Patents by Inventor Yu Hao Chang
Yu Hao Chang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20140362811Abstract: Sounding mechanism for LTE-A systems under carrier aggregation is provided. A UE receives an uplink or downlink grant transmitted from an eNB over a primary carrier in a multi-carrier LTE-A system. The UE determines indicated carrier(s) and detects a triggering condition for aperiodic sounding transmission in the grant. The UE then selects UE-specific sounding reference signal (SRS) parameters. Finally, the UE transmits an aperiodic SRS (ap-SRS) over the indicated carrier(s) using the selected UE-specific SRS parameters. In one embodiment, the uplink or downlink grant is transmitted via a PDCCH carrying various DCI formats. Each DCI format contains a carrier indicator field (CIF) that indicates which carrier is used for ap-SRS transmission if cross-carrier scheduling is enabled. In another embodiment, DCI format 3/3A is transmitted via a PDCCH carrying a plurality of information fields, each field indicates if the UE should enable ap-SRS in a particular carrier.Type: ApplicationFiled: August 25, 2014Publication date: December 11, 2014Inventors: Chih-Yuan Lin, Yu-Hao Chang
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Patent number: 8837394Abstract: Sounding mechanism for LTE-A systems under carrier aggregation is provided. A UE receives an uplink or downlink grant transmitted from an eNB over a primary carrier in a multi-carrier LTE-A system. The UE determines indicated carrier(s) and detects a triggering condition for aperiodic sounding transmission in the grant. The UE then selects UE-specific sounding reference signal (SRS) parameters. Finally, the UE transmits an aperiodic SRS (ap-SRS) over the indicated carrier(s) using the selected UE-specific SRS parameters. In one embodiment, the uplink or downlink grant is transmitted via a PDCCH carrying various DCI formats. Each DCI format contains a carrier indicator field (CIF) that indicates which carrier is used for ap-SRS transmission if cross-carrier scheduling is enabled. In another embodiment, DCI format 3/3A is transmitted via a PDCCH carrying a plurality of information fields, each field indicates if the UE should enable ap-SRS in a particular carrier.Type: GrantFiled: June 17, 2011Date of Patent: September 16, 2014Assignee: Mediatek Inc.Inventors: Chih-Yuan Lin, Yu-Hao Chang
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Patent number: 8799735Abstract: A channel interleaver comprises a novel constellation-based permutation module. The channel interleaver first receives a plurality of sets of encoded bits generated from an FEC encoder. The encoded bits are distributed into multiple subblocks and each subblock comprises a plurality of adjacent bits. A subblock interleaver interleaves each subblock and outputs a plurality of interleaved bits. The constellation-based permutation module rearranges the interleaved bits and outputs a plurality of rearranged bits. The rearranged bits are supplied to a symbol mapper such that a plurality of consecutively encoded bits in the same set of the encoded bits generated from the FEC encoder is prevented to be mapped onto the same level of bit reliability of a modulation symbol. In addition, the plurality of adjacent bits of each subblock is also prevented to be mapped onto the same level of bit reliability to achieve constellation diversity and to improve decoding performance.Type: GrantFiled: December 30, 2009Date of Patent: August 5, 2014Assignee: Mediatek Inc.Inventors: Ciou-Ping Wu, Pei-Kai Liao, Yu-Hao Chang, Yih-Shen Chen
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Publication number: 20140146779Abstract: Methods to manage multiple component carriers (CCs) efficiently in a mobile network with carrier aggregation (CA) enabled are proposed. For CC activation/deactivation, a single LCID value is used to represent both activation and deactivation command. A single command with multiple instructions is provided to activate and/or deactivate multiple CCs. In addition, unnecessary re-activation or re-inactivation of a CC is prevented, and explicit feedback for activation/deactivation is considered. For scheduling mechanism, a novel buffer status reporting (BSR) procedure is provided, where only one BSR is calculated after preparing all the transport blocks (TB) within one transmission time interval (TTI). Novel power headroom reporting (PHR) format and trigger are also provided. For DL-UL linking, various linking types are created based on whether there is carrier indicator field (CIF) in DL grant or UL grant.Type: ApplicationFiled: January 30, 2014Publication date: May 29, 2014Applicant: MEDIATEK, INC.Inventors: Chia-Chun Hsu, Yih-Shen Chen, Yu-Hao Chang, I-Kang Fu
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Patent number: 8619673Abstract: Two preamble partition schemes are provided for flexible network deployment and efficient utilization of limited cell identification resources in a wireless network. In a soft partition scheme, the entire preamble sequences are partitioned into several configurable non-overlapping subsets, and each subset is associated with a corresponding cell type. In a hybrid partition scheme, a combination of fixed and configurable subsets is used for preamble partition. The partitioning information is carried in a broadcasting channel broadcasted from base stations to mobile stations. In one embodiment, after a mobile station performs scanning and synchronization with a first base station, it derives the cell type of the first base station from cell identification and partitioning information. The mobile station completes ranging and network entry with the first base station if the cell type is preferred, and starts to perform scanning and synchronization with a second base station if the cell type is non-preferred.Type: GrantFiled: July 6, 2010Date of Patent: December 31, 2013Assignee: Mediatek Inc.Inventors: Yu-Hao Chang, Yih-Shen Chen, Pei-Kai Liao
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Patent number: 8588205Abstract: A method of power control message indexing is provided in a wireless Orthogonal Frequency Division Multiple Access (OFDMA) network. A base station configures fast feedback channels (FFBCHs) and mobile stations report downlink channel information via the configured FFBCHs. Based on the received channel information, the base station estimates uplink channel quality and detects any channel variation. In response to uplink channel variation, the base station delivers power offsets to adjust the transmit power levels of the mobile stations. In one advantageous aspect, the power control commands for mobile stations are aggregated and the indexing scheme of the power control commands is implicitly based on the configured FFBCHs. For example, if a FFBCH is located at a first location in an uplink frame, then a following power control command in response to the FFBCH is located at a second location in a downlink frame, the second location is located after the first location with a predefined fixed delay time.Type: GrantFiled: September 30, 2010Date of Patent: November 19, 2013Assignee: Mediatek Inc.Inventors: Yu-Hao Chang, Yih-Shen Chen
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Patent number: 8576786Abstract: A hierarchical downlink (DL) synchronization channel (SCH) is provided for wireless OFDM/OFDMA systems. The SCH includes a Primary SCH (P-SCH) for carrying PA-Preambles used for coarse timing and frequency synchronization, and a Secondary SCH (S-SCH) for carrying SA-Preambles used for cell ID detection. The total time length occupied by P-SCH and S-SCH is equal to one OFDM symbol time length of a data channel, and S-SCH is located in front of P-SCH in each DL frame. A perfect multi-period time-domain structure is created and maintained in P-SCH to increase preciseness of frame boundary estimation. With overlapping deployment of macrocells and femtocells, a predefined SCH configuration scheme is provided to separate frequency subbands used for macrocells and femtocells such that interferences in S-SCH can be mitigated. In addition, a self-organized SCH configuration scheme is provided to allow more flexibility for femtocells to avoid or introduce interference in S-SCH.Type: GrantFiled: December 30, 2009Date of Patent: November 5, 2013Assignee: MediatekInventors: Pei-Kai Liao, Yu-Hao Chang, Kuo-Ming Wu
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Patent number: 8520542Abstract: A method of uplink power control in a wireless OFDMA system is provided. A serving base station first configures a fast feedback channel by transmitting a feedback allocation message to a mobile station. The mobile station then reports downlink channel information via the allocated fast feedback channel. Based on the reported downlink channel information, the serving base station estimates uplink channel quality and thereby detects a channel variation and generates an uplink power adjustment message that delivers a power offset to adjust the transmitting power level of the mobile station. In one novel aspect, the uplink power adjustment message also comprises feedback allocation information that re-configures the fast feedback channel without extra signaling overhead. In addition, the novel power adjustment message eliminates redundant information such that it is transmitted via a minimum resource unit without requiring extra resource.Type: GrantFiled: September 30, 2010Date of Patent: August 27, 2013Assignee: MediaTek Inc.Inventors: Yu-Hao Chang, Yih-Shen Chen
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Patent number: 8468396Abstract: A channel interleaver comprises a novel constellation-based permutation module. The channel interleaver first receives a plurality of sets of encoded bits generated from an FEC encoder. The encoded bits are distributed into multiple subblocks and each subblock comprises a plurality of adjacent bits. A subblock interleaver interleaves each subblock and outputs a plurality of interleaved bits. The constellation-based permutation module rearranges the interleaved bits and outputs a plurality of rearranged bits. The rearranged bits are supplied to a symbol mapper such that a plurality of consecutively encoded bits in the same set of the encoded bits generated from the FEC encoder is prevented to be mapped onto the same level of bit reliability of a modulation symbol. In addition, the plurality of adjacent bits of each subblock is also prevented to be mapped onto the same level of bit reliability to achieve constellation diversity and to improve decoding performance.Type: GrantFiled: December 30, 2009Date of Patent: June 18, 2013Assignee: Mediatek, Inc.Inventors: Ciou-Ping Wu, Pei-Kai Liao, Yu-Hao Chang, Yih-Shen Chen
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Publication number: 20130139123Abstract: A method to check circuit diagram data using a computing device. The computing device inserts the circuit diagram data into an application having an ordering function. The computing device sets a condition to screen out the circuit diagram data in the application having the ordering function, and reads an item of the circuit diagram data. The computing device marks the item of the circuit diagram data if the item of the circuit diagram data does not satisfy the condition.Type: ApplicationFiled: October 22, 2012Publication date: May 30, 2013Inventors: CONG-FENG WEI, YU-HAO CHANG
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Patent number: 8374139Abstract: In advanced wireless OFDMA communication systems, hierarchical synchronization is adopted to synchronize between a base station (BS) and a mobile station (MS). In a hierarchical synchronization architecture, primary advanced preamble (PA-Preamble) is used for coarse time domain synchronization while cell ID is detected using several accumulated secondary advanced preambles (SA-Preambles). Network entry latency can be reduced by adjusting the relative location of superframe header (SFH), PA-Preamble and SA-Preambles within a superframe. Three different synchronization channel (SCH) architectures are proposed to provide different tradeoffs between network entry latency and the robustness of SA-Preamble design and cell ID detection.Type: GrantFiled: December 30, 2009Date of Patent: February 12, 2013Assignee: Mediatek Inc.Inventors: Yu-Hao Chang, Pei-Kai Liao
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Patent number: 8239560Abstract: A system of remote objects with network streaming ability includes a streaming client, a plurality of streaming servers, a streaming buffer area, a plurality of first continuous buffer areas, a streaming controller, a plurality of first network connections, and a plurality of second network connections. The plurality of streaming servers is used to respond a remote procedure call from the streaming client. The streaming buffer area stores a complete data unit for the streaming client to access. A generation method of remote objects with network streaming ability is further provided. The method includes executing a link procedure, executing a streaming preparation, executing a streaming transfer procedure, and closing the link procedure.Type: GrantFiled: September 28, 2007Date of Patent: August 7, 2012Assignee: National Tsing Hua UniversityInventors: Jenq Kuen Lee, Chung Kai Chen, Yu Hao Chang, Chih Chieh Yang, Kai Hsin Chung
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Publication number: 20110310818Abstract: Sounding mechanism for LTE-A systems under carrier aggregation is provided. A UE receives an uplink or downlink grant transmitted from an eNB over a primary carrier in a multi-carrier LTE-A system. The UE determines indicated carrier(s) and detects a triggering condition for aperiodic sounding transmission in the grant. The UE then selects UE-specific sounding reference signal (SRS) parameters. Finally, the UE transmits an aperiodic SRS (ap-SRS) over the indicated carrier(s) using the selected UE-specific SRS parameters. In one embodiment, the uplink or downlink grant is transmitted via a PDCCH carrying various DCI formats. Each DCI format contains a carrier indicator field (CIF) that indicates which carrier is used for ap-SRS transmission if cross-carrier scheduling is enabled. In another embodiment, DCI format 3/3A is transmitted via a PDCCH carrying a plurality of information fields, each field indicates if the UE should enable ap-SRS in a particular carrier.Type: ApplicationFiled: June 17, 2011Publication date: December 22, 2011Inventors: Chih-Yuan Lin, Yu-Hao Chang
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Publication number: 20110310830Abstract: A communication apparatus is provided. A controller module generates a suggested sub-frame pattern describing suggested arrangement of one or more almost blank sub-frame(s) in one or more frame(s) and schedules control signal and/or data transmissions according to the suggested sub-frame pattern. A radio frequency module transmits at least a first signal carrying information regarding the suggested sub-frame pattern to a peer communications apparatus. The peer communications apparatus does not schedule data transmissions in the almost blank sub-frame(s).Type: ApplicationFiled: June 20, 2011Publication date: December 22, 2011Applicant: MEDIATEK INC.Inventors: Ciou-Ping Wu, Chien-Hwa Hwang, Yu-Hao Chang
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Publication number: 20110243106Abstract: Methods to manage multiple component carriers (CCs) efficiently in a mobile network with carrier aggregation (CA) enabled are proposed. For CC activation/deactivation, a single LCID value is used to represent both activation and deactivation command. A single command with multiple instructions is provided to activate and/or deactivate multiple CCs. In addition, unnecessary re-activation or re-inactivation of a CC is prevented, and explicit feedback for activation/deactivation is considered. For scheduling mechanism, a novel buffer status reporting (BSR) procedure is provided, where only one BSR is calculated after preparing all the transport blocks (TB) within one transmission time interval (TTI). Novel power headroom reporting (PHR) format and trigger are also provided. For DL-UL linking, various linking types are created based on whether there is carrier indicator field (CIF) in DL grant or UL grant.Type: ApplicationFiled: April 1, 2011Publication date: October 6, 2011Inventors: Chia-Chun Hsu, Yih-Shen Chen, Yu-Hao Chang, I-Kang Fu
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Publication number: 20110199990Abstract: A method of uplink power control in a wireless OFDMA system is provided. A serving base station first configures a fast feedback channel by transmitting a feedback allocation message to a mobile station. The mobile station then reports downlink channel information via the allocated fast feedback channel. Based on the reported downlink channel information, the serving base station estimates uplink channel quality and thereby detects a channel variation and generates an uplink power adjustment message that delivers a power offset to adjust the transmitting power level of the mobile station. In one novel aspect, the uplink power adjustment message also comprises feedback allocation information that re-configures the fast feedback channel without extra signaling overhead. In addition, the novel power adjustment message eliminates redundant information such that it is transmitted via a minimum resource unit without requiring extra resource.Type: ApplicationFiled: September 30, 2010Publication date: August 18, 2011Inventors: Yu-Hao Chang, Yib-Shen Chen
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Publication number: 20110199945Abstract: A method of power control message indexing is provided in a wireless Orthogonal Frequency Division Multiple Access (OFDMA) network. A base station configures fast feedback channels (FFBCHs) and mobile stations report downlink channel information via the configured FFBCHs. Based on the received channel information, the base station estimates uplink channel quality and detects any channel variation. In response to uplink channel variation, the base station delivers power offsets to adjust the transmit power levels of the mobile stations. In one advantageous aspect, the power control commands for mobile stations are aggregated and the indexing scheme of the power control commands is implicitly based on the configured FFBCHs. For example, if a FFBCH is located at a first location in an uplink frame, then a following power control command in response to the FFBCH is located at a second location in a downlink frame, the second location is located after the first location with a predefined fixed delay time.Type: ApplicationFiled: September 30, 2010Publication date: August 18, 2011Inventors: Yu-Hao Chang, Yih-Shen Chen
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Publication number: 20110007690Abstract: Two preamble partition schemes are provided for flexible network deployment and efficient utilization of limited cell identification resources in a wireless network. In a soft partition scheme, the entire preamble sequences are partitioned into several configurable non-overlapping subsets, and each subset is associated with a corresponding cell type. In a hybrid partition scheme, a combination of fixed and configurable subsets is used for preamble partition. The partitioning information is carried in a broadcasting channel broadcasted from base stations to mobile stations. In one embodiment, after a mobile station performs scanning and synchronization with a first base station, it derives the cell type of the first base station from cell identification and partitioning information. The mobile station completes ranging and network entry with the first base station if the cell type is preferred, and starts to perform scanning and synchronization with a second base station if the cell type is non-preferred.Type: ApplicationFiled: July 6, 2010Publication date: January 13, 2011Inventors: Yu-Hao Chang, Yih-Shen Chen, Pei-Kai Liao
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Publication number: 20100246508Abstract: In advanced wireless OFDMA communication systems, hierarchical synchronization is adopted to synchronize between a base station (BS) and a mobile station (MS). In a hierarchical synchronization architecture, primary advanced preamble (PA-Preamble) is used for coarse time domain synchronization while cell ID is detected using several accumulated secondary advanced preambles (SA-Preambles). Network entry latency can be reduced by adjusting the relative location of superframe header (SFH), PA-Preamble and SA-Preambles within a superframe. Three different synchronization channel (SCH) architectures are proposed to provide different tradeoffs between network entry latency and the robustness of SA-Preamble design and cell ID detection.Type: ApplicationFiled: December 30, 2009Publication date: September 30, 2010Inventors: Yu-Hao Chang, Pei-Kai Liao
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Publication number: 20100169738Abstract: A channel interleaver comprises a novel constellation-based permutation module. The channel interleaver first receives a plurality of sets of encoded bits generated from an FEC encoder. The encoded bits are distributed into multiple subblocks and each subblock comprises a plurality of adjacent bits. A subblock interleaver interleaves each subblock and outputs a plurality of interleaved bits. The constellation-based permutation module rearranges the interleaved bits and outputs a plurality of rearranged bits. The rearranged bits are supplied to a symbol mapper such that a plurality of consecutively encoded bits in the same set of the encoded bits generated from the FEC encoder is prevented to be mapped onto the same level of bit reliability of a modulation symbol. In addition, the plurality of adjacent bits of each subblock is also prevented to be mapped onto the same level of bit reliability to achieve constellation diversity and to improve decoding performance.Type: ApplicationFiled: December 30, 2009Publication date: July 1, 2010Inventors: Ciou-Ping Wu, Pei-Kai Liao, Yu-Hao Chang, Yih-Shen Chen