Performance Analysis of Massive MIMO-OFDM System Incorporated with Various Transforms for Image Communication in 5G Systems

Modern-day applications of fifth-generation (5G) and sixth-generation (6G) systems require fast, efficient, and robust transmission of multimedia information over wireless communication medium for both mobile and fixed users. The hybrid amalgamation of massive multiple input multiple output (mMIMO) and orthogonal frequency division multiplexing (OFDM) proves to be an impressive methodology for fulfilling the needs of 5G and 6G users. In this paper, the performance of the hybrid combination of massive MIMO and OFDM schemes augmented with fast Fourier transform (FFT), fractional Fourier transform (FrFT) or discrete wavelet transform (DWT) is evaluated to study their potential for reliable image communication. The analysis is carried over the Rayleigh fading channels and M-ary phase-shift keying (M-PSK) modulation schemes. The parameters used in our analysis to assess the outcome of proposed versions of OFDM-mMIMO include signal-to-noise ratio (SNR) vs. peak signal-to-noise ratio (PSNR) and SNR vs. structural similarity index measure (SSIM) at the receiver. Our results indicate that massive MIMO systems incorporating FrFT and DWT can lead to higher PSNR and SSIM values for a given SNR and number of users, when compared with in contrast to FFT-based massive MIMO-OFDM systems under the same conditions.publishersversionpublishe

Adaptive 2×2 MIMO employed Wavelet-OFDM-Radio over Fibre Transmission

Due to high peak-to-average-power ratio (PAPR) and low spectral-efficiency, the conventional Fast Fourier Transform based orthogonal frequency division multiplexing (OFDM) is losing its place to the other multicarrier modulation schemes. Alternatively, the wavelet treated multiple-input multiple-output (MIMO)-OFDM is gaining its popularity in realization of futuristic 5G networks due to proffering high spectral-efficiency, low-cost and low phase-noise. Subsequently, this work demonstrates a RF transmission system in S-band employing \times 2$MIMO-OFDM using orthogonal- and biorthogonal-wavelets with diverse phase shift keying modulation (PSK) schemes. Among the available MIMO configurations, the authors implement spatial diversity as it promises good reliability in noisy links [11]. However, the distribution of Wavelet-OFDM (W-OFDM) signals over a radio over fibre (RoF) link is critically affected by the optical sub-system non-linearity. So, the simplest \times 2$ Alamouti's space-time block code (STBC) is implemented in this work to overcome this non-linearity and to realize a less-complex detection. The work is further extended to realize an adaptive MIMO-RoF system employing W-OFDM scheme to adjust itself to a suitable available phase shift keying strategy as per the link-situation to retain an optimal balance of link-quality and spectral-efficiency

Optical Communication

Optical communication is very much useful in telecommunication systems, data processing and networking. It consists of a transmitter that encodes a message into an optical signal, a channel that carries the signal to its desired destination, and a receiver that reproduces the message from the received optical signal. It presents up to date results on communication systems, along with the explanations of their relevance, from leading researchers in this field. The chapters cover general concepts of optical communication, components, systems, networks, signal processing and MIMO systems. In recent years, optical components and other enhanced signal processing functions are also considered in depth for optical communications systems. The researcher has also concentrated on optical devices, networking, signal processing, and MIMO systems and other enhanced functions for optical communication. This book is targeted at research, development and design engineers from the teams in manufacturing industry, academia and telecommunication industries

Modelling, Dimensioning and Optimization of 5G Communication Networks, Resources and Services

This reprint aims to collect state-of-the-art research contributions that address challenges in the emerging 5G networks design, dimensioning and optimization. Designing, dimensioning and optimization of communication networks resources and services have been an inseparable part of telecom network development. The latter must convey a large volume of traffic, providing service to traffic streams with highly differentiated requirements in terms of bit-rate and service time, required quality of service and quality of experience parameters. Such a communication infrastructure presents many important challenges, such as the study of necessary multi-layer cooperation, new protocols, performance evaluation of different network parts, low layer network design, network management and security issues, and new technologies in general, which will be discussed in this book

Journal of Telecommunications and Information Technology, 2017, nr 4

kwartalni

Application of wavelets and artificial neural network for indoor optical wireless communication systems

Abstract This study investigates the use of error control code, discrete wavelet transform (DWT) and artificial neural network (ANN) to improve the link performance of an indoor optical wireless communication in a physical channel. The key constraints that barricade the realization of unlimited bandwidth in optical wavelengths are the eye-safety issue, the ambient light interference and the multipath induced intersymbol interference (ISI). Eye-safety limits the maximum average transmitted optical power. The rational solution is to use power efficient modulation techniques. Further reduction in transmitted power can be achieved using error control coding. A mathematical analysis of retransmission scheme is investigated for variable length modulation techniques and verified using computer simulations. Though the retransmission scheme is simple to implement, the shortfall in terms of reduced throughput will limit higher code gain. Due to practical limitation, the block code cannot be applied to the variable length modulation techniques and hence the convolutional code is the only possible option. The upper bound for slot error probability of the convolutional coded dual header pulse interval modulation (DH-PIM) and digital pulse interval modulation (DPIM) schemes are calculated and verified using simulations. The power penalty due to fluorescent light interference (FL I) is very high in indoor optical channel making the optical link practically infeasible. A denoising method based on a DWT to remove the FLI from the received signal is devised. The received signal is first decomposed into different DWT levels; the FLI is then removed from the signal before reconstructing the signal. A significant reduction in the power penalty is observed using DWT. Comparative study of DWT based denoising scheme with that of the high pass filter (HPF) show that DWT not only can match the best performance obtain using a HPF, but also offers a reduced complexity and design simplicity. The high power penalty due to multipath induced ISI makes a diffuse optical link practically infeasible at higher data rates. An ANN based linear and DF architectures are investigated to compensation the ISI. Unlike the unequalized cases, the equalized schemes don‘t show infinite power penalty and a significant performance improvement is observed for all modulation schemes. The comparative studies substantiate that ANN based equalizers match the performance of the traditional equalizers for all channel conditions with a reduced training data sequence. The study of the combined effect of the FLI and ISI shows that DWT-ANN based receiver perform equally well in the present of both interference. Adaptive decoding of error control code can offer flexibility of selecting the best possible encoder in a given environment. A suboptimal ?soft‘ sliding block convolutional decoder based on the ANN and a 1/2 rate convolutional code with a constraint length is investigated. Results show that the ANN decoder can match the performance of optimal Viterbi decoder for hard decision decoding but with slightly inferior performance compared to soft decision decoding. This provides a foundation for further investigation of the ANN decoder for convolutional code with higher constraint length values. Finally, the proposed DWT-ANN receiver is practically realized in digital signal processing (DSP) board. The output from the DSP board is compared with the computer simulations and found that the difference is marginal. However, the difference in results doesn‘t affect the overall error probability and identical error probability is obtained for DSP output and computer simulations

Journal of Telecommunications and Information Technology

kwartalni

Application of wavelets and artificial neural network for indoor optical wireless communication systems

This study investigates the use of error control code, discrete wavelet transform (DWT) and artificial neural network (ANN) to improve the link performance of an indoor optical wireless communication in a physical channel. The key constraints that barricade the realization of unlimited bandwidth in optical wavelengths are the eye-safety issue, the ambient light interference and the multipath induced intersymbol interference (ISI). Eye-safety limits the maximum average transmitted optical power. The rational solution is to use power efficient modulation techniques. Further reduction in transmitted power can be achieved using error control coding. A mathematical analysis of retransmission scheme is investigated for variable length modulation techniques and verified using computer simulations. Though the retransmission scheme is simple to implement, the shortfall in terms of reduced throughput will limit higher code gain. Due to practical limitation, the block code cannot be applied to the variable length modulation techniques and hence the convolutional code is the only possible option. The upper bound for slot error probability of the convolutional coded dual header pulse interval modulation (DH-PIM) and digital pulse interval modulation (DPIM) schemes are calculated and verified using simulations. The power penalty due to fluorescent light interference (FL I) is very high in indoor optical channel making the optical link practically infeasible. A denoising method based on a DWT to remove the FLI from the received signal is devised. The received signal is first decomposed into different DWT levels; the FLI is then removed from the signal before reconstructing the signal. A significant reduction in the power penalty is observed using DWT. Comparative study of DWT based denoising scheme with that of the high pass filter (HPF) show that DWT not only can match the best performance obtain using a HPF, but also offers a reduced complexity and design simplicity. The high power penalty due to multipath induced ISI makes a diffuse optical link practically infeasible at higher data rates. An ANN based linear and DF architectures are investigated to compensation the ISI. Unlike the unequalized cases, the equalized schemes don‘t show infinite power penalty and a significant performance improvement is observed for all modulation schemes. The comparative studies substantiate that ANN based equalizers match the performance of the traditional equalizers for all channel conditions with a reduced training data sequence. The study of the combined effect of the FLI and ISI shows that DWT-ANN based receiver perform equally well in the present of both interference. Adaptive decoding of error control code can offer flexibility of selecting the best possible encoder in a given environment. A suboptimal 'soft' sliding block convolutional decoder based on the ANN and a 1/2 rate convolutional code with a constraint length is investigated. Results show that the ANN decoder can match the performance of optimal Viterbi decoder for hard decision decoding but with slightly inferior performance compared to soft decision decoding. This provides a foundation for further investigation of the ANN decoder for convolutional code with higher constraint length values. Finally, the proposed DWT-ANN receiver is practically realized in digital signal processing (DSP) board. The output from the DSP board is compared with the computer simulations and found that the difference is marginal. However, the difference in results doesn‘t affect the overall error probability and identical error probability is obtained for DSP output and computer simulations.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Uticaj fedinga na komunikaciju senzorskih čvorova u bežičnim nosivim telesnim senzorskim mrežama za vojnu primenu

Svakodnevno se uvećavaju zahtevi za informacijama u procesu odlučivanja. Savremena bojišta svakako nisu izuzetak, jer se na osnovu tačnih i pravovremenih informacija mogu donositi odluke koje na kraju mogu spasiti ljudske živote, smanjiti upotrebu prekomerne sile ili pak uništenje vojne tehnike. Količine i vrste podataka koje senzorske mreže generišu na samom terenu postavljaju tehničke izazove pred komunikacionu tehniku da obezbede pravilan, potpun i bezbedan način protoka informacija. Jedan od problema koji je potrebno istražiti je komunikacija bežičnih senzorskih mreža koje imaju nove karakteristike i zahteve na komunikacionim sistemima i mrežnim protokolima, a koji se razlikuju od konvencionalnih mreža za komunikaciju podataka. Pojava fedinga u bežičnim senzorskim mrežama je sigurna, ali sam sistem svojom konfiguracijom senzorskih čvorova i kombinacijom bežičnih tehnologija čini da se interferencija u kanalu smanji i poveća kapacitet protoka samog kanala. Bežične senzorske mreže se organizuju u hijerarhiskom i ćelijskom nivou. S druge strane veliki broj ćelija utiče da se poveća i broj radio kanala, a sa povećanjem broja radio kanala dolazi do međukanalne interferencije što direktno utiče kvalitet prenosa podataka radio kanalom. Cilj je postići potreban nivo kapaciteta u prenosu i kvaliteta u prijemu signal na krajnoj tački. Dodatak, konvencionalnim RF sistemima komunikacije, u obliku FSO komunikacionih sistema predstavljaju značajno unapređenje koje može unaprediti performanse, brzine prenosa i bezbedniji prenos podataka. U radu je predložena hibridna RF/FSO mobilna senzorska mreža koja uspešno treba za prevaziđe komunikacione probleme konvencionalne RF mreže. U radu je istražena mogućnost da se kroz optički kanal u prisustva fedinga (scintilacije) prenesu kompleksniji podaci (slika, video i sl.), kao i kako u prisustvu fedinga u optičkom kanalu dolazi do degradacije podatka