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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. |
