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Evaluation of spectrally efficient indoor optical wireless transmission techniques

หน่วยงาน Edinburgh Research Archive, United Kingdom

รายละเอียด

ชื่อเรื่อง : Evaluation of spectrally efficient indoor optical wireless transmission techniques
นักวิจัย : Fath, Thilo Christian Martin
คำค้น : MIMO , Optical wireless communications , Optical wireless transmitter , Visual codes
หน่วยงาน : Edinburgh Research Archive, United Kingdom
ผู้ร่วมงาน : Haas, Harald , Thompson, John
ปีพิมพ์ : 2557
อ้างอิง : http://hdl.handle.net/1842/8894
ที่มา : -
ความเชี่ยวชาญ : -
ความสัมพันธ์ : T. Fath and H. Haas, “Performance Comparison of MIMO Techniques for Optical Wireless Communications in Indoor Environments,” IEEE Transactions on Communications, vol. 61, no. 2, pp. 733–742, Feb. 2013. , T. Fath, C. Heller, and H. Haas, “Optical Wireless Transmitter Employing Discrete Power Level Stepping,” IEEE/OSA Journal of Lightwave Technology, vol. 31, no. 11, pp. 1734–1743, Jun. 2013. , T. Fath, M. Di Renzo, and H. Haas, “On the Performance of Space Shift Keying for Optical Wireless Communications,” in Proc. of the IEEE Global Communications Conference - Workshop on Optical Wireless Communications, Miami, Florida, USA, Dec. 10, 2010, pp. 990–994. , T. Fath, H. Haas, M. Di Renzo, and R. Mesleh, “Spatial Modulation applied to Optical Wireless Communications in Indoor LOS Environments,” in Proc. of the IEEE Global Communications Conference, Houston, Texas, USA, Dec. 5–9, 2011, pp. 1–5. , T. Fath, J. Klaue, and H. Haas “Coded Spatial Modulation applied to Optical Wireless Communications in Indoor Environments,” in Proc. of the IEEE Wireless Communications and Networking Conference, Paris, France, Apr. 1–4, 2012, pp. 1000–1004. , T. Fath and H. Haas, “Optical Spatial Modulation using Colour LEDs,” in Proc. of the IEEE International Conference on Communications, Budapest, Hungary, Jun. 9–13, 2013, pp. 3938–3942. , F. Schubert, T. Fath, and H. Haas, “Coloured Video Code for In-Flight Data Transmission,” in Proc. of the International Conference on Computer Vision Systems, St. Petersburg, Russia, Jul. 16–18, 2013, pp. 42–51.
ขอบเขตของเนื้อหา : -
บทคัดย่อ/คำอธิบาย :

Optical wireless communications (OWC) has the potential to become a remedy for the shortage of the radio frequency (RF) spectrum. Especially in indoor environments, OWC could enable wireless home networking systems which offload data traffic from existing RF systems. In OWC, data is transmitted by modulating the intensity of light sources, typically incoherent light emitting diodes (LEDs). Thus, OWC systems employ intensity modulation (IM) and direct detection (DD) of the optical carrier. Since off-the-shelf LEDs have a limited modulation capability, the transmission bandwidth of practical OWC systems is restricted. Consequently, the available bandwidth has to be used efficiently. In this thesis, spectrally efficient optical wireless transmission techniques are evaluated. Firstly, multiple transmitter-receiver techniques are investigated. These multiple-input-multiple-output (MIMO) techniques provide high spectral efficiency, and therefore high data rates. Specifically, the MIMO techniques repetition coding (RC), spatial multiplexing (SMP) and spatial modulation (SM) are analysed for indoor OWC. The performance of these techniques is evaluated analytically and by means of computer simulations. It is shown that inducing power imbalance between the multiple optical transmitters can substantially improve the performance of optical MIMO techniques as the power imbalance improves the differentiability of the multiple channels. In addition, it is found that link blockage and the utilisation of transmitters having different optical wavelengths enhance channel differentiability as well. These methods enable the utilisation of optical MIMO techniques under conditions which typically disallow the application of MIMO schemes due to little differences between the multiple links. Secondly, a novel optical wireless transmitter concept is developed. This concept uses discrete power level stepping to generate intensity modulated optical signals, such as orthogonal frequency division multiplexing (OFDM) waveforms. The transmitter consists of several on-off-switchable LED groups which are individually controlled to emit scaled optical intensities. As a result, the digital-to-analogue conversion of the signals to be sent is done in the optical domain. This method enables the implementation of low-complex and power-efficient optical transmitter front-ends – the major shortcoming of conventional optical OFDM transmitters. Thirdly, a novel approach for wireless data transmission within an aircraft cabin is presented. The data is transferred by 2-dimensional visual code sequences. These sequences are displayed on the in-flight entertainment (IFE) screen and are captured by the built-in camera of a user device which acts as receiver. Transmission experiments within an aircraft cabin mock-up demonstrate the functionality of the implemented system under realistic conditions, such as ambient illumination and geometric configuration. Altogether, this thesis has analysed the potential of spectrally efficient optical wireless transmission techniques. It is shown that OWC systems can greatly benefit from these techniques.

บรรณานุกรม :
Fath, Thilo Christian Martin . (2557). Evaluation of spectrally efficient indoor optical wireless transmission techniques.
    กรุงเทพมหานคร : Edinburgh Research Archive, United Kingdom .
Fath, Thilo Christian Martin . 2557. "Evaluation of spectrally efficient indoor optical wireless transmission techniques".
    กรุงเทพมหานคร : Edinburgh Research Archive, United Kingdom .
Fath, Thilo Christian Martin . "Evaluation of spectrally efficient indoor optical wireless transmission techniques."
    กรุงเทพมหานคร : Edinburgh Research Archive, United Kingdom , 2557. Print.
Fath, Thilo Christian Martin . Evaluation of spectrally efficient indoor optical wireless transmission techniques. กรุงเทพมหานคร : Edinburgh Research Archive, United Kingdom ; 2557.