Design and evaluation of optical laser diodes LD positioning arrangement and multiple input/ multiple output MIMO-OFDM systems

Optical communication system for the next generation of wireless communication systems are an exciting, unparalleled new technology. This paper presents a new visible light positioning algorithm system based on position by utilized neural network, which depending on directly measured received signal strength (RSS) information of 3D coordinates. This algorithm is called light positioning algorithm neural network (LPANN) which used 5 laser diodes LDs, each one consists of 5×5 LD chips. In addition, a novel multi Input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) based VLC systems generalized laser diodes (LD) modulation scheme as second part of this paper that is called Zero Forcing Equalizer Neural network ZFENN algorithm which based on 4 × 4 optical MIMO-VLC. It is accomplished by using LD index modulation and spatial multiplexing. Actual and imaginary parts of the complex time domain OFDM signals are therefore separated first and then, bipolar signals are transmitted through VLC channels by encoding sign-information in LD indexes. In addition, a novel receiver configuration is also suggested for flat frequency or limited channel scenarios. Based on the results of this analysis, the positioning accuracy have been improved, so this is lead to enhance data rate. While, by using the second part of the MIMO-OFDM system that leads to enhancing the SNR and BER more than 10-4, which are introduced to eliminate multi-user interference (MUI)

Performance analysis of image transmission with various channel conditions/modulation techniques

This paper investigates the impact of different modulation techniques for digital communication systems that employ quadrature phase shift keying (QPSK) and quadrature amplitude modulation (16-QAM and 64-QAM) to transmit images over AWGN and Rayleigh fading channels for the cellular mobile networks. In the further steps, wiener and median filters has been adopted to the simulation are used at the receiver side to remove the impulsive noise present in the received image. This work is performed to evaluate the transmission of two dimensional (2D) gray-scale and color-scale (RGB) images with different values from signal to noise ratios (SNR), such as; (5, 10 and 15) dB over different channels. The correct conclusions are made by comparing many of the observed Matlab simulation results. This was carried out through the results that measure the quality of received image, which is analyzes in terms of SNRimage peak signal to noise ratio (PSNR) and mean square error (MSE)

Performance analysis of image transmission with various channel conditions/modulation techniques

This paper investigates the impact of different modulation techniques for digital communication systems that employ quadrature phase shift keying (QPSK) and quadrature amplitude modulation (16-QAM and 64-QAM) to transmit images over AWGN and Rayleigh fading channels for the cellular mobile networks. In the further steps, wiener and median filters has been adopted to the simulation are used at the receiver side to remove the impulsive noise present in the received image. This work is performed to evaluate the transmission of two dimensional (2D) gray-scale and color-scale (RGB) images with different values from signal to noise ratios (SNR), such as; (5, 10 and 15) dB over different channels. The correct conclusions are made by comparing many of the observed Matlab simulation results. This was carried out through the results that measure the quality of received image, which is analyzes in terms of SNRimage peak signal to noise ratio (PSNR) and mean square error (MSE)

Review of minimizing a vertical handover in a heterogeneous wireless network.

Nowadays many different types of networks communicate among themselves to form heterogeneous ­networks. Vertical handovers between them are required to supply ongoing internet access to mobile nodes who switch from one coverage area to another with different characteristics. Mobility management techniques between heterogeneous network are necessary to reduce latency time and professionally treat the insufficient radio access resources to indemnity specific quality of service. This paper reviews literatures that are related to minimizing a ­vertical ­handover in heterogeneous wireless networks. This paper reviews literatures that are related to minimizing a vertical handover in heterogeneous wireless networks. This review investigated various handover management technologies for providing pure mobility between different access techniques such as GPRS, UMTS, and WI-FI. More of these solutions used mobile IP (MIP), transmission control protocol (TCP), stream control transmission protocol (SCTP) and session initiation protocol (SIP) to support integration between WLAN and UMTS. From the review we conclude that SCTP is much more robust against packet loss and delay ­compared to TCP, SIP, and MIP. This fact makes SCTP a potential scheme for heterogeneous wireless networks

Handover parameters optimisation techniques in 5G networks

The massive growth of mobile users will spread to significant numbers of small cells for the Fifth Generation (5G) mobile network, which will overlap the fourth generation (4G) network. A tremendous increase in handover (HO) scenarios and HO rates will occur. Ensuring stable and reliable connection through the mobility of user equipment (UE) will become a major problem in future mobile networks. This problem will be magnified with the use of suboptimal handover control parameter (HCP) settings, which can be configured manually or automatically. Therefore, the aim of this study is to investigate the impact of different HCP settings on the performance of 5G network. Several system scenarios are proposed and investigated based on different HCP settings and mobile speed scenarios. The different mobile speeds are expected to demonstrate the influence of many proposed system scenarios on 5G network execution. We conducted simulations utilizing MATLAB software and its related tools. Evaluation comparisons were performed in terms of handover probability (HOP), ping-pong handover probability (PPHP) and outage probability (OP). The 5G network framework has been employed to evaluate the proposed system scenarios used. The simulation results reveal that there is a trade-off in the results obtained from various systems. The use of lower HCP settings provides noticeable enhancements compared to higher HCP settings in terms of OP. Simultaneously, the use of lower HCP settings provides noticeable drawbacks compared to higher HCP settings in terms of high PPHP for all scenarios of mobile speed. The simulation results show that medium HCP settings may be the acceptable solution if one of these systems is applied. This study emphasises the application of automatic self-optimisation (ASO) functions as the best solution that considers user experience

Adaptive Modulation and Superposition Coding for MIMO Data Transmission Using Unequal Error Protection and Ordered Successive Interference Cancellation Techniques

This paper proposes and discusses an efficient multiple input multiple output (MIMO) system for adaptive modulation coding (AMC) based on unequal error protection (UEP) and superposition coding (SPC) by exploiting the features of sub channel partitioning. Using AMC, an appropriate order of modulation and code rate to suit the channel state information (CSI) can be selected. The realization of UEP is achieved through adaptive allocation and transmission of high and low-priority data signals over high and low quality sub channels respectively. A multistage decoding (MSD) receiver with the ordered successive interference cancellation (OSIC) technique is employed in the receiver by using two linear receiver signal combiner (RSC) techniques: zero-forcing (ZF) and minimum mean square error (MMSE). The data priority can be distinguished by the signal-to-noise ratio (SNR) and can be categorized as mode-B and mode-G. The simulation results show that the SNR performance enhancement for the UEP- MIMO scheme is approximately 9.4 dB compared to the others schemes. In addition, for the UEP-MIMO scheme, the overall data system transmission from mode-B outperforms that of mode-G with SNR gains of 8.2 dB compared to the 7.5 dB for the UEP-SISO scheme. Also, MMSE-SPC also outperforms the ZF-SPC with a 3 dB SNR at a bit error rate (BER) of 10-3

Performance enhancement of SCM/WDM-RoF-XGPON system for bidirectional transmission with square root module

The 10-Gigabit Passive Optical Network (GPON), also known as (XGPON), is a key technology for the next generation of optical fibre communication systems that can improve reliability data rate. However, the increment in the transmission distance and data rate will lead to increased dispersion. This paper proposes a model based on the Sub-Carrier Multiplexing/Wavelength Division Multiplexing-Radio over Fibre-10-Gigabit Passive Optical Network system (SCM/WDM-RoF-XGPON) for Radio Frequency (RF) using a conventional Optical Network Unit (ONU) with the Square Root Module (SRM) on the side of the receiver. It is connected to a central office Optical Line Terminal (OLT) via an access network for multi-channel optical fibre transfers with a distance of 80 km and at 10 Gbps data rate. The Optisystem 15 simulation software is used to evaluate the proposed system based on the Bit Error Rate (BER), Quality factor (Q-factor) and eye diagram. The proposed system of bidirectional fibre links uses 1270 nm and 1577 nm wavelengths for uplink and downlink transmissions, respectively. The performance is further enhanced by using SRM to compensate for the square law characteristics, making it suitable for broadband services. Due to the utilisation of SRM in the architecture, the reported results reveal a double enhancement in successful transition performance at an optical fibre length of 80 km distance. The BER displayed significant improvement (less than 1.00E-09) with SRM at 80 km; however, without SRM and at 50 km, the BER is less than 1.00E-09. Investigations have presented an enhancement in the Q-factor’s effectiveness with the use of SRM, which helps to increase the XGPON length. When the length of the fibre is 80 km, the Q-factor is 6 with SRM, while it is 3.7 without SRM