Normal hearing persons are able to localize the direction of sounds better using both ears than when
listening with only one ear. Localization ability is dependent on auditory system perception of
interaural differences in time, intensity, and phase. Interaural timing differences (ITDs) provide
information for locating direction of low and mid frequency sounds, while interaural level differences
(ILDs), which occur because of the horizontal plane shadowing effect of the head, provide information
for locating direction of higher frequency sounds. The head related transfer function (HRTF) contains
characteristic information important for acoustic localization. Models based on HRTFs take into
account head shadow, torso, and pinna effects, and their impact on interaural frequency, level, and
Cochlear implants (CIs) have proven a successful treatment for persons with bilateral severe to
profound hearing loss. A problem is that only some ITD and ILD cues are maintained with CI sound
processing, and the microphone position alters the acoustic cues. The relative impact of differences in
physical cues received by the auditory system with bilateral CIs versus differences in the ability of the
damaged auditory nervous system to process bilateral inputs is not yet clear. The model presented in
this paper was constructed as a step toward answering this question, and is intended to serve as a tool
for future development of more optimal signal processing algorithms that may provide better
localization ability for persons with bilateral CIs.
Orthogonal Frequency Division Multiplex (OFDM) is a modulation technique to transmit the baseband Radio signals
over Fiber (RoF). Combining OFDM modulation technique and radio over fiber technology will improve future wireless
communication. This technique can be implemented using laser and photodetector as optical modulator and
demodulator. OFDM uses multiple sub-carriers to transmit low data rate streams in parallel, by using Quadrature
Amplitude Modulation (QAM) or Phase Shift Keying (PSK). In this paper we will compare power spectrum signal and
signal constellation of transmitted and received signals in RoF using Matlab and OptiSystem simulation software.
Proc. SPIE. 7797, Optics and Photonics for Information Processing IV
KEYWORDS: Signal to noise ratio, Transmitters, Receivers, Telecommunications, Antennas, Wireless communications, Data communications, Orthogonal frequency division multiplexing, Signal detection, Mobile communications
By increasing multimedia communications, mobile communications are expected to reliably support high data rate
transmissions. To provide higher peak rate at a better system efficiency, which is necessary to support broadband data
services over Wireless links, we need to employ long term evolution Advanced (LTE-A) Multiple-input multiple-output
MIMO uplink. The outline of this paper is to investigate and discuss the Long Term Evolution (LTE) for broadband
wireless technologies and to discuss its functionality. We explore how LTE uses the inter-technology mobility to support
a variety of access technology.
This paper investigates the channel capacity and bit error rate of MIMO-OFDM system. In addition, it introduces various
MIMO technologies employed in LTE and provide a brief overview on the MIMO technologies currently discussed in
the LTE-Advanced forum.
Tunable semiconductor laser has various applications including Wavelength Division Multiplexing (WDM), Frequency Division Multiplexing (FDM), optical switching in Local Area Networks (LAN) and Chemical Sensing, or Spectroscopy. There are different approaches for tunable semiconductor lasers. Large wavelength tuning range is required for communication applications, such as WDM. Whereas a frequency modulation (FM) requires small but fast frequency shifts. Two-Segment laser is one of the methods to realize continuous
optical tuning. The device consists of two coupled cavities having a series of well-defined modes. The modes are equally spaced within a cavity but the mode spacing between the two cavities is slightly different. Characterization results of such lasers are very important. In this paper we will present the characterization
results of two segment InGaAs/InP distributed feed back (DFB) tunable lasers.