This paper proposes an analytical model for evaluating the performance of dense wavelength division multiplexing (DWDM) for all optical orthogonal frequency division multiplexing (AO-OFDM) optical wireless channel. The investigated performance for proposed system is evaluated for the parameters bit error rate (BER) and Q factor. The constellation diagrams, and bit error rate (BER) of the received signals are specified. The effect of atmospheric attenuation of the outdoor wireless optical communication system was induced (channel impairments) such as medium rain, light rain, and dust to find their effects on system performance carrier wavelength. The results show the BER and constellation diagram under different weather conditions for different transmission distance using Quadrature Amplitude Modulation (QAM) AO-OFDM-optical wireless channel (OWC).

In the present paper, a 16-channel implantable wireless neural recording system is presented. The proposed system employs frequency-division multiplexing (FDM) to transfer multiple neural channels to an external setup wirelessly. The main advantage of the proposed system is that, while increasing the number of channels, it efficiently utilizes the limited bandwidth allocated for wireless data transmission such as the 402-405 MHz, 174-216 MHz, or 88-108 MHz bands allocated for medical implant communication services. In this system, neural activities from multiple channels are detected using two-dimensional or three-dimensional microelectrodes. After preconditioning, the multiple parallel channels are multiplexed in the frequency domain within the FDM module. As a result of FDM, preconditioned neural signals are placed in the frequency domain with 100kHz spacing, occupying a 1600kHz bandwidth starting from 10MHz. Finally, the resulting FDM band is shifted in the frequency domain by the frequency modulation (FM) block with a carrier frequency of 100 MHz. A 16-channel prototype system is designed and simulated using 0.18 µm CMOS technology, with a chip area of 0.55 × 0.58 mm²and a power consumption of 3.35 mW at a supply voltage of 1.8V.

For the most relay networks with fading channels, it is practicable to devise communication schemes that are optimal in terms of diversity multiplexing trade-off (DMT). Characterizing the DMT of a general n-relay is an ongoing challenging problem. In this paper, we show that to compute DMT of a diamond relay channel one has to solve an optimization problem. Direct computation of DMT of a diamond network with n relays requires solving 2n optimization problems (an optimization for each cut in the network). Solving that many optimization problems in networks with many relays is not practical. We demonstrate that for any n -relay full-duplex diamond channel, if all the exponential orders of the average signal to ratios of links in the network are greater than the multiplexing gain, then computing DMT of such network is equivalent to minimizing a sub modular function and can be carried out in polynomial time.

This paper presents an empirical mode decomposition (EMD) based adaptive filter (AF) for channel estimation in OFDM system. In this method, length of channel impulse response (CIR) is first approximated using Akaike information criterion (AIC). Then, CIR is estimated using adaptive filter with EMD decomposed IMF of the received OFDM symbol. The correlation and kurtosis measures are used to select the useful IMF component from among available IMFs. Conventional AF uses random initial weight vector. The novelty of the proposed method is that it uses decimated version of one of the decomposed IMFs of received OFDM symbol as initial weight vector. This makes the proposed EMD based AF method converge to minimum mean square error (MMSE) in less number of iterations resulting in almost 50% saving of computations. The simulation studies in terms of bit error rate (BER) and mean square error (MSE) calculations established the efficacy of proposed method; and comparative studies under different modulation schemes and fading conditions revealed improved performance.

The signal integrity problem, especially crosstalk noise, is an important issue in physical design in the nanometer regime. Wire multiplexing is a recently proposed method to reduce these problems in current design methodologies. This technique is presented to increase the routability of the design and also reduce crosstalk noise by serializing parallel wires via delay insensitive asynchronous serial transceivers. In this paper, this technique is improved in terms of routability and computation time and, also, its impact on crosstalk is examined. Finally, it is evaluated with 180 nm and 130 nm technologies. Experimental results show that for the attempted benchmarks, congestion and routability are improved by 15.54% and 21.57% on average, respectively, and crosstalk noise is improved by 9.51% on average. These improvements are achieved at the cost of a slight increase in power consumption (0.12% on average) and runtime (less than 10.01% on average).

Due to the increase of users the efficient usage of spectrum plays an important role in digital terrestrial television networks. In digital video broadcasting, local and global content are transmitted by single frequency network and multifrequency network respectively. Multifrequency network support transmission of global content and it consumes large spectrum. Similarly local content are well supported by single frequency network. In order to provide better spectral efficiency both local and global contents are transmitted in single constellation using hierarchical modulation. Hierarchical modulated OFDM system provides good spectral efficiency and robustness to the fading environment. In this paper a hierarchical modulated OFDM system for local service insertion is analyzed and its performance under various channels is been discussed. Convolutional encoder is used in this paper.

Channel estimation is a crucial task for orthogonal frequency division multiplexing (OFDM) modulation-based systems since this estimation is used for compensating impacts of a wireless channel. Recently, sparse representation (SR) is proposed for this task as wireless channels are considered as a sparse signal. However, SR considers sparse as the main feature and omit other features of the channel while estimating the channel. In this paper, we propose a general framework for utilizing other features of the channel in sparse channel estimation for OFDM systems, while these features are omitted in conventional sparse methods. In this regard, by utilizing maximum a posterior (MAP) estimation and defining new parameters, these features are conveyed into sparse channel estimation process to improve channel estimation. The simulation results indicate that our proposed framework not only improves the estimated parameter, but also reduces the number of resources such as the number of estimation pilots or transmitted power.

Objective: Breast cancer is multidimensional disease in initiating trends inflicting almost every aspect of cell cycle. Metastasis (chain of non-randomized sets of events) is usually influenced by abnormal inflictions induced either at genetic or epigenetic levels. Current objective of this study is to identify and characterize sets of those molecules which are found responsible for suppression of metastasis cascade. Our earlier research highlighted the putative role of CD82 (a tetraspanin family member) in suppression of breast cancer metastasis progression. A central dogma based analysis of this molecule (germline mutation and expression screening) in breast cancer affected patients highlighted its potential significance in disease progression as well as overall patient’s survival (p=0.04) For a thorough insight, effect of this molecule on cancer cells proliferation, adhesion, motility and invasion had also been studied. Materials and Methods: Transgenes based cancer cell lines (both forced expression in MCF-7 as well as knock out in MDA-MB-231) were generated. Results: After extensive experimentation, a significant correlation of CD82 along with cancer cell adhesion (p=0.021), cellular invasion (p=0.022) and motility (p=0.024). CD82 did not impart any significant role on cancer cells growth.Conclusion: From this data it has been evidential CD82 substantially contribute to cancer cells regulation in metastatic cascade. Another elucidated sphere of this study is to extract and characterize such sets of molecules that impart a substantial role in this metastasis process in relation to breast cancer. Identifying and multiplexing those markers along with their potential role will help in designing a tool for early prognosis. Metastasis suppressor genes may be also be set a universal set of marker for tracking metastasis initiation, promotion and progression.