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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design and Implementation of a Low-cost DVB Channel Decoder

Wang, Jhih-Jian 06 September 2005 (has links)
In this thesis, a highly efficient implementation of the channel decoder for terrestrial digital video broadcast (DVBT) standard is proposed. DVB-T channel decoder is mainly composed of four major modules including the inner Viterbi decoder, outer Reed-Solomon decoder and inner and outer de-interleaver modules which all require significant amount of intermediate data storage. The main contribution of this thesis is to propose suitable architectural solution for each individual module to achieve efficient realization of the data storage mostly by single-port memory blocks which can lead to the reduction of silicon area and the dynamic power dissipation. For the outer convolutional deinterleaver module, a special address generator has been proposed such that the data deinterleaver path can be merged and implemented as three memory blocks. For the inner symbol deinterleaver module, a lookahead technique has been applied to the design of address generator that can generate valid deinterleaving address each cycle to avoid the buffering problem. In addition, a novel deinterleaver memory partitioning architecture is proposed such that the entire deinterleaver can be built on four single-port memory banks. These four modules have been verified and integrated as a robust channel decoder silicon intellectual property (IP). Our implementation result shows that the core area of entire DVB-T channel decoder IP (Intellectual Property) can be realized in less than 6.8 mm2 in 0.18-µm TSMC technology.
2

Design and Implementation of Low-Cost Dual Mode Channel Decoder

Ding, Yu-Chung 14 September 2006 (has links)
This thesis addresses the design and implementation of a dual-mode channel decoder for two advanced wireless communication systems. One of the targetsystems is the digital video broadcasting for hand-held terminals (DVB-H) , and the other one is Worldwide Interoperability for Microwave Access (WiMAX) system based on the recently approved IEEE 802.16e. Both standards promise to deliver high data bandwidth within very broad regions. The error control coding schemes of both standards are all built on the similar concatenated code, with the exception of the way of data interleaving. Therefore, the decoders for both standards can be highly integrated. To achieve the low-cost and low-power decoder, this thesis proposes several novel design ideas. First, a fast dynamic multiple path convergence mechanism is proposed for the design of Viterbi decoder module, which can determine the survivor path at earlier stage. Furthermore, a new modified forward path prediction method is also presented which can efficiently predict the possiblesurvivor path such that the number of memory operations during the trace-back canbe significantly reduced. The proposed methodology can reduce up to 50% to 80%of memory operations compared with the best prediction scheme in the literature at high signal-to-noise ration. Secondly, for the block deinterleaver adopted by IEEE 802.16. a new multi-bank architecture is proposed by properly splitting and allocating the input data to suitable bank. The proposed block deinterleaver can be highly integrated with the byte-level convolutional deinterleaver adopted by the DVB-H standard by realizing the multiply First-In-First-Out (FIFO) data branches as the circular buffer. The other salient feature of the proposed dual-mode decoder is that all the major data storage units can all be realized by single-port memory such that the overall cost can be highly reduced.
3

Analysis of the effects of phase noise and frequency offset in orthogonal frequency division multiplexing (OFDM) systems

Erdogan, Ahmet Yasin 03 1900 (has links)
Approved for public release, distribution is unlimited / Orthogonal frequency division multiplexing (OFDM) is being successfully used in numerous applications. It was chosen for IEEE 802.11a wireless local area network (WLAN) standard, and it is being considered for the fourthgeneration mobile communication systems. Along with its many attractive features, OFDM has some principal drawbacks. Sensitivity to frequency errors is the most dominant of these drawbacks. In this thesis, the frequency offset and phase noise effects on OFDM based communication systems are investigated under a variety of channel conditions covering both indoor and outdoor environments. The simulation performance results of the OFDM system for these channels are presented. / Lieutenant Junior Grade, Turkish Navy

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