scholarly journals Linear Precoding Designs for MIMO VLC Using Multi-Color LEDs under Multiple Lighting Constraints

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 408 ◽  
Author(s):  
Ye Xiao ◽  
Yi-Jun Zhu ◽  
Zheng-Guo Sun
Keyword(s):  
High Speed ◽  
Mean Squared Error ◽  
Transmission Rate ◽  
Multiple Input Multiple Output ◽  
Visible Light Communication ◽  
Mimo Channel ◽  
Practical Applications ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Mimo Technology

Multiple-input multiple-output (MIMO) technology as an efficient approach to improve the transmission rate in visible light communication (VLC) has been well studied in recent years. In this paper, we focus on the MIMO VLC system using multi-color LEDs in the typical indoor scenario. Besides the correlation of the MIMO channel, the multi-color crosstalk interference and quadrangle chromaticity region are also considered to increase the practicality of this system. With the constraints of power, amplitude and chromaticity, an iterative algorithm to minimize mean-squared-error (MSE) is proposed to jointly design the precoder and equalizer. Our proposed algorithm provides an effective method to get the optimal precoder by updating optimization variables iteratively. As the equalizer matrix is fixed at each iteration, the main non-convex precoding design problem is transformed into a convex optimization problem and then solved. With the utilization of multi-color LEDs, our proposed precoding method would be promising to promote the practical applications of high-speed indoor optical wireless communication. Simulation results show that our proposed method owns better performance than conventional chromaticity-fixed schemes and zero-forcing precoding designs.

scholarly journals Massive MIMO and Hybrid Optimization for It's Beamforming

2019 ◽  
Vol 8 (3) ◽  
pp. 7692-7698
Keyword(s):  
Wireless Communication ◽  
High Throughput ◽  
Communication System ◽  
High Speed ◽  
Multiple Input Multiple Output ◽  
Research Work ◽  
Network Capacity ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Mimo Technology

The tremendous growth of traffic in wireless communication (WC) system has resulted in inadequate network capacity. 5th Generation (5G) is seen as next generation wireless communication system implemented with massive multiple-input multiple-output (M-MIMO) technology. It will play major role in future communication system. M-MIMO objective is high throughput and high speed. Beamforming technique is a key to high throughput objective - achieved by reduction in errors occurring in data transmission and reception. The intent of this research paper is to review - beam forming techniques implemented in M-MIMO and research work in this particular area. Paper classifies optimized beamforming techniques in detail for determining appropriate techniques that can be deployed in M-MIMO. Understanding limitations of present techniques and suggesting new approach for better throughput is outcome of retrospective analysis.

Multi-Target Direction Measurement of Bistatic MIMO Radar

2014 ◽  
Vol 556-562 ◽  
pp. 2797-2801
Author(s):  
Jing Fang Wang
Keyword(s):  
Multiple Input Multiple Output ◽  
Mimo Radar ◽  
Radar Signal ◽  
Great Success ◽  
Two Dimensional ◽  
Signal Model ◽  
Bistatic Mimo Radar ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Mimo Technology

Multiple-input multiple output (MIMO) radar has been widespread concern in the domestic and foreign researchers. Bistatic radar draws on the great success of MIMO technology in the communications field, and it has many advantages over conventional radar. The direction angles estimations of bistatic MIMO radar are researched. To contrast traditional radar DOA estimates, the direction vector of the bistatic MIMO radar is the Knonecker plot of the emission vector and reception vector, that two-dimensional direction angles is estimated. To solve this problem, the principle of bistatic MIMO radar signal model is in-depthly researched.By proposing Capon dimensionality reduction method, the two-dimensional directions of the dual-based MIMO radar are estimated, and computer simulation is to verify the effectiveness of the method.

scholarly journals Performance Enhancement in MIMO-OFDMA System

2019 ◽  
Vol 9 (2) ◽  
pp. 160-165
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Performance Enhancement ◽  
Multiple Input Multiple Output ◽  
Research Area ◽  
Ofdma System ◽  
Multiple Input ◽  
Input Multiple Output ◽  
High Speed Data ◽  
Low Complex

The systematic advancement in wireless communication has provided many significant aspects towards communication domain. However, obtaining the high-speed data transmission is still a biggest concern in various multimedia-based applications. Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing Access (MIMO-OFDMA) based communication is widespread towards research area. In addition, the combination of MIMO-OFDMA with the steering antenna can lead to improved communication efficiency and offer diversity gain without changing radio frequency (RF). This paper introduces systems for power allocation and resource allocation by A) low complex compressive channel approximation (CSCE) and b) combined parallel cancelation and Viterbi encoding / decoding (PCVed). The outcome of compressive sensing based system brings reduced Bit Error Rate (BER) and less computational complexity while the performance analysis PCVed with different approaches for 4x4 transmitter and receiver.

scholarly journals An improvement to hybrid beamforming precoding scheme for mmWave massive MIMO systems based on channel matrix

2021 ◽  
Vol 23 (1) ◽  
pp. 285
Author(s):  
Zahra Amirifar ◽  
Jamshid Abouei
Keyword(s):  
Massive Mimo ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Wireless Systems ◽  
Achievable Rate ◽  
Percentage Difference ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Hybrid Beamforming ◽  
Mimo Technology

<p>The massive multiple-input multiple-output (MIMO) technology has been applied innew generation wireless systems due to growing demand for reliability and high datarate. Hybrid beamforming architectures in both receiver and transmitter, includinganalog and digital precoders, play a significant role in 5G communication networksand have recently attracted a lot of attention. In this paper, we propose a simple andeffective beamforming precoder approach for mmWave massive MIMO systems. Wefirst solve an optimization problem by a simplification subject, and in the second step,we use the covariance channel matrixfCk=Cov(Hk)andBk=HkHHkinstead of chan-nel matrixHk. Simulation results verify that the proposed scheme can enjoy a highersum rate and energy efficiency than previous methods such as spatially sparse method,analog method, and conventional hybrid method even with inaccurate Channel StateInformation (CSI). Percentage difference of the achievable rate ofCk=Cov(Hk)andBk=HkHHkschemes compared to conventional methods are 2.51% and 48.94%, re-spectively.</p>

scholarly journals Conceiving Inferential Prototypes of MIMO Channel Models via Buckingham’s Similitude Principle for 30+ GHz through THz Spectrum

2021 ◽  
Vol 9 (3) ◽  
pp. 1-35
Author(s):  
Perambur Neelakanta ◽  
Dolores De Groff
Keyword(s):  
Multiple Input Multiple Output ◽  
Path Loss ◽  
Spatial Multiplexing ◽  
Mimo Channel ◽  
Channel Models ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Channel Statistics ◽  
Wave Range ◽  
Test Spectrum

Facilitating newer bands of ‘unused’ segments (windows) of RF spectrum falling in the mm-wave range (above 30+ GHz) and seeking usable stretches across unallocated THz spectrum, could viably be considered for Multiple Input Multiple Output (MIMO) communications. This could accommodate the growing needs of multigigabit 3G/4G applications in outdoor-based backhauls in picocellular networks and in indoor-specific multimedia networking. However, in contrast with cellular and Wi-Fi, wireless systems supporting sub-mm wavelength transreceive communications in the outdoor electromagnetic (EM) ambient could face “drastically different propagation geometry”; also, in indoor contexts, envisaging pertinent spatial-multiplexing with directional, MIMO links could pose grossly diverse propagation geometry across a number of multipaths; as such, channel-models based on stochastic features of diverse MIMO-specific links in the desired test spectrum of mm-wave/THz band are sparsely known and almost non-existent. To alleviate this niche, a method is proposed here to infer sub-mm band MIMO channel-models (termed as “prototypes”) by judiciously sharing “similarity” of details available already pertinent to traditional “models” of lower-side EM spectrum, (namely, VLF through micro-/mm-wave). Relevant method proposed here relies on the “principle of similitude” due to Edgar Buckingham. Exemplar set of “model-to-(inferential)-prototype” transformations are derived and prescribed for an exhaustive set of fading channel models as well as, towards estimating path-loss of various channel statistics in the high-end test spectrum.

scholarly journals A survey on advanced transmission technologies for high bandwidth and good signal quality for high-speed railways

2021 ◽  
Vol 23 (1) ◽  
pp. 293
Author(s):  
Abdul Rafay ◽  
Sevia Mahdaliza Idrus ◽  
Kamaludin Mohamad Yusof ◽  
Siti Hasunah Mohammad
Keyword(s):  
High Speed ◽  
Multiple Input Multiple Output ◽  
Satellite Networks ◽  
Signal Quality ◽  
High Penetration ◽  
Multiple Input ◽  
Input Multiple Output ◽  
High Bandwidth ◽  
Good Signal ◽  
Very High

Ahigh-speedrailway (HSR) has gained very high popularity for passengersdue to the fast, reliable, economical and convenient during traveling a verylong-distance journey. Thedemandfor advancedbroadbandservices such aswatching4K movies, cloud computing andonline gaming, has exponentiallyincreased fortravelerson thehigh-speedtrain(HST).The HSTcan’t providegood bandwidth to facilitate these services for travelers via existingtechnologies such as cellular networksand satellite networks because offrequent handoffs, high penetration and fading.So, the bandwidth degradesdramatically due to these issues. Research workers have developed proposalsto handle these problems by advanced transmission technologies for HSR.Until now,varioustransmissionschemeshave beensuggestedby researchworks with thefocusfor either high bandwidth or signal qualityimprovement. This paper presents a survey on advanced transmissiontechnologies for high bandwidth and good signal quality. In this paper, acomprehensive survey of the appropriate literature published that concentrateon advanced transmission methods in HSR communications in getting higherbandwidth efficiency and maximize the signal quality is presented. Advancedtransmission method can be categorized into orthogonal frequencydivisionmultiplexing (OFDM), multiple-input multiple-output (MIMO) and radio-over-fiber (RoF).

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