Wang C.-W.,MStar Semiconductor Inc. |
Wang L.-C.,National Chiao Tung University
IEEE Journal on Selected Areas in Communications | Year: 2012
In this paper, we present an analytical framework to evaluate the effects of multiple spectrum handoffs on channel utilization and latency performances in cognitive radio (CR) networks. During the transmission period of a secondary connection, multiple interruptions from the primary users result in multiple spectrum handoffs. In order to decide the target channel for each spectrum handoff and resume the unfinished transmission, wideband sensing is performed in an on-demand reactive manner. Although spectrum handoff procedure can enhance channel utilization, transmission latency of the secondary users is prolonged due to multiple handoffs. Thus, two fundamental issues in CR networks with multiple spectrum handoffs arise: (1) to what extent the channel utilization can be improved; and (2) how long the transmission latency will be extended for the secondary users. To solve the first problem, we introduce the preemptive resume priority (PRP) M/G/1 queueing network to characterize the channel usage behaviors of CR networks. Based on this queueing network, channel utilization under various traffic arrival rates and service time distributions can be evaluated. Furthermore, on top of the proposed queueing network, a state diagram is developed to characterize the effects of multiple handoff delay on the transmission latency of the secondary users. The analytical results can provide a helpful insight to study the effects of traffic arrival rates and service time on channel utilization and transmission latency and then facilitate the designs of admission control rules for the secondary users subject to their performance requirements. © 2012 IEEE. Source
MStar Semiconductor Inc. | Date: 2015-04-08
A correcting method for a display apparatus is provided. For N original grayscale combinations, color performances of the display apparatus are respectively measured to generate N measurement results. A set of color blending equations are utilized for M original grayscale combinations according to the N measurement results to generate M blended results. From the N measurement results and the M blended results, P color performances respectively most approximate to P target performances are identified. The P target color performances correspond to P target grayscale combinations. The P color performances correspond to P original grayscale combinations in the (N+M) original grayscale combinations. A look-up table for correcting the display apparatus is established according to the P target grayscale combinations and the P corresponding original grayscale combinations.
MStar Semiconductor Inc. | Date: 2015-12-18
A mobile electronic device is provided by the present invention. The mobile electronic device is configured to display a frame, which includes an image region and an icon. The icon is associated with a status of an application program of the electronic device, and the image region includes the icon. The mobile electronic device includes a memory and a processing unit. The processing unit stores an image of the icon into the memory, updates the image of the icon according to the status of the application program, and stores the updated image of the icon into the memory. When displaying the image region, the icon is drawn by using the updated image of the icon in the memory.
MStar Semiconductor Inc. | Date: 2015-05-22
A scheduling method includes: determining whether a valid time interval is shorter than a first time interval; and when the valid time interval is smaller than the first time interval, performing a search for a time length of N predetermined search cycles. In each of the predetermined search cycles, N consecutive TD-SCDMA sub-frames are regarded as a group, and one fixed sub-frame in the group is selected for the search. In the N predetermined search cycles, the fixed sub-frames selected from the group in respective predetermined search cycles are different. N is a natural number greater than or equal to 2.
MStar Semiconductor Inc. | Date: 2015-02-13
An electrode of a self-capacitive touch panel is provided. The electrode, coupled to a control circuit of the self-capacitive touch panel via a conducting wire, includes: a serpentine portion, having a first side; a main portion, having a second side; and a connecting portion, connected to the first side and the second side to connect the serpentine portion and the main portion. A length of the connecting portion is smaller than a length of the first side and a length of the second side.