce noise power at its outputs. In this work, a theorem, which demonstrates the performance of the ZF detector in SDM receiver, is introduced and proved. The proposed work uses smart antennas in the transmitter and receiver to control the elements and eigenvalues of the channel matrix. The introduced theorem and a complete SDM receiver with ZF detector are simulated and evaluated at different conditions with different criteria. A real-time SDM receiver with ZF detector is also implemented and evaluated. The simulation and implementation results are shown at the end of this study. The results of the proposed systems show that a ZF detector can be used to remove interference in the SDM system without enhancing the channel noise.

Ergodic Channel Capacity of MIMO Transmission in Spatial Correlated-Fading

2013 ◽  
Vol 284-287 ◽  
pp. 2637-2641
Author(s):  
Joy Long Zong Chen ◽  
Lu Tsou Yeh ◽  
Chieh Wen Liou
Keyword(s):  
Channel Capacity ◽  
Mimo System ◽  
Signal To Noise Ratio ◽  
Moment Generating Function ◽  
Ergodic Average ◽  
System Evaluation ◽  
Signal To Noise ◽  
Average Channel Capacity ◽  
Correlated Fading ◽  
Mimo Transmission

In this article the MGF (moment generating function) obtained to determine the ergodic (average) channel capacity, and which is by passing the difficulty in calculating the pdf (probability density function) of SNR (signal-to-noise ratio) traditionally. Some numerical results are offered for validating the accuracy the theoretical deriver formulas. Furthermore, many plots work out from combination with different number of transmitter and receiver for comparison. It is valuable to note that the more the antenna numbers the larger channel capacity is not acceptable when the correlation coefficient is taken into account the system evaluation of a MIMO system.

scholarly journals Performance Analysis on Spatial MFSK Modulation with Energy Detection

2021 ◽  
Author(s):  
Shuaijun Li ◽  
Hongbing Qiu ◽  
lin zheng ◽  
Chao Yang
Keyword(s):  
Mimo System ◽  
Signal To Noise Ratio ◽  
Multiple Input Multiple Output ◽  
Energy Detection ◽  
Symbol Error Rate ◽  
Spatial Multiplexing ◽  
Optimal Decision ◽  
High Signal ◽  
Mimo Detection ◽  
Input Multiple Output

Abstract Noncoherent multiple-input multiple-output （MIMO）detection in fast fading environments has received attention in recent years since less influence by factors such as phase fluctuations and the low requirements for channel estimation and synchronization. Spatial MFSK modulation with energy detection is different from conventional noncoherent MIMO in that it can obtain higher spatial multiplexing, but with the introduction of the nonlinear square-law operation, the analysis of its detection performance needs to be solved. This paper analyzes the theoretical symbol error rate (SER) performance of the Spatial MFSK modulation with energy detection. The noise of the MIMO system by energy detection conform to the generalized gamma distribution. Based on this distribution, the optimal decision rule of the system and the theoretical SER formula are derived. Numerical results show that the theoretical SER formula fits well with the simulation results of the system under the condition of high signal-to-noise ratio (SNR).

scholarly journals Capacity Analysis of Multiple-input-multiple-output System Over Rayleigh and Rician Fading Channel

2019 ◽  
Vol 3 (2) ◽  
pp. 70-74
Author(s):  
Yazen Saifuldeen Mahmood ◽  
Ghassan Amanuel Qasmarrogy
Keyword(s):  
Channel Capacity ◽  
Transmission Rate ◽  
Mimo System ◽  
Signal To Noise Ratio ◽  
Multiple Input Multiple Output ◽  
Ergodic Capacity ◽  
Rician Fading ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Water Filling Algorithm

This paper aims to analyze the channel capacity in terms of spectral efficiency of a multiple-input-multiple-output (MIMO) system when channel state information (CSI) is known using water-filling algorithm and unknown at the transmitter side which it has been shown that the knowledge of the CSI at the transmitter enhancing the performance, the random Rayleigh and Rician channel models are assumed. Ergodic capacity and outage probability are the most channel capacity definitions which are investigated in this study. MATLAB code is devised to simulate the capacity of MIMO system for different numbers of antenna nodes versus different signal-to-noise ratio (SNR) values. In addition, the outage capacity probabilities for vary transmission rate and SNR are discussed.

Research on Multiuser Scheduling Algorithm Based on the Frobenius-Norm of Channel Matrix

2014 ◽  
Vol 687-691 ◽  
pp. 4110-4113
Author(s):  
Yong Bo Zhang ◽  
Jian Xin Li ◽  
Yan Ping Li
Keyword(s):  
Power Distribution ◽  
Mimo System ◽  
Signal To Noise Ratio ◽  
Scheduling Algorithm ◽  
Base Station ◽  
Frobenius Norm ◽  
Channel Matrix ◽  
Water Filling ◽  
Multiuser Scheduling ◽  
Service Application

In MU-MIMO system when a base station sometimes has not enough resources to satisfy the service application from each user, we should arrange to communicate selectively for a certain number of users according to some appropriate method, i.e. multiuser scheduling. Given necessary channel state information this paper investigated the relationship between the norm of channel matrix and channel quality and studied multiuser scheduling algorithm typically based on the Frobenius-norm of channel matrix which was simulated respectively for equal power distribution and water-filling power distribution in MU-MIMO system model. The simulation result showed that at the same transmitted signal-to-noise ratio (SNR) such scheduling algorithm could be able to lower the bit error rate (BER) effectively and improve the receive capability in comparison to random scheduling.

scholarly journals PROBABILISTIC ANALYSIS OF GENERALISED STATISTIC MODEL FOR MULTIPATH CHANNEL OF SIMO SISTEMS WITH FADING AND CORRELATED SHADOWING

2021 ◽  
Vol 20 (3) ◽  
pp. 727-749
Author(s):  
Aleksey Gvozdarev ◽  
Pavel Patralov
Keyword(s):  
Order Statistics ◽  
Information Transfer ◽  
Channel Model ◽  
Signal To Noise Ratio ◽  
Ergodic Capacity ◽  
Higher Order ◽  
Higher Order Statistics ◽  
Signal To Noise ◽  
Correlated Shadowing ◽  
Channel Parameters

The paper considers the problem of analysis of the information transmission process by multi-element communication systems in presence of a multipath signal propagation channel. To generalize the propagation effects, the model of the κ–μ fading channel with correlated shadowing was assumed, and the technology used for organizing a multi-element system was the SIMO system, equipped with the maximum-ration combiner of the signal on the receiving side. To describe the characteristics of the information transfer process, an approach based on the higher-order statistics of the ergodic capacity was used. Closed-form analytical expressions for arbitrary-order capacity higher-order statistics were obtained for the channel model under consideration. The behavior of the first four statistics (ergodic capacity, its reliability, skewness and kurtosis coefficients) is analyzed depending on the channel parameters (the number of multipath propagation clusters, the ratio of power of the dominant components to the total power of multipath waves, the degree of shadowing of the dominant components, and the shadowing correlation coefficient). Within the framework of the study, 4 distinct situations of the assumed channel model behavior were considered, which significantly differ in their properties. It is noted that, in contrast to the capacity, its higher-order statistics are significantly more sensitive to the channel parameters and, as a result, are more significant indicators of fluctuations in the information transfer rate within the communication channel. The existence of a pronounced extremum (minimum) of the reliability ergodic capacity dependence from the signal-to-noise ratio was established. It should be accounted for in practical applications, when the requirements of the signal-to-noise ratio that guarantees the desired communication link quality are set.

A Column Orthogonality Space-Time-Frequency Coding Schemes

2013 ◽  
Vol 846-847 ◽  
pp. 1044-1047
Author(s):  
Chao Shao ◽  
Cun Yao Xu ◽  
Xin Shi
Keyword(s):  
Signal To Noise Ratio ◽  
Space Time ◽  
Signal To Noise ◽  
Orthogonality Space ◽  
Channel Matrix ◽  
Time Frequency ◽  
Coding Scheme ◽  
Coding Schemes ◽  
Frequency Coding ◽  
Orthogonal Space

A column orthogonal space-time-frequency coding scheme is presented, its induced cost207 transmit environment channel matrix has greater determinant value, which will lead result in amplifying the signal-to noise ratio of system, and improving the performance of the system. Computer simulations confirm the theory of the article.

scholarly journals On the Capacity of MIMO Weibull-Gamma Fading Channels in Low SNR Regime

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Keerti Tiwari ◽  
Davinder S. Saini ◽  
Sunil V. Bhooshan
Keyword(s):  
Fading Channels ◽  
Mimo Systems ◽  
Mimo System ◽  
Minimum Mean Square Error ◽  
Block Codes ◽  
Performance Comparison ◽  
Spatial Multiplexing ◽  
Capacity Analysis ◽  
Signal To Noise ◽  
Low Snr

We present capacity analysis for multiple-input multiple-output (MIMO) system under a low signal-to-noise ratio (SNR) regime. We have selected a composite fading channel that considers Weibull fading for multipath and gamma fading for shadowing. We have presented the analysis in a detailed form for three different techniques, namely, spatial multiplexing (SM) with optimal detection, SM with minimum mean square error (MMSE) detection, and orthogonal space-time block codes (OSTBC). Because capacity analysis at arbitrary signal-to-noise (SNR) is stringent, a low SNR regime is considered to achieve a positive rate and wideband slope. The improvement is the result of minimizing energy per information bit (Eb). For the first time, closed-form expressions are evaluated for the capacity of MIMO systems at low SNR under WG fading channels which facilitate the performance comparison for proposed techniques.

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