172 research outputs found
Introduction to Random Signals and Noise
Random signals and noise are present in many engineering systems and networks. Signal processing techniques allow engineers to distinguish between useful signals in audio, video or communication equipment, and interference, which disturbs the desired signal. With a strong mathematical grounding, this text provides a clear introduction to the fundamentals of stochastic processes and their practical applications to random signals and noise. With worked examples, problems, and detailed appendices, Introduction to Random Signals and Noise gives the reader the knowledge to design optimum systems for effectively coping with unwanted signals.\ud
\ud
Key features:\ud
⢠Considers a wide range of signals and noise, including analogue, discrete-time and bandpass signals in both time and frequency domains.\ud
⢠Analyses the basics of digital signal detection using matched filtering, signal space representation and correlation receiver.\ud
⢠Examines optimal filtering methods and their consequences.\ud
⢠Presents a detailed discussion of the topic of Poisson processed and shot noise.\u
Provision of metro ethernet services using a reconfigurable photonic access network
The paper proposes a design for traffic engineering to provide Ethernet services using an extended access network. Ethernet has remained the dominant technology for Local Area and Enterprise Networks, the use of Ethernet in metro networks has seen significant interest of late to provide for end to end Ethernet services to the user. The Broadband Photonic (BBP) access network is viewed as a quasi independent stack of EPONs in which geographically spread customer-VLANs (C-VLANs) can be implemented. The use of such a network for providing metro Ethernet like services in addition to traditional access services is presented
An ultra fast optical header replacement technology and its application for broadband optical packet switch.
An optical header replacement technology based on Self Electro-optic Effect Devices (SEEDs) is presented. By using the measurement result of a 75 Îźm long SEED device, we simulate an 8 Gbps throughput is achievable. Based on the switching characteristics of SEEDs, we proposed several methods to improve the SEEDs switching speed. An ultra fast switching speed at 50 Gbps is achievable by integrating external components and applying a pair of preset pulses. Due to the convenience of operation in both the optical domain and the electrical domain, it is very suitable for optical header processing; therefore it is an ideal candidate solution for optical fast packet switch
Performance comparison of the cascaded MZI based OCDMA system using multimode and singlemode fibers
New Ethernet Based Optically Transparent Network for Fiber-to-the-Desk Application
We present a new optical local area network architecture based on multimode optical fibers and components, short wavelength lasers and detectors and the widely used fast Ethernet protocol. The presented optically transparent network represent a novel approach in fiber-to-the-desk applications. It is made to minimize the costs associated with a passive optical LAN implementation. The biggest issues in the realization of the network are the synchronization of bursty traffic and collision detection. We present, in detail, the solution to the synchronization problem by introducing an analog sinusoidal carrier that is in addition to the data signal only sent within the data packet duration. The extraction of data and the synchronization signal is made by using simple filtering, facilitating the receiver realization
Push-pull modulated analog photonic link with enhanced sfdr
We demonstrate an analog photonic link (APL) with a high multioctave spurious-free dynamic range (SFDR) of 120 dB.Hz2/3 at the frequency of 2.50 GHz. The APL consists of a pair of distributed-feedback laser diodes (DFB LDs), modulated in a push-pull manner, and a balanced photodetector aiming at suppressing the second-order intermodulation distortion (IMD2). At the frequency of 2.50 GHz, an IMD2 suppression of 40 dB, relative to the case of a single arm APL with one laser, is obtained. In a wide frequency range of 600 MHz (2.60 to 3.20 GHz), an improvement of 5 to 18 dB of the second-order SFDR relative to the single arm APL has been achieved.\ud
\u
Enhanced dynamic range in a directly modulated analog photonic link
We demonstrate a directly modulated analog photonic link (APL) capable of a high multioctave spurious-free dynamic range (SFDR). The APL consists of a pair of laser diodes, modulated in a pushâpull manner, and a balanced photodetector aiming at suppressing the second-order intermodulation distortion (IMD2). In a wide frequency range of 600 MHz (2.60â3.20 GHz), an IMD2 suppression as high as 23 dB and an improvement of 5â18 dB of the second-order SFDR, relative to a conventional single arm photonic link, have been achieved. In this frequency range, the APL SFDR is in excess of 116 dB.Hz2/3}
Traffic control in coherence-multiplexed networks
Coherence multiplexing (CM) is a relatively unknown form of optical CDMA, which is particulary suitable in medium bit rate, short-range optical networks like LANs. The main purpose of the technique is to allow multiple users to transmit through a common optical fiber simultaneously. When this number is too large, however, the BER will become unacceptably high. Therefore a protocol is needed to control the traffic. In this paper several protocols are presented. An adapted version of synchronous TDMA, two new protocols and a central control unit will be proposed and discussed. Finally, the protocols will be compared with respect to performance and practical implementation aspects
Coherence-Multiplexed Optical RF Feeder Networks
An optical RF feeding system for wireless access is proposed, in which the radio access points are distinguished by means of coherence multiplexing (CM). CM is a rather unknown and potentially inexpensive optical code division multiple access technique, which is particularly suitable for relatively short-range applications with moderate transmission bandwidth requirements. Subcarrier multiplexing (SCM) can possibly be used on top of CM, either as single-channel or multichannel SCM. The performances of the resulting distribution networks are analyzed, incorporating the effect of chromatic dispersion, optical beat noise, shot noise, thermal noise, andâin the case of multichannel SCMâintermodulation distortion. The results of the IEEE 802.11b standard for wireless LAN.\u
- âŚ