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

For high data rate propagation and indoor obstacles in wireless ultra-wideband (UWB) communication systems, the signal fading and noises are influencing the performance of the wireless systems. In this paper, the rake-receiver was presented with the spread signal by time-hopping spread spectrum (TH-SS) technique. The adaptive filter used in rake-receiver structure was shown with adjusting the receiver tap weights using Euclidean Direction Search (EDS) algorithm to support the weak signals by noise cancellation. To minimize the data convergence speed and to reduce the computational complexity by the previous algorithms, a well-known approach of selective-updates (SU) adaptive filter was employed with algorithms, such as sequential-selective, periodic-selective, and M-max-selective in the proposed system. The simulation results of bit error rate (BER) versus signal-to-noise ratio (SNR) are illustrated to show the performance of selective-update algorithm that has nearly comparable performance with the full update adaptive filters.

Selective update euclidean direction search algorithm for adaptive filtering in indoor wireless rake-receiver

Abstract In this paper, the performance of a hybrid scheme of Subcarrier Multiplexing (SCM) technique in a Spectral Amplitude Coding (SAC) Optical Code Division Multiple Access (CDMA) transmissions system is evaluated. The hybrid system is design using new code family; we call it Dynamic Cyclic Shift (DCS) code. The DCS code design for SAC-OCDMA system to reduce the effect of Multi Access Interference due to it property of low cross-correlation (λC ≤ 1) between code words. In contrast, the SCM scheme shows the ability to increase the data rate of SAC-OCDMA system. Consequently, the hybrid SCM/SAC-OCDMA system could be one promising solution to the high-capacity access network with low cost effective, good flexibility and enhanced security, which makes an attractive candidate for next-generation broadband access network.

Performance Evaluation of Hybrid SCM/SAC-OCDMA Transmissions System using Dynamic Cyclic Shift Code

This paper focus on increase the efficiency power in free space optical communication by using new dual diffuser modulation (DDM) technique. Atmospheric turbulence effect which is considering on scintillation phenomenon is considered in this case study. Phase screen diffuser which will be placed at transmitter create ‘new’ beam wave to propagate through turbulence more efficiently. This technique uses two transmitter and differential mode detection at the receiver. The result shows that at 622Mbps data bit rate the DDM technique can detect more weak signal approximately −15dBm and with assume fix propagation distance at 1km the power received can achieved −26dBm. As the result, DDM technique improved the efficiency power if compare to conventional technique that apply intensity modulation — direct detection of On Off Keying (IM-DD OOK).

Efficiency power using a new dual diffuser modulation technique in free space optical communication

A new code of optical code division multiple access (OCDMA) based on Spectral Amplitude Coding (SAC) is described and analyzed. The coding technique is called Random Diagonal “RD” code. One of the important properties of this code is that the cross correlation at data segment is always zero, which means that Phase Intensity Induced Noise (PIIN) is reduced. From the construction of RD code sequence, we can see that the RD code is constructed using code segment and data segment. Using this code property, RD code is implemented using coherent source (multilaser) and incoherent source (light emitting diode) for the code segment and data segment respectively. RD code using two multi-sources (inchoherent and coherent) can be considered as an effective way for maximizing the capacity while minimizing the cost of SAC-OCDMA. It is shown that the system using this new code matrices not only suppresses PIIN, but also allows a larger number of active users compared with other codes.

New Code Structures Based on Coherent and Incoherent Sources for Spectral Amplitude Coding-OCDMA Systems

In this paper we study the use of a new code called Random Diagonal (RD) code for Spectral Amplitude Coding (SAC) optical Code Division Multiple Access (CDMA) networks, RD code is constructed using code level and data level, one of the important properties of this code is that the cross correlation at data level is always zero, which means that Phase intensity Induced Phase (PIIN) is reduced. We find that the performance of the RD code will be better than Modified Frequency Hopping (MFH) and Hadamard code It has been observed through experimental and theoretical simulation that BER for RD code perform significantly better than other codes. Proof -of-principle simulations of encoding with 3 channels, and 10 Gbit/s data transmission have been successfully demonstrated together with Fiber Bragg grating (FBG) decoding scheme for canceling the code level from SAC-signal.

Hilal A. Fadhil

Papers

Selective update euclidean direction search algorithm for adaptive filtering in indoor wireless rake-receiver

Performance Evaluation of Hybrid SCM/SAC-OCDMA Transmissions System using Dynamic Cyclic Shift Code

Efficiency power using a new dual diffuser modulation technique in free space optical communication

New Code Structures Based on Coherent and Incoherent Sources for Spectral Amplitude Coding-OCDMA Systems

Design of Spectral Amplitude Coding Optical Code-division Multiple-access System using Random Diagonal Codes