Browsing by Author "Lin, Chen-Yang"

Now showing 1 - 9 of 9

A 40 nm 535 Mbps Multiple Code-Rate Turbo Decoder Chip Using Reciprocal Dual Trellis
(2013-11-01)
Lin, Chen-Yang
;
Wong, Cheng-Chi
;
Chang, Hsie-Chia
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper presents a multiple code-rate turbo decoder using the reciprocal dual trellis to improve the hardware efficiency. For a convolutional code with code rate k/(k + 1), its corresponding reciprocal dual code with rate 1/(k + 1) has smaller codeword space than the original code while k > 1, leading to a simplified trellis of the high code-rate code. The proposed decoder architecture can decode code rate k/(k + 1) constituent convolutional codes for k = 1, 2, 4, 8, and 16. Moreover, two parallel soft-in/soft-out (SISO) decoders are exploited in our turbo decoder by using the quadratic permutation polynomial (QPP) interleaver to improve the decoding speed. After fabricated in 1P9M CMOS 40 nm process, the proposed decoder with 1.27 mm(2) core area can achieve 535 Mbps throughput at 8/9 code rate, and the energy efficiency is 0.068 nJ/bit/iteration at 0.9 V.
A 40 nm 535 Mbps Multiple Code-Rate Turbo Decoder Chip Using Reciprocal Dual Trellis
(2012)
Lin, Chen-Yang
;
Wong, Cheng-Chi
;
Chang, Hsie-Chia
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper presents a turbo decoder chip which can decode code rate k/(k + 1) constituent convolutional codes for k = 1, 2, 4, 8, and 16. After replacing the constituent code by its code rate 1/(k + 1) reciprocal dual code, we can derive a smaller codeword space and design a simpler decoding trellis structure for high code-rate SISO decoder. In addition, two parallel SISO decoders are exploited in our turbo decoder by using the quadratic permutation polynomial (QPP) interleaver to improve the decoding speed. After fabricated in 1P9M CMOS 40 nm process, the proposed decoder with 1.27 mm(2) core area can achieve 535 Mbps throughput at 8/9 code rate, and the energy efficiency is 0.068 nJ/bit/iteration at 0.9 V.
A ISS-Length Full Code Rate 333Mbps 1.08mm(2) Radix-4 Hybrid-Trellis Thrbo Decoder with Zero Patching for 3GPP LTE-A
(2018-01-01)
Chang, Po-Hsun
;
Lin, Chen-Yang
;
Sun, Chia-Hsiang
;
Liao, Yen-Chin
;
Chang, Hsie-Chia
Decoding high code rate Thrbo codes by their reciprocal dual trellis has been shown to be potentially beneficial in implementation due to the simpler trellis structures. However, reciprocal dual trellis decoders' complexity grows significantly when the code rate is less than 1/2. Further, designing a multi-code rate reciprocal dual trellis decoder is even more challenging if periodical puncturing patterns is not always available. In this paper, a radix-4 hybrid-trellis LTE-A turbo decoder with a controller switching between the conventional trellis and the reciprocal dual trellis is presented. To accommodate all the rates defined in LTE-A, a zero patching scheme is proposed to create the periodical puncturing patterns required by the reciprocal dual trellis decoding. The implementation of the proposed decoder supports all the code rates, from 1/3 to 0.95, and all the 188 block lengths. Fabricated in TSMC TN28HPM process, the post-layout simulations show the proposed decoder could achieve 333Mbps at 6 iterations under 263MHz operating frequency. The core area is 1.08 mm(2), and the decoder draws 295.57 mW of power with energy efficiency of 0.148(nJ/bitJiter).
A Multiple Code-Rate Turbo Decoder Based on Reciprocal Dual Trellis Architecture
(2010)
Lin, Chen-Yang
;
Wong, Cheng-Chi
;
Chang, Hsie-Chia
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
To increase channel efficiency for high throughput systems, the high code-rate schemes are usually required. However, conventional turbo decoders in high code-rate usually apply high radix trellis structure, and the complexity of the trellis increases exponentially according to the code-rate. In this paper, the reciprocal dual trellis is applied to reduce the trellis complexity and a multiple code-rate turbo decoder is proposed. A sign magnitude representation is also introduced to lower the hardware complexity. The puncturing methodology is applied to WCDMA system as a case study of high code-rate turbo codes, and the investigated code-rates are 1/3, 1/2, 2/3, and 4/5. The simulation results are also shown in this paper. Fabricated with CMOS 90nm process, the proposed decoder containing 370K logic gates and 58kb storage units can achieve 101Mb/s with 80mW at code-rate 4/5.
A New Compliant Motion Control Design of a Walking-Help Robot Based on Motor Current and Speed Measurement
(2009)
Song, Kai-Tai
;
Lin, Chen-Yang
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper presents a novel compliant motion controller design for an omni-directional mobile robot. In this design, an external force observer is developed based on measuring motor current and speed without using an expensive force/torque sensor. The mobile robot has a handrail to assist the elderly to walk safely and stably. In this application, adaptive motion compliance is required in accordance with the applied force of the user. Practical experimental results show that the compliance of the walking helper can be adjusted by setting dynamic coefficients of the overall dynamical system. It was demonstrated that the external force observer successfully detected the pushing as well as pulling force of a user on the handrail. The velocity of the omni-directional walking helper is adjusted according to the inferred motion intent.
An Area Efficient Radix-4 Reciprocal Dual Trellis Architecture for a High-Code-Rate Turbo Decoder
(2015-01-01)
Lin, Chen-Yang
;
Wong, Cheng-Chi
;
Chang, Hsie-Chia
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This brief presents an area-efficient turbo decoder based on the reciprocal dual trellis. In this brief, the radix-4 structure is introduced into the reciprocal dual trellis for throughput enhancement, and a sign-arrangement technique is developed to simplify the hardware and reduce the critical path of the recursion metric unit. To further reduce the hardware complexity, a time-multiplexing method with no degradation of throughput is also presented to save half of the extrinsic units, leading to a 15% hardware reduction of the soft-in/soft-out decoder. After implementation by CMOS 90-nm process, the proposed turbo decoder containing 600 k-gates and 152-kb SRAM can achieve 425 Mb/s with 310-mW power consumption at 8/9 code rate. The post-simulation results show that the proposed methods provide a hardware-efficient solution for turbo decoders exploiting high-code-rate operations.
Development of the Robot of Living Aid: RoLA
(2008)
Song, Kai-Tai
;
Tsai, Chi-Yi
;
Huang, Fu-Sheng
;
Hong, Jung-Wei
;
Lin, Chen-Yang
With increasing number of aging people, taking care of the elderly will become more and more important for future society, especially for those elderly living alone. This paper presents an autonomous mobile robot Rola (Robot of LivingAid), which can handle certain emergency conditions in a home setting to help the elderly through multi-modal sensing and control functions. The implemented functions include visual tracking, video transmission, location aware, navigation, body pose recognition and emergency call out. Rola can accommodate smoothly to the movement of a user through face tracking and performs robot-assisted video conferencing. Rola follows the elderly in the living room using the developed RF-based location aware system. It avoids obstacles in a narrow space employing a laser scanner. Further, Rola can help the elderly as he/she falls down at home. This accidental situation can be detected with a tri-axial accelerometer mounted on the waist of the elderly. It approaches to the elderly by the help of location-aware system and provides timely help through automatic call out and wireless video transmission.
NURSING SYSTEM
(2009-08-06)
Tsai, Chi-Yi
;
Huang, Fu-Sheng
;
Lin, Chen-Yang
;
Lin, Zhi-Sheng
;
Chen, Chun-Wei
A nursing system of the present invention can position where a person to be nursed through a sensor network widely deployed in an environment, instantaneously detect if the person to be nursed has an accident, and forward a message to inform a relative or medical staff. An autonomous robot will actively move beside the person to be nursed and transmit real-time images to a remote computer or PDA so that the relative or medical staff can swiftly ascertain the situation of the person to be nursed and the person to be nursed in case of emergency can be rescued as soon as possible.
Shared Control Design of a Walking-Assistant Robot
(2017-11-01)
Jiang, Sin-Yi
;
Lin, Chen-Yang
;
Huang, Ko-Tung
;
Song, Kai-Tai
;
電控工程研究所
This brief presents a control design for a walking-assistant robot in a complex indoor environment, such that it can assist a walking-impaired person to walk and avoid unexpected obstacles. In this design, the robot motion is a resultant of autonomous navigation and compliant motion control. The compliance motion controller allows the robot to possess passive behavior following the motion intent of the user, while the autonomous guidance gives safe navigation of the robot without colliding with any obstacles. A shared-control approach is suggested to combine the passive compliant behavior and safe guidance of the robot. When a user exerts force to the robot, the mobile platform responds to adjust the speed in compliance with the user movement. On the other hand, the autonomous navigation controller is designed to provide collision free guidance. Using the developed shared controller, outputs of the compliance motion controller and autonomous navigation controller are fused to generate appropriate motion for the robot. In this manner, passive behavior allows the walking-assistant robot to adapt to a user's motion intent and move in compliance with user. Meanwhile, the active guidance adjusts the linear velocity and the direction of the robot in real time in response to the environmental data received from the on-board laser scanner. The developed algorithms have been implemented on a self-constructed walking-assistant robot. Experimental results validate the proposed design and demonstrate that the robot can actively avoid unexpected obstacles while move passively following the user to the destination.