Time-based power control architecture for application processors in smartphones

Proposed is an architecture for reducing the power consumption of an application processor (AP) in a smartphone. The proposed architecture is designed for sharing the main memory between the AP and modem blocks. A power-saving algorithm is proposed that focuses on random and sparse data patterns in connected and idle modes. The algorithm automatically performs power/clock gating without the intervention of the CPU, unlike dynamic voltage and frequency scaling. To control power gating, a power consumption model is formulated to solve an optimisation problem. The proposed algorithm is verified with electronic system level simulation based on actual scenarios of a mobile terminal. The results show an improvement in power consumption.X1144sciescopu

Data Page Reconstruction based on Two-Dimensional Soft Output Viterbi Algorithm with Self-Reference for Holographic Data Storage

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Second-Order Discrete-Time Sliding Mode Observer for State of Charge Determination Based on a Dynamic Resistance Li-Ion Battery Model

A second-order discrete-time sliding mode observer (DSMO)-based method is proposed to estimate the state of charge (SOC) of a Li-ion battery. Unlike the first-order sliding mode approach, the proposed method eliminates the chattering phenomenon in SOC estimation. Further, a battery model with a dynamic resistance is also proposed to improve the accuracy of the battery model. Similar to actual battery behavior, the resistance parameters in this model are changed by both the magnitude of the discharge current and the SOC level. Validation of the dynamic resistance model is performed through pulse current discharge tests at two different SOC levels. Our experimental results show that the proposed estimation method not only enhances the estimation accuracy but also eliminates the chattering phenomenon. The SOC estimation performance of the second-order DSMO is compared with that of the first-order DSMO

Design for Layer Jump in Optical Disc Drives Using Internal State Manipulation

Layer jump operation is a vertical seek operation of an actuator between adjacent data layers in an optical disc. As a number of the data layers are raised for high capacity data, the layer jump gradually gains importance for fast playing and recording. Therefore, a systematic design methodology for the layer jump is required to guarantee layer pull-in stability and robustness of model uncertainty. In this paper, a layer jump strategy is proposed for minimizing transient motion and overcoming the effect of model uncertainty by estimating the current velocity of the actuator. The proposed algorithm has been implemented in a system-on-chip for a multi-layered Blu-ray disc drive. The experimental results show the notable performance of the proposed algorithm(1).X11sciescopu

Second-Order Discrete-Time Sliding Mode Observer for State of Charge Determination Based on a Dynamic Resistance Li-Ion Battery Model

A second-order discrete-time sliding mode observer (DSMO)-based method is proposed to estimate the state of charge (SOC) of a Li-ion battery. Unlike the first-order sliding mode approach, the proposed method eliminates the chattering phenomenon in SOC estimation. Further, a battery model with a dynamic resistance is also proposed to improve the accuracy of the battery model. Similar to actual battery behavior, the resistance parameters in this model are changed by both the magnitude of the discharge current and the SOC level. Validation of the dynamic resistance model is performed through pulse current discharge tests at two different SOC levels. Our experimental results show that the proposed estimation method not only enhances the estimation accuracy but also eliminates the chattering phenomenon. The SOC estimation performance of the second-order DSMO is compared with that of the first-order DSMO.open112018sciescopu