IEEE 802.16 Metropolitan Area Network with SDMA Enhancement
Authors: Hoymann, Christian
Department of Communication Networks (ComNets), Faculty 6, RWTH Aachen University
Contact: publications@comnets.rwth-aachen.de
Ph. D. Dissertation Aachen University, p. 269, ISBN:3-86130-936-X,Wissenschaftsverlag Mainz, 2008.
Publication Date: Jul, 2008
On page(s):269
ISBN: 3-86130-936-X
Abstract Broadband access is the key driver of the telecommunications industry today. Customers all around the world demand this service to surf the World Wide Web (WWW) and to communicate by email. Furthermore, the classical Internet undergoes a shift towards a collaborative (second generation) Internet of people. The WWW is used as a platform to establish social networks and to share self-generated content. People download and upload rich multimedia content. They want to be connected. In metropolitan areas, fixed Broadband Wireless Access (BWA) offers a costeffective alternative to wired broadband access technology such as Digital Subscriber Line (DSL) and cable modem. In rural areas, fixed BWA can bridge the digital divide by bringing broadband services to remote places. Finally, BWA technology provides market potential for portable and mobile broadband services. IEEE 802.16 (or WiMAX) is a promising radio access technology that performs similar to wired access systems and covers large geographic regions. The key feature to reach that goal is the integration of multi antenna techniques. Beamforming is the most promising MIMO technique since it allows for both, increased system capacity and extended cell coverage. The thesis describes the developed comprehensive system concept to fully integrate Space Division Multiple Access (SDMA) technology into the IEEE 802.16 system. SDMA affects a large portion of the WiMAX system. Multiple antennas are required in the PHY layer to form adaptive patterns. Through the newly specified PHY Service Access Point (SAP) the enhanced PHY layer offers its beamforming services to the Medium Access Control (MAC) entities. The extended MAC protocol controls the additional spatial dimension. Multiple access based on Time Division Multiple Access (TDMA) and SDMA need to be coordinated. Besides the protocol, MAC algorithms are affected by beamforming and SDMA. The hierarchical TD-SD-OFDM scheduling algorithm proposed in this work optimizes resource allocation while observing strict real-time constraints. For multi-hop transmission a MAC extension is specified and evaluated. By leveraging SDMA on the feeder link, the proposed MAC frame structure strengthens the radio link, which is the bottleneck in most multi-hop systems. On the access link, interference suppression by means of beamforming allows for a tight spatial reuse of the radio resource in Relay Station (RS) controlled subcells. The introduced analytical evaluation illustrates the upper bounds of an OFDM-based IEEE 802.16 system in terms of coverage and throughput. It compares single-hop and multi-hop scenarios and illustrates the benefits of multi-hop operation. Furthermore, the thesis shows a possible implementation of an SDMA-enabled IEEE 802.16 system. Especially the prototypical TD-SD-OFDM scheduler can be seen as an exemplary reference implementation. The implementation is embedded in the event-driven system level simulator Wireless Network Simulator (WNS). The WNS is an open source simulation framework that is publicly available. The simulation tool comprises all aspects of the system, which are affected by SDMA. The presented simulative performance evaluation shows the enormous potential of beamforming and SDMA technologies. The thesis illustrates the enhanced throughput, the reduced packet delay, and the extended coverage of the SDMA-enabled WiMAX system. The major parameters that influence the system behavior are identified and evaluated.
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@PHDTHESIS{DISS_Hoymann_2008,
AUTHOR = {Hoymann, C.},
TITLE = {IEEE 802.16 Metropolitan Area Network with SDMA Enhancement},
YEAR = {2008},
MONTH = {Jul},
VOLUME = {57},
PAGES = {269},
PUBLISHER = {Wissenschaftsverlag Mainz},
ADDRESS = {Lehrstuhl für Kommunikationsnetze},
SCHOOL = {Aachen University},
AFFILIATION = {Chair of Communication Networks (ComNets), Faculty 6, RWTH Aachen University},
ISBN = {3-86130-936-X},
URL = {https://www.comnets.rwth-aachen.de}
}
Signature in CN-Library = {Qa 057}