Network on chip (NoC) is presented as a promising solution to face off the growing up of the data exchange in the multiprocessor system-on-chip (MPSoC). However, the traditional NoC faces two main problems: the bandwidth and the energy consumption. To face off these problems, a new technology in MPSoC, namely, optical network-on-chip (ONoC) has been introduced which it uses the optical communication to guaranty a high performance in communication between cores. In addition, wavelength division multiplexing (WDM) is exploited in ONoC to reach a high rate of bandwidth. Nevertheless, the transparency nature of the ONoC components induce crosstalk noise to the optical signals, which it has a direct effect to the signal-to-noise ratio (SNR) then decrease the performance of the ONoC. In this paper, we proposed a new system to control these impairments in the network in order to detect and monitor crosstalk noise in WDM-based ONoC. Furthermore, the crosstalk monitoring system is a distributed hardware system designed and test with the different optical components according the various network topology used in ONoC. The register-transfer level (RTL) hardware design and implementation of this system can result in high reliability, scalability and efficiency with running time less than 20 ms.
This paper proposed a new OFDM scheme called damped zero-pseudorandom noise orthogonal frequency division multiplexing (DZPN-OFDM) scheme. In the proposed scheme, ZPN-OFDM non-zero part is damped to reduce its energy, thus the mutual interference power in-between the data and training blocks with conservative the pseudo-noise conventional properties required for channel estimation or synchronization. The motivation of this paper is the OFDM long guard interval working in wide dispersion channels, whereas a significant energy is wasted when the conventional ZPN-OFDM is used as well as the BER performance is also degraded. Moreover, the proposed scheme doesn’t duplicate the guard interval to solve the ZPN-OFDM spectrum efficiency loss problem. Both detailed performance analysis and simulation results show that the proposed DZPNOFDM scheme can, indeed, offer significant bit error rate, spectrum efficiency and energy efficiency improvement.
The idea of adopting the space domain as the next frontier for optical communication has received increasing attention in the last few years. Optical devices are the integral parts of a mode division multiplexing (MDM) transmission. Therefore, conducting an intensive study on the devices is paramount to the successful realization of the overall system. This paper presents a review of the recent advances in the inline components of an MDM system, consisting of mode converters, spatial (de) multiplexers, optical amplifiers, and few-mode fibers (FMFs). Also presented are different mode conversion and multiplexing schemes. Recent techniques of minimizing differential mode gain (DMG) in the optical amplifiers are also reviewed. The review covers other types of amplification schemes and their current standing in the MDM system. These include optical semiconductor amplifiers (OSAs), and the Raman amplifiers (RAs). Finally, the review also highlights the role of FMF, multicore fiber and their relationship with fan-in/fan-out devices.
The large variability of communication properties of underwater acoustic channels, and especially the strongly varying instantaneous conditions in shallow waters, is a challenge for the designers of underwater acoustic communication (UAC) systems. The use of phase modulated signals does not allow reliable data transmission through such a tough communication channel. However, orthogonal frequency-division multiplexing (OFDM), being a multi-carrier amplitude and phase modulation technique applied successfully in the latest standards of wireless communications, gives the chance of reliable communication with an acceptable error rate. This paper describes communication tests conducted with the use of a laboratory model of an OFDM data transmission system in a shallow water environment in Wdzydze Lake.
Currently, production of wheat cultivars (Triticum aestivum L.) that show durable field resistance against fungal pathogens is a priority of many breeding programs. This type of resistance involves race-nonspecific mechanisms and can be identified at adult-plant stages. Until now, seven genes (Lr34/Yr18, Lr46/Yr29, Lr67/Yr46, Lr68, Lr75, Lr77 and Lr78) conferring durable types of resistance against multiple fungal pathogens have been identified in the wheat gene pool. In this study we showed a multiplex Polymerase Chain Reaction (multiplex PCR) assay, which was developed for detection of slow rusting resistance genes Lr34, Lr46, Lr68, using molecular markers: csLV34, Xwmc44 and csGS, respectively. Identification of molecular markers was performed on 40 selected wheat genotypes which are the sources of slow rusting genes according to literature reports. Multiplex PCR is an important tool to reduce the time and cost of analysis. This multiplex PCR protocol can be applicable for genotyping processes and marker assisted resistance breeding of wheat.
Multiple Input Multiple Output (MIMO (techniques use multiple antennas at both transmitter and receiver for increasing the channel reliability and enhancing the spectral efficiency of wireless communication system.MIMO Spatial Multiplexing (SM) is a technology that can increase the channel capacity without additional spectral resources. The implementation of MIMO detection techniques become a difficult mission as the computational complexity increases with the number of transmitting antenna and constellation size. So designing detection techniques that can recover transmitted signals from Spatial Multiplexing (SM) MIMO with reduced complexity and high performance is challenging. In this survey, the general model of MIMO communication system is presented in addition to multiple MIMO Spatial Multiplexing (SM) detection techniques. These detection techniques are divided into different categories, such as linear detection, Non-linear detection and tree-search detection. Detailed discussions on the advantages and disadvantages of each detection algorithm are introduced. Hardware implementation of Sphere Decoder (SD) algorithm using VHDL/FPGA is also presented.
To overcome the detrimental influence of α impulse noise in power line communication and the trap of scarce prior information in traditional noise suppression schemes , a power iteration based fast independent component analysis (PowerICA) based noise suppression scheme is designed in this paper. Firstly, the pseudo-observation signal is constructed by weighted processing so that single-channel blind separation model is transformed into the multi-channel observed model. Then the proposed blind separation algorithm is used to separate noise and source signals. Finally, the effectiveness of the proposed algorithm is verified by experiment simulation. Experiment results show that the proposed algorithm has better separation effect, more stable separation and less implementation time than that of FastICA algorithm, which also improves the real-time performance of communication signal processing.
In this paper we propose a method which allows to overcome the basic functional problems in holographic displays with naked eye observation caused by delivering too small images visible in narrow viewing angles. The solution is based on combining the spatiotemporal multiplexing method with a 4f optical system. It enables to increase an aperture of a holographic display and extend the angular visual field of view. The applicability of the modified display is evidenced by Wigner distribution analysis of holographic imaging with spatiotemporal multiplexing method and by the experiments performed at the display demonstrator.