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.

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 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.

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.

Overview of Fading Channel Modeling

2010 ◽  
Vol 56 (4) ◽  
pp. 339-344
Author(s):  
Krystyna Noga ◽  
Beata Pałczyńska
Keyword(s):  
Fading Channel ◽  
Communication Systems ◽  
Channel Modeling ◽  
Flat Fading

Overview of Fading Channel ModelingVisSim and LabVIEW based approaches are proposed and implemented to demonstrate fading in the communication systems. The introduction to fading, models for flat fading like Rayleigh, Weibull, Nakagami-mand the results of simulations are presented.

scholarly journals Downlink Linear Precoders Based on Statistical CSI for Multicell MIMO-OFDM

2017 ◽  
Vol 2017 ◽  
pp. 1-18
Author(s):  
Ebrahim Baktash ◽  
Chi-Heng Lin ◽  
Xiaodong Wang ◽  
Mahmood Karimi
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Channel Model ◽  
Matrix Theory ◽  
Covariance Structure ◽  
Optimal Solution ◽  
Closed Form Expression ◽  
Ofdm Systems ◽  
Precoder Design ◽  
Mimo Ofdm

With 5G communication systems on the horizon, efficient interference management in heterogeneous multicell networks is more vital than ever. This paper investigates the linear precoder design for downlink multicell multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems, where base stations (BSs) coordinate to reduce the interference across space and frequency. In order to minimize the overall feedback overhead in next-generation systems, we consider precoding schemes that require statistical channel state information (CSI) only. We apply the random matrix theory to approximate the ergodic weighted sum rate of the system with a closed form expression. After formulating the approximation for general channels, we reduce the results to a more compact form using the Kronecker channel model for which several multicarrier concepts such as frequency selectivity, channel tap correlations, and intercarrier interference (ICI) are rigorously represented. We find the local optimal solution for the maximization of the approximate rate using a gradient method that requires only the covariance structure of the MIMO-OFDM channels. Within this covariance structure are the channel tap correlations and ICI information, both of which are taken into consideration in the precoder design. Simulation results show that the rate approximation is very accurate even for very small MIMO-OFDM systems and the proposed method converges rapidly to a near-optimal solution that competes with networked MIMO and precoders based on instantaneous full CSI.

scholarly journals Energy Harvesting Enabled Full-Duplex Cooperative Relaying System over Fisher-Snedecor F-Distribution Fading Channel

2021 ◽  
pp. 82-90
Author(s):  
Kehinde O. Odeyemi ◽  
◽  
Pius A. Owolawi
Keyword(s):  
Energy Harvesting ◽  
Closed Form ◽  
System Performance ◽  
Fading Channel ◽  
Cooperative Relaying ◽  
Full Duplex ◽  
Closed Form Expression ◽  
Form Expression ◽  
The Impact ◽  
Relaying System

In this paper, the performance of an Energy Harvesting (EH) enabled full-duplex cooperative decode-and-forward (DF) relaying system is investigated over the Fisher-Snedecor F-fading channel. The system energy-constrained relay unit utilizes time-switching relay protocol for scavenging energy from the source signal and information transmission to the destination. To quantify the system performance, the exact analytical closed-form expression for the system outage probability is derived, and then used to obtain the analytical expression for the average throughput of delay-limited transmission mode. Moreover, the exact closed-form expression for the system Ergodic capacity is derived through which the average delay-tolerant throughput is determined for the system. In addition, the results demonstrate the impact of fading and shadowing severity on the system performance. It also is noticeable from the results that the performance of system is strongly affected by the loop back interference from the relay node. Finally, the accuracy of the derived analytical expressions is then validated through the Monte-Carlo simulation.

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