scholarly journals On the Capacity of Amplitude Modulated Soliton Communication over Long Haul Fibers

Entropy ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 899
Author(s):  
Yu Chen ◽  
Iman Tavakkolnia ◽  
Alex Alvarado ◽  
Majid Safari
Keyword(s):  
Communication Systems ◽  
Channel Model ◽  
Additive White Gaussian Noise ◽  
Soliton Interaction ◽  
Capacity Limits ◽  
Model Based ◽  
Chi Squared ◽  
Optic Communication ◽  
Capacity Formulation ◽  
The Impact

The capacity limits of fiber-optic communication systems in the nonlinear regime are not yet well understood. In this paper, we study the capacity of amplitude modulated first-order soliton transmission, defined as the maximum of the so-called time-scaled mutual information. Such definition allows us to directly incorporate the dependence of soliton pulse width to its amplitude into capacity formulation. The commonly used memoryless channel model based on noncentral chi-squared distribution is initially considered. Applying a variance normalizing transform, this channel is approximated by a unit-variance additive white Gaussian noise (AWGN) model. Based on a numerical capacity analysis of the approximated AWGN channel, a general form of capacity-approaching input distributions is determined. These optimal distributions are discrete comprising a mass point at zero (off symbol) and a finite number of mass points almost uniformly distributed away from zero. Using this general form of input distributions, a novel closed-form approximation of the capacity is determined showing a good match to numerical results. Finally, mismatch capacity bounds are developed based on split-step simulations of the nonlinear Schro¨dinger equation considering both single soliton and soliton sequence transmissions. This relaxes the initial assumption of memoryless channel to show the impact of both inter-soliton interaction and Gordon–Haus effects. Our results show that the inter-soliton interaction effect becomes increasingly significant at higher soliton amplitudes and would be the dominant impairment compared to the timing jitter induced by the Gordon–Haus effect.

A Novel VLC Channel Model Based on Beam Steering Considering the Impact of Obstacle

2019 ◽  
Vol 23 (6) ◽  
pp. 1003-1007 ◽  
Author(s):  
Xi Nan ◽  
Ping Wang ◽  
Lixin Guo ◽  
Li Huang ◽  
Zhongyu Liu
Keyword(s):  
Channel Model ◽  
Beam Steering ◽  
Model Based ◽  
The Impact

scholarly journals Ray-Based Statistical Propagation Modeling for Indoor Corridor Scenarios at 15 GHz

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Qi Wang ◽  
Bo Ai ◽  
Ke Guan ◽  
David W. Matolak ◽  
Ruisi He ◽  
...  
Keyword(s):  
Communication Systems ◽  
Channel Model ◽  
Deterministic Model ◽  
Path Loss ◽  
Propagation Characteristic ◽  
Directional Antennas ◽  
Small Scale ◽  
Delay Spread ◽  
Channel Measurements ◽  
The Impact

According to the demands for fifth-generation (5G) communication systems, high frequency bands (above 6 GHz) need to be adopted to provide additional spectrum. This paper investigates the characteristics of indoor corridor channels at 15 GHz. Channel measurements with a vector network analyzer in two corridors were conducted. Based on a ray-optical approach, a deterministic channel model covering both antenna and propagation characteristic is presented. The channel model is evaluated by comparing simulated results of received power and root mean square delay spread with the corresponding measurements. By removing the impact of directional antennas from the transmitter and receiver, a path loss model as well as small-scale fading properties for typical corridors is presented based on the generated samples from the deterministic model. Results show that the standard deviation of path loss variation is related to the Tx height, and placing the Tx closer to the ceiling leads to a smaller fluctuation of path loss.

An efficient adaptive modulation technique over realistic wireless communication channels based on distance and SINR

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rahim Khan ◽  
Qiang Yang ◽  
Alam Noor ◽  
Sohaib Bin Altaf Khattak ◽  
Liang Guo ◽  
...  
Keyword(s):  
Wireless Communication ◽  
Fading Channels ◽  
Communication Systems ◽  
Additive White Gaussian Noise ◽  
Adaptive Modulation ◽  
Base Stations ◽  
Rician Fading ◽  
Available Bandwidth ◽  
Modulation Schemes ◽  
The Impact

Abstract A growing trend has been observed in recent research in wireless communication systems. However, several limitations still exist, such as packet loss, limited bandwidth and inefficient use of available bandwidth that needs further investigation and research. In light of the above limitations, this paper uses adaptive modulation under various parameters, such as signal to interference plus noise ratio (SINR), and communication channel’s distances. The primary goal is to minimize bit error rate (BER), improve throughput and utilize the available bandwidth efficiently. Additionally, the impact of Additive White Gaussian Noise (AWGN), Rayleigh and Rician fading channels on the performance of various modulation schemes are also studied. The simulation results demonstrate that our proposed technique optimally improves the BER and spectral efficiency in the long-range communication as compared to the fixed modulation schemes under the co-channel interference of surrounding base stations. The results indicate that the performance of fixed modulation schemes is suitable only either at high SINR and low distance or at low SINR and high distance values. Moreover, on the other hand, its performance was suboptimal in the entire wireless communication channel due to high distortion and attenuation. Lastly, we also noted that BER performance in the AWGN channel is better than Rayleigh and Rician channels with Rayleigh channel exhibiting poor performance than the Rician channel.

Efficient Discrete Simulation of Coded Wireless Communication Systems

2010 ◽  
pp. 143-177 ◽  
Author(s):  
Pedro J.A. Sebastião ◽  
Francisco A.B. Cercas ◽  
Adolfo V.T. Cartaxo
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Forward Error Correction ◽  
Channel Model ◽  
Additive White Gaussian Noise ◽  
Simulation Method ◽  
Potential Range ◽  
Soft Decision ◽  
Bit Error Ratio ◽  
Forward Error

Simulation can be a valuable tool for wireless communication system’s (WCS) designers to assess the performance of its radio interface. It is common to use the Monte Carlo simulation method (MCSM), although this is quite time inefficient, especially when it involves forward error correction (FEC) with very low bit error ratio (BER). New techniques were developed to efficiently evaluate the performance of the new class of TCH (Tomlinson, Cercas, Hughes) codes in an additive white Gaussian noise (AWGN) channel, due to their potential range of applications. These techniques were previously applied using a satellite channel model developed by Lutz with very good results. In this chapter, we present a simulation method, named accelerated simulation method (ASM), that provides a high degree of efficiency and accuracy, namely for lower BER, where the application of methods like the MCSM is prohibitive, due to high computational and time requirements. The present work generalizes the application of the ASM to a WCS modelled as a stochastic discrete channel model, considering a real channel, where there are several random effects that result in random energy fluctuations of the received symbols. The performance of the coded WCS is assessed efficiently, with soft-decision (SD) and hard-decision (HD) decoding. We show that this new method already achieves a time efficiency of two or three orders of magnitude for SD and HD, considering a BER = 1x10-4 , when compared to MCSM. The presented performance results are compared with the MCSM, to check its accuracy.

Effects of Inter Multi-Pulses Interference on Data Rate of UWB Systems Based on Compressed Sensing

2013 ◽  
Vol 443 ◽  
pp. 397-401
Author(s):  
Thanh Son Nguyen ◽  
Shu Xu Guo
Keyword(s):  
Compressed Sensing ◽  
Data Transmission ◽  
Communication Systems ◽  
Channel Model ◽  
Transmission Rate ◽  
Sampling Rate ◽  
Data Rate ◽  
Data Transmission Rate ◽  
The Impact ◽  
Uwb Communication

To study this issue, a new structure for UWB communication systems based on compressed sensing (CS) is proposed. This proposals focus on solving two main problems. First, building a system based on the CS to reduce the sampling rate at the receiver. Second, analyzing the impact of inter multi-pulses interference (IMI) to the ability to transmit high data rate of UWB communication systems. Experimental results show that, the IMI will be changed greatly depending on the different types of channel model. In the LOS channel model, the effects of the IMI negligible thus data transmission rate can be achieved up to several hundred Mbps. whereas for the NLOS channel models, the effects of the IMI large so data transmission rate can only reach a few Mbps.

scholarly journals A Blind Nonlinearity Compensator Using DBSCAN Clustering for Coherent Optical Transmission Systems

2019 ◽  
Vol 9 (20) ◽  
pp. 4398 ◽  
Author(s):  
Elias Giacoumidis ◽  
Yi Lin ◽  
Mutsam Jarajreh ◽  
Sean O’Duill ◽  
Kevin McGuinness ◽  
...  
Keyword(s):  
Communication Systems ◽  
Spatial Clustering ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Optical Amplification ◽  
Nonlinearity Compensation ◽  
Dbscan Clustering ◽  
Nonlinear Distortions ◽  
Optic Communication ◽  
The Impact

Coherent fiber-optic communication systems are limited by the Kerr-induced nonlinearity. Benchmark optical and digital nonlinearity compensation techniques are typically complex and tackle deterministic-induced nonlinearities. However, these techniques ignore the impact of stochastic nonlinear distortions in the network, such as the interaction of fiber nonlinearity with amplified spontaneous emission from optical amplification. Unsupervised machine learning clustering (e.g., K-means) has recently been proposed as a practical approach to the blind compensation of stochastic and deterministic nonlinear distortions. In this work, the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm is employed, for the first time, for blind nonlinearity compensation. DBSCAN is tested experimentally in a 40 Gb/s 16 quadrature amplitude-modulated system at 50 km of standard single-mode fiber transmission. It is shown that at high launched optical powers, DBSCAN can offer up to 0.83 and 8.84 dB enhancement in Q-factor when compared to conventional K-means clustering and linear equalisation, respectively.

scholarly journals Analysis and Mitigation of the Narrowband Interference Impact on IR-UWB Communication Systems

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Ehab M. Shaheen ◽  
Mohamed El-Tanany
Keyword(s):  
Fading Channel ◽  
Communication Systems ◽  
Channel Model ◽  
Closed Form Expression ◽  
Narrowband Interference ◽  
Flat Fading ◽  
Interference Signals ◽  
Interference Canceller ◽  
The Impact ◽  
Uwb Communication

The impact of narrowband interference signals on impulse radio ultrawideband (UWB) communication systems has been investigated. A closed form expression for the bit error rate performance of UWB communication system in a Log-normal flat fading channel under such impact is evaluated. The actual UWB channel model is known as a multipath fading channel; however flat fading channel model can be considered with some of the UWB wireless applications such as UWB wireless sensor networks which are characterized by size and energy constraints. Thus, a simple and low-cost one-finger Rake receiver can be used with such wireless systems. It was proven that UWB systems unavoidably suffer from the interference caused by the coexisting systems due to the restraint on their transmission power levels. To this end, we propose an interference canceller scheme which is capable of suppressing the impact of such interference and enhancing the performance of UWB communication systems. The interference canceller scheme performance is also investigated in various scenarios of operation such as the presence of multiple narrowband interference signals, symbol timing error, and a comparison with a notch filter-based case.

scholarly journals Modeling of Downlink Interference in Massive MIMO 5G Macro-Cell

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 597
Author(s):  
Kamil Bechta ◽  
Cezary Ziółkowski ◽  
Jan M. Kelner ◽  
Leszek Nowosielski
Keyword(s):  
Power Distribution ◽  
Communication Systems ◽  
Channel Model ◽  
Radio Channel ◽  
Angular Separation ◽  
Simulation Method ◽  
Antenna System ◽  
Propagation Model ◽  
Simulation Results ◽  
The Impact

Multi-beam antenna systems are the basic technology used in developing fifth-generation (5G) mobile communication systems. In practical implementations of 5G networks, different approaches are used to enable a massive multiple-input-multiple-output (mMIMO) technique, including a grid of beams, zero-forcing, or eigen-based beamforming. All of these methods aim to ensure sufficient angular separation between multiple beams that serve different users. Therefore, ensuring the accurate performance evaluation of a realistic 5G network is essential. It is particularly crucial from the perspective of mMIMO implementation feasibility in given radio channel conditions at the stage of network planning and optimization before commercial deployment begins. This paper presents a novel approach to assessing the impact of a multi-beam antenna system on an intra-cell interference level in a downlink, which is important for the accurate modeling and efficient usage of mMIMO in 5G cells. The presented analysis is based on geometric channel models that allow the trajectories of propagation paths to be mapped and, as a result, the angular power distribution of received signals. A multi-elliptical propagation model (MPM) is used and compared with simulation results obtained for a statistical channel model developed by the 3rd Generation Partnership Project (3GPP). Transmission characteristics of propagation environments such as power delay profile and antenna beam patterns define the geometric structure of the MPM. These characteristics were adopted based on the 3GPP standard. The obtained results show the possibility of using the presented novel MPM-based approach to model the required minimum separation angle between co-channel beams under line-of-sight (LOS) and non-LOS conditions, which allows mMIMO performance in 5G cells to be assessed. This statement is justified because for 80% of simulated samples of intra-cell signal-to-interference ratio (SIR), the difference between results obtained by the MPM and commonly used 3GPP channel model was within 2 dB or less for LOS conditions. Additionally, the MPM only needs a single instance of simulation, whereas the 3GPP channel model requires a time-consuming and computational power-consuming Monte Carlo simulation method. Simulation results of intra-cell SIR obtained this way by the MPM approach can be the basis for spectral efficiency maximization in mMIMO cells in 5G systems.

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