This paper assesses the performance of dual header pulse interval modulation (DH-PIM) over indoor optical wireless systems. DH-PIM being anisochronous scheme offers a built-in symbol synchronization capability. Theoretical and simulation results demonstrate that DH-PIM offers shorter symbol length, improved transmission rate and bandwidth requirement and a comparable power spectral density prof...

In this paper, a new method is proposed for image steganography that involves double encryption as well as compression of a message followed by its subsequent hiding in a digital image. The proposed method enhances bandwidth utilization besides ensuring three layered security to the message. The underlying principle of this method involves decomposition of each image-pixel into two blocks. One ...

The Peak to Average Power Ratio (PAPR) is currently viewed as an important implementation issue in communication systems. Specifically, for wireless cellular systems the price of the mobile unit is required to remain low. This means that a limited PAPR can be supported. Orthogonal Frequency Division Multiplexing (OFDM) and Single Carrier (SC) are the prominent candidates for the next generation...

The WiMAX technology support to different channel bandwidth, cyclic prefix, modulation coding scheme, frame duration, simultaneous two way data transfer and propagation model. The WiMAX network asymmetry is largely depends on DL: UL ratio. This paper evaluate the performance of TCP Sack1 by considering Channel Bandwidth, Cyclic Prefix, Modulation Coding Scheme, Frame Duration, Two way transfer ...

Graphene has emerged as an ultrafast photonic material for on-chip all-optical modulation. However, its atomic thickness limits interaction with guided optical modes, which results in a high switching energy per bit or low modulation efficiencies. Nonetheless, it is possible to enhance the of light graphene by nanophotonic means. Herein, we present practical design modulator that based on and h...

In recent years, various chaos based modulation schemes were evolved, of which the CS-DCSK modulation technique provides a better BER performance and bandwidth efficiency, due to its code domain approach[10]. The QCSK modulation technique provides double benefit, namely: higher data rate with similar BER performance and same bandwidth occupation as DCSK. By combining the advantage of code shift...

This paper proposes a new modulation for a Global Navigation Satellite System (GNSS) to efficiently utilize a given bandwidth. This modulation, referred to as Time-Multiplexed Multi-Carrier (TMMC), divides the available bandwidth into N sub-bands such that each sub-band resembles a Quadrature Phase Shift Keying (QPSK) modulation and at the same time allows the receiver to exploit the benefits o...

Orthogonal transmitter diversity such as frequency diversity and time diversity is quite simple to implement and, with optimum signal combining, can take full advantage of fading multipath channels. However, such a scheme has a bandwidth efficiency that decreases inversely with the number of diversity branches making it less attractive in wireless communications applications. This paper conside...

Abstract A flexible full-color micro-LED display with high mechanical robustness was fabricated by printing quantum dots (QDs) on a blue array using standard photolithography. The red and green colors yielded from QDs exhibit better color gamut than conventional filters. light conversion efficiency enhanced adding TiO 2 nanoparticles to the QD-photoresist composite. This successfully mounted va...