in scpc-dama satellite networks, the baseband rrc pulse shaping is utilized to reduce the bandwidth and inter symbol interference (isi). but the variation in carrier's envelope, which expands the spectrum and ultimately increases the bandwidth, causes isi and quadrature channel crosstalk (qcc). the goal of this paper is to introduce a method to shape baseband rrc pulses, in order to make a near...

The modulation response, relative intensity noise (RIN) and frequency noise (FN) characteristics of quantum dot (QD) lasers are investigated theoretically in the presence of an external optical beam. Using small signal analysis of the rate equations for carriers and photons, it is demonstrated that by injecting excess carriers into the QDs excited state through optical pumping, the modulation r...

Due to the growing demand for higher bandwidth, employing optical devices instead of electronic devices in data transmission systems has attracted much attention in recent years. Optical switches, modulators and wavelength converters are a few examples of the required optical devices. CMOS compatible fabrication of these devices, leads to much more growing of this technology. Optical pulse comp...

The light emitting diode (LED) nonlinearities distortion induced degradation in the performance of visible light communication (VLC) systems can be controlled by optimizing the DC bias point of the LED. In this paper, we theoretically analyze and experimentally demonstrate the effect of white LED DC bias on nonlinear modulation bandwidth and dynamic range of the VLC system. The linear dynamic r...

The recent proliferation of terrestrial and space-based communication systems has given rise to an increasingly critical problem—the lack of available frequency spectrum. One tool that satellite system designers can use to maximize the use of available spectrum is bandwidth-efficient modulation. This technique can enhance bandwidth efficiency while retaining reasonable power efficiency and impl...

Last years, Wavelet Packet Modulation (WPM) or Wavelet Packet Transform based Orthogonal Frequency Division Multiplexing (WPT-OFDM) have been introduced to wired and wireless communication fields as efficient Multicarrier Modulation (MCM) techniques. The wavelets have interesting features such as flexibility, compatibility and localization in both time and frequency domains with no need to use ...

One of the dramatic developments in bandwidth-efficient communications over the past few years is the introduction and rapid applications of combined coding and bandwidth efficient modulation, known as coded modulation, for error control. Using coded modulation, reliable data transmission can be attained without compromising bandwidth efficiency. In this report, we present the basic concepts of...