Channel Model Optimization with Reflection Residual Component for Indoor MIMO-VLC System

2017 ◽  
Vol 39 (1) ◽  
Author(s):  
Yong Chen ◽  
Tengfei Li ◽  
Huanlin Liu ◽  
Yichao Li

AbstractA fast channel modeling method is studied to solve the problem of reflection channel gain for multiple input multiple output-visible light communications (MIMO-VLC) in the paper. For reducing the computational complexity when associating with the reflection times, no more than 3 reflections are taken into consideration in VLC. We think that higher order reflection link consists of corresponding many times line of sight link and firstly present reflection residual component to characterize higher reflection (more than 2 reflections). We perform computer simulation results for point-to-point channel impulse response, receiving optical power and receiving signal to noise ratio. Based on theoretical analysis and simulation results, the proposed method can effectively reduce the computational complexity of higher order reflection in channel modeling.

2013 ◽  
Vol 441 ◽  
pp. 920-923
Author(s):  
Yong Wang ◽  
Xue Mei Bi

Based on the analysis of ultraviolet single scattering channel model, the attenuation model of fog and its impact on signal attenuation is investigated. Under foggy environment, the study on the performance of ultraviolet communications is carried, simulation results show that the fog will not only make ultraviolet communication system BER performance deterioration, but also make information transmission rate substantially lowered. In addition, to guarantee a certain system performance indicators, the average transmitted optical power will have higher requirements.


Author(s):  
Jianzheng Li ◽  
Fei Li ◽  
Wei Ji ◽  
Yulong Zou ◽  
Chunguo Li

In this paper a three-dimension (3D) multiple-input multiple-output (MIMO) channel model is derived by considering the elevation dimension and the azimuth dimension together. To get a more accurate performance analysis for 3D MIMO channel, both Tx and Rx correlation matrices are derived, respectively, in closed form, which consist of 3D Kronecker channel model. This novel 3D Kronecker channel model is developed for arbitrary antenna arrays with non-isotropic antenna patterns and also for any propagation environment of 3D MIMO systems. In order to quantify the performance of 3D MIMO systems, the capacity in multi-user cases is analyzed. Simulation results validate the proposed 3D Kronecker channel model and study the impact of elevation and azimuth angular spread and that of Rx antenna element spacing on the correlation. The proposed capacity analysis in multi-user cases for 3D MIMO systems is also verified by simulation.


2021 ◽  
Vol 10 (1) ◽  
pp. 36-45
Author(s):  
M. M. Tamaddondar ◽  
N. Noori

In this paper, a novel 3 dimensional (3D) approach is proposed for precise modeling of massive multiple input multiple output (M-MIMO) channels in millimeter wave (mmW) frequencies. This model is based on both deterministic and statistic computations to extract characteristics of the propagation channel. In order to increase algorithm execution speed, the physical channel is divided into two regions. The first region refers to those parts of the channel which can be mapped with simple planes such as walls, ramps and etc. The second region is usually complex which is defined by considering the channel with physical clusters. These physical clusters yield multipath components (MPCs) with similar angles of arrival (AoA) and time delay. The ray-tracing algorithm is utilized to find ray paths from transmitter (Tx) to receiver (Rx). Some characteristics of MPCs in each cluster are defined according to some appropriate statistical distribution. The non-stationary property of M-MIMO along the antenna array axis is considered in the algorithm. Due to the correspondence between the propagation environment and scatters, the accuracy of the model is highly increased. To evaluate the proposed channel model, simulation results are compared with some measurements reported in the literature.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mustafa B. Al-Deen ◽  
Mazin Ali A. Ali ◽  
Zeyad A. Saleh

Abstract This paper presents a new approach to discover the effect of depth water for underwater visible light communications (UVLC). The quality of the optical link was investigated with varying water depth under coastal water types. The performance of the UVLC with multiple input–multiple output (MIMO) techniques was examined in terms of bit error rate (BER) and data rate. The theoretical result explains that there is a good performance for UVLC system under coastal water.


Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 948
Author(s):  
Jenn-Kaie Lain ◽  
Yan-He Chen

By modulating the optical power of the light-emitting diode (LED) in accordance with the electrical source and using a photodetector to convert the corresponding optical variation back into electrical signals, visible light communication (VLC) has been developed to achieve lighting and communications simultaneously, and is now considered one of the promising technologies for handling the continuing increases in data demands, especially indoors, for next generation wireless broadband systems. During the process of electrical-to-optical conversion using LEDs in VLC, however, signal distortion occurs due to LED nonlinearity, resulting in VLC system performance degradation. Artificial neural networks (ANNs) are thought to be capable of achieving universal function approximation, which was the motivation for introducing ANN predistortion to compensate for LED nonlinearity in this paper. Without using additional training sequences, the related parameters in the proposed ANN predistorter can be adaptively updated, using a feedback replica of the original electrical source, to track the LED time-variant characteristics due to temperature variation and aging. Computer simulations and experimental implementation were carried out to evaluate and validate the performance of the proposed ANN predistorter against existing adaptive predistorter schemes, such as the normalized least mean square predistorter and the Chebyshev polynomial predistorter.


Author(s):  
Xiuhua Fu ◽  
Tian Ding ◽  
Rongqun Peng ◽  
Cong Liu ◽  
Mohamed Cheriet

AbstractThis paper studies the communication problem between UAVs and cellular base stations in a 5G IoT scenario where multiple UAVs work together. We are dedicated to the uplink channel modeling and the performance analysis of the uplink transmission. In the channel model, we consider the impact of 3D distance and multi-UAVs reflection on wireless signal propagation. The 3D distance is used to calculate the path loss, which can better reflect the actual path loss. The power control factor is used to adjust the UAV's uplink transmit power to compensate for different propagation path losses, so as to achieve precise power control. This paper proposes a binary exponential power control algorithm suitable for 5G networked UAV transmitters and presents the entire power control process including the open-loop phase and the closed-loop phase. The effects of power control factors on coverage probability, spectrum efficiency and energy efficiency under different 3D distances are simulated and analyzed. The results show that the optimal power control factor can be found from the point of view of energy efficiency.


2014 ◽  
Vol 610 ◽  
pp. 339-344
Author(s):  
Qiang Guo ◽  
Yun Fei An

A UCA-Root-MUSIC algorithm for direction-of-arrival (DOA) estimation is proposed in this paper which is based on UCA-RB-MUSIC [1]. The method utilizes not only a unitary transformation matrix different from UCA-RB-MUSIC but also the multi-stage Wiener filter (MSWF) to estimate the signal subspace and the number of sources, so that the new method has lower computational complexity and is more conducive to the real-time implementation. The computer simulation results demonstrate the improvement with the proposed method.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shabana Urooj ◽  
Norah Muhammad Alwadai ◽  
Vishal Sorathiya ◽  
Sunil Lavadiya ◽  
Juveriya Parmar ◽  
...  

Abstract This article has indicated optical coherent differential polarization (DP) 16 quadrature amplitude modulation (QAM) transceiver systems with free-space optical (FSO) channel in the presence of differential coding scheme. The optical coherent DP 16-QAM receiver executes the reverse process conversion of the optical signal into an electrical one that is detected to the users. The proposed optical coherent DP-16 QAM transceiver systems based FSO channel model with differential coding has been presented and compared with the previous model. However, the simulation results have confidence realization about the superiority of the proposed simulation model. Hence the proposed optical coherent DP-16 QAM transceiver systems simulation model with differential coding is verified and validated the enhancement performance based on simulation performance parameters.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Yoshio Karasawa ◽  
Katsuhiro Nakada ◽  
Guijiang Sun ◽  
Rikako Kotani

We present four new developments for a multiple-input multiple-output (MIMO) over-the-air measurement system based on our previous studies. The first two developments relate to the channel model for multipath environment generation. One is a further simplification of the circuit configuration without performance degradation by reducing the number of delay generation units, which dominate the performance limit when implementing the circuit on a field-programmable gate array (FPGA). The other is to realize spatial correlation characteristics among the input ports on the transmission side, whereas the previously proposed channel model did not consider this correlation. The third development involves the details of implementing the MIMO fading emulator on an FPGA as a two-stage scheme. The fourth is the demonstration of application examples of the developed system.


Information ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 210
Author(s):  
Xiaoyang Liu ◽  
Hengyang Liu ◽  
Chao Liu ◽  
Ya Luo

Because of the high BER (Bit Error Rate), low time delay and low channel transmission efficiency of HAPS (High Altitude Platform Station) in the near space. The link budget of HAPS and channel model are proposed in this paper. According to the channel characteristic, the channel model is set up, combined with different CNR (Carrier Noise Ratio), elevation angle, coding situations of wireless communication link by using Hamming code, PSK (Pulse Shift Keying) and Golay code respectively, then the situations of link quality and BER are analyzed. The simulation results show that the established model of the link budget and channel are suitable for the theoretical analysis results. The elevation of the HAPS communication link is smaller while the BER is increasing. The case of channel in the coding is better than in the un-coded situation. When every bit power and thermal noise power spectral density is larger, the BER of the HAPS communication link is becoming smaller.


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