Physical layer network coding (PNC) for a two-way relay (TWR) channel has been utilized for increasing the system
throughput in a TWR, where the two users exchange their information via a relay node. PNC with a TWR channel is
adopted free space optical (FSO) communication link (TWR-FSO) to enhance the link availability under the atmospheric
turbulence condition. FSO has attracted significant attention in a range of application, where the radio frequency (RF) based
wireless technologies may not be used or be suitable. In fact, the use of FSO in certain applications releases the pressure on
already highly congested RF spectrum, which can be used in areas where the demand for RF is very high. In this research,
we introduce the turbo code in the TWR-FSO PNC system and evaluate the end-to-end (E2E) in terms of the bit error rate
(BER) for weak and strong regimes. The performance of E2E turbo code in terms of iterative manner combined with TWRFSO
PNC is presented to improve the system performance and then compared with both non-iterative convolutional code
and uncoded systems under the different influences turbulence. The simulation results shows that the proposed scheme can
achieve a significant BER performance improvement through the introduction of an iterative process between turbo decoders.
Furthermore, we investigate the decoding process of the system by using a graphical description, this involved implementing
the extrinsic information transfer (ExIT) charts. The ExIT chart was implemented as a tool to analyze the convergence
properties of iterative receivers. We review the ExIT chart, the simulation setup and the construction to analyze the major
features of system architecture. The ExIT functions of the two decoders are thoroughly analyzed for a range of parameters
under the influence of a turbulence-induced channel fading to demonstrate the convergence behavior.
Alaa A Saeed Al Rubaie has completed his PhD in Communications from Communications, Sensors, Signal and Information Processing (ComS2IP) Group, School of Electrical and Electronic Engineering, Newcastle University, Newcastle Upon Tyne, UK He has MSc in Computer Network from University of Technology, Baghdad, Iraq. He is currently working as the Director in the Department of Information Technology in the Ministry of Higher Education and Scientific Research, Baghdad, Iraq. He has his expertise in wireless communication networks with a focus on an advanced modulation, coding technique, equalization, radio frequency and free-space optical channels.
Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals