There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Course Description This is an advanced course in which we explore the field of Statistical Optics. Topics covered include such subjects as the statistical properties of natural (thermal) and laser light, spatial and temporal coherence, effects of partial coherence on optical imaging instruments, effects on imaging due to randomly inhomogeneous media, and a statistical treatment of the detection of light. Development of this more comprehensive model of the behavior of light draws upon the use of tools traditionally available to the electrical engineer, such as linear system theory and the theory of stochastic processes.

http://ieeexplore.ieee.org/iel5/3/23094/01073023.pdf

Statistical optics

Several simplified design procedures for solar energy systems require monthly average meteorological data. Monthly average daily totals of the solar radiation incident on a horizontal surface are available. However, radiation data on tilted surfaces, required by the design procedures, are generally not available. A simple method of estimating the average daily radiation for each calendar month on surfaces facing directly towards the equator has been presented by Liu and Jordan [1]. This method is verified with experimental measurements and extended to allow calculation of monthly average radiation on surfaces of a wide range of orientations.

Calculation of monthly average insolation on tilted surfaces

In general, Micropower Impulse Radar (MIR) depends on Ultra-Wideband (UWB) transmission systems. UWB technology can supply innovative new systems and products that have an obvious value for radar and communications uses. Important applications include bridge-deck inspection systems, ground penetrating radar, mine detection, and precise distance resolution for such things as liquid level measurement. Most of these UWB inspection and measurement methods have some unique qualities, which need to be pursued. Therefore, in considering changes to Part 15 the FCC needs to take into account the unique features of UWB technology. MIR is applicable to two general types of UWB systems: radar systems and communications systems. Currently LLNL and its licensees are focusing on radar or radar type systems. LLNL is evaluating MIR for specialized communication systems. MIR is a relatively low power technology. Therefore, MIR systems seem to have a low potential for causing harmful interference to other users of the spectrum since the transmitted signal is spread over a wide bandwidth, which results in a relatively low spectral power density.

/pdf/response-to-fcc-98-208-notice-of-inquiry-in-the-matter-of-3attixctl7.pdf

Response to FCC 98-208 notice of inquiry in the matter of revision of part 15 of the commission's rules regarding ultra-wideband transmission systems

Ultra Wideband Signals and Systems in Communication Engineering

A new code for Spectral Amplitude Coding - Optical Code Division Multiple Access (SAC-OCDMA) is proposed and is called Flexible Cross-correlation (FCC) code. The FCC code possesses various advantages; including easy code construction using Tridiagonal matrix compared to other SAC-OCDMA codes such as MDW, MQC and MFH, shorter code length and the important properties of this code is the flexible cross-correlation. Our results reveal that FCC code can effectively alleviated Phase Induced Intensity Noise (PIIN) and allows large cardinality and improve the bit error rate performance.

/pdf/alleviation-noise-effect-using-flexible-cross-correlation-2vduap8h3c.pdf

Alleviation Noise Effect Using Flexible Cross Correlation Code in Spectral Amplitude Coding Optical Code Division Multiple Access Systems

In this study, the spectral efficiency (SE) of bipolar spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) systems operating with incoherent sources is analysed. The analytical expressions of the model were derived to assess the performance of SAC-OCDMA systems, taking into account the intensity noise as the primary source of noise. Four different SAC codes were used to evaluate and compare the SE against the number of active users and code length for a bit-error rate (BER) of 10−11. The investigated codes are Hadamard, modified quadratic congruence (MQC), balanced incomplete block design (BIBD) and zero cross-correlation (ZCC). Our analytical results revealed that ZCC code has the ability to support more users at a high data rate up to 2.5 Gbps and offers significant SE enhancement in bipolar SAC-OCDMA system over other SAC codes under investigation. In addition, bipolar encoding improves the SE compared with unipolar technique, for example bipolar ZCC has 7.7-dB SE advantage than unipolar ZCC. Furthermore, when BER requirement of the system decreases, the SE can be increased.

Spectral efficiency analysis of bipolar spectralamplitude coding optical code-division multipleaccess systems using different one-dimensional codes

The development of many high bit-rate multimedia applications has emphasized the demand for service differentiation or prioritization techniques to ensure end-user quality-of-service (QoS) necessities. This paper focuses on utilizing different detection schemes in spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) systems to support ‘triple-play’ services (voice, video, and data) with diverse QoS requirements. The used subtraction detection techniques are complementary, AND, as well as modified-AND. Modified double-weight (MDW) codes are used as the signature codes for SAC-OCDMA systems. The simulation results show that modified-AND subtraction detection demonstrates better performance over other detection approaches.

Triple-play services using different detection techniques for SAC-OCDMA systems

Recently, extensive requirements have developed for ultra-wideband (UWB) technology that provides high activity and small size for use in small communication systems, remote sensing, and radar applications. Thus, we concentrated with high-resolution radar UWB antenna to cover Federal Communication Commission’s (FCC) standard UWB range (3.1-10.6 GHz). The proposed ideal-size and low-cost finger-shaped patch antenna of 24 mm x 19 mm printed on 40 mm x 35 mm rectangular Taconic TLY-5 material was designed and established through experiments and simulations. Results show that the two cut notches of 1.5 mm x 2 mm at the bottom corners of the patch can increase the bandwidth. To increase the radiation area and achieve more resonance frequencies, two cut slots at the top edge of the patch were designed in depth of 10 mm. Four parameters were considered in the analysis of the proposed antenna design, namely the feeder width, number of slots, number of notches, and feed gap space. The simulated and measured results of the main antenna parameters make the design suitable in applications of UWB wireless systems.

Planar Finger-Shaped Antenna Used in Ultra-Wideband Wireless Systems

This paper proposes a new approach that utilizes Free Space Optics (FSO) in hybrid SCM-SAC-OCDMA system. Among the numerous properties of this approach, the most important is a reduction of the multi access interference (MAI) and the overcoming of the overlapped wavelengths. Simplicity, cost-effectiveness, and free license with (MD) code have made this approach a compelling candidate for Last Mile Communications. This paper proposes the hybrid system for Free Space Optic (FSO) and also shows the effect of rain attenuation on this proposed system. The study is made according to the Malaysian weather conditions (Kuala Lumpur) through simulation. The simulation results proved that the MD code hybrid system produces less Bit-Error Rate (BER) at storm rain up to 500 m range. In addition to that the data rate is set to 1 Gb/s and power 6 dBm.

Hilal A. Fadhil

Papers

Alleviation Noise Effect Using Flexible Cross Correlation Code in Spectral Amplitude Coding Optical Code Division Multiple Access Systems

Spectral efficiency analysis of bipolar spectralamplitude coding optical code-division multipleaccess systems using different one-dimensional codes

Triple-play services using different detection techniques for SAC-OCDMA systems

Planar Finger-Shaped Antenna Used in Ultra-Wideband Wireless Systems

A study on rain attenuation impact on hybrid SCM-SAC OCDMA-FSO system