Browsing by Author "Yen, Shao-Wei"

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A 0.92mm(2) 23.4mW Fully-Compliant CTC Decoder for WiMAX 802.16e Application
(2009)
Yen, Shao-Wei
;
Hu, Ming-Chih
;
Chen, Chih-Lung
;
Chang, Hsie-Chia
;
Jou, Shyh-Jye
An area-efficient and fully-compliant decoder for convolutional turbo code (CTC) of WiMAX 802.16e is presented. The proposed decoder can support all 17 modes specified in IEEE 802.16e system. By scaling the extrinsic information, the Max-Log MAP algorithm is used to reduce the hardware complexity with the minimized performance loss. A two-phase extrinsic memory and reversed sliding window technique are demonstrated for less memory requirement and decoding latency. Moreover, a division-free reconfigurable interleaver architecture is implemented by simple addition and subtraction instead of division. Fabricated with the 90nm CMOS process, the proposed CTC decoder chip which occupies core area of 0.92mm(2) can achieve 30Mb/s with 23.4mW power consumption.
A 5.79-Gb/s Energy-Efficient Multirate LDPC Codec Chip for IEEE 802.15.3c Applications
(2012-09-01)
Yen, Shao-Wei
;
Hung, Shiang-Yu
;
Chen, Chih-Lung
;
Chang, Hsie-Chia
;
Jou, Shyh-Jye
"An LDPC codec chip supporting four code rates of IEEE 802.15.3c applications is presented. After utilizing row-based layered scheduling, the normalized min-sum (NMS) algorithm can reduce half of the iteration number while maintaining similar performance. According to the unique code structure of the parity-check matrix, a reconfigurable 8/16/32-input sorter is designed to deal with LDPC codes in four different code rates. Both sorter input reallocation and pre-coded routing switch are proposed to alleviate routing complexity, leading to 64% input reduction of multiplexers. In addition, an adder-accumulator-shift register (AASR) circuit is proposed for the LDPC encoder to reduce hardware complexity. After implemented in 65-nm 1P10M CMOS process, the proposed LDPC decoder chip can achieve maximum 5.79-Gb/s throughput with the hardware efficiency of 3.7 Gb/s mm(2) and energy efficiency of 62.4 pJ/b, respectively."