Patents by Inventor Der-Zheng Liu
Der-Zheng Liu 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).
-
Patent number: 8995248Abstract: A power adjusting apparatus communicating with a remote terminal is provided. The apparatus includes: a transceiving unit transmitting a plurality of test packets by a plurality of powers; a processing unit coupled to the transceiving unit, and deciding a transmission power for transmitting a subsequent packet according to at least one retransmission number of transmitting the test packets.Type: GrantFiled: February 14, 2012Date of Patent: March 31, 2015Assignee: Realtek Semiconductor Corp.Inventors: Wei-Hsuan Chang, Chung-Yao Chang, Der-Zheng Liu, Kuang-Yu Yen
-
Patent number: 8977218Abstract: A multi-mode wireless transceiver and a multi-mode switching method thereof are disclosed to provide at least one wireless transceiving interface capable of dynamically switching between multiple frequency bands. The wireless transceiver comprises: a first RF transceiving circuit for transceiving RF signals of a first frequency band; a second RF transceiving circuit for transceiving RF signals of a second frequency band; a first frequency synthesizer and a second frequency synthesizer for generating a first carrier of the first frequency band and a second carrier of the second frequency band respectively; and a switching circuit for outputting the first carrier to the first RF transceiving circuit, and for determining to output one of the first and second carriers to the second RF transceiving circuit according to a control signal.Type: GrantFiled: May 4, 2011Date of Patent: March 10, 2015Assignee: Realtek Semiconductor Corp.Inventors: Kuang Yu Yen, Der Zheng Liu
-
Patent number: 8964737Abstract: A wireless communication circuit for a wireless communication device having a plurality of antennas is disclosed. The wireless communication circuit includes: a transceiver for receiving and transmitting network packets; a control circuit for controlling the switching circuit to switch the transceiver among the antennas so that the transceiver receives the preamble of a first network packet; and a receiving signal strength detector for detecting the receiving signal strength value of respective antennas in respective receiving periods during the reception of the preamble conducted by the transceiver. If the receiving signal strength value of each antenna is less than a predetermined threshold, the control circuit selects an antenna with the maximum receiving strength value as a target antenna and controls the switching circuit to couple the transceiver to the selected target antenna so that the transceiver receives the rest of the first network packet through the target antenna.Type: GrantFiled: January 4, 2013Date of Patent: February 24, 2015Assignee: Realtek Semiconductor Corp.Inventors: Tsung-Hsuan Lee, Chung-Yao Chang, Der-Zheng Liu
-
Publication number: 20140307827Abstract: A communication device includes a plurality of host control interfaces, an interface detector, and a transmitter. The plurality of host control interfaces selectively connect to a connection interface of a host. The interface detector is coupled to the plurality of host control interfaces and utilized for determine an interface specification of the connection interface to generate a detection result. The transmitter is coupled to the interface detector and supports a plurality of transmission power levels. The transmitter is utilized for determining a plurality of transmission configurations, and selecting one of the transmission configurations to communicating with a receiver, wherein each of the transmission configurations determines a transmission power level configuration of the transmitter.Type: ApplicationFiled: April 9, 2014Publication date: October 16, 2014Applicant: Realtek Semiconductor Corp.Inventors: Der-Zheng Liu, Kuang-Yu Yen
-
Patent number: 8792575Abstract: A multiple-antenna receiver can enable and disable receive radio frequency front-end and analog front-end circuits of specific antenna receiving routes according to a predetermined scheme during the receive data phase. The predetermined scheme calculates signal quality indices of the receiving route antennas according to a preamble sequence, and derives the modulation and coding scheme and the number of spatial streams via the information provided by a header sequence. Indications of the signal quality indices are compared with threshold values to determine which receiving routes are to be turned on and which receiving routes are to be turned off.Type: GrantFiled: September 9, 2009Date of Patent: July 29, 2014Assignee: Realtek Semiconductor Corp.Inventors: Der-Zheng Liu, Jiun-Hung Yu, Kuang-Yu Yen
-
Patent number: 8767803Abstract: A wireless communication circuit is disclosed including: a transceiver for transmitting and receiving signals; and a control circuit coupled with the transceiver for controlling a switching circuit to switch the transceiver to a first antenna set for a first time period and then to switch the transceiver to a second antenna set for a second time period in a test period. If a throughput statistic of the first antenna set with respect to the test period is greater than that of the second antenna set, the control circuit configures the switching circuit to switch the transceiver to the first antenna set after the test period.Type: GrantFiled: August 16, 2012Date of Patent: July 1, 2014Assignee: Realtek Semiconductor Corp.Inventors: Tsung-Hsuan Lee, Chung-Yao Chang, Der-Zheng Liu
-
Patent number: 8665980Abstract: The present invention provides an antenna diversity apparatus and an antenna diversity method. The antenna diversity apparatus comprises: a plurality groups of antennas, a switching unit, a demodulating unit, an antenna switch selecting unit, and a control unit, wherein each group of the plurality groups of antennas comprises at least an antenna, and the control unit can comprises: a receiving signal quality detecting unit, a packet detecting unit, and an antenna decision unit. The antenna decision unit can be realized by hardware, firmware, or software, and the antenna switch selecting unit can be realized by hardware. The antenna diversity apparatus and the antenna diversity method provided by the present invention can switch antennas fast to avoid the defect of occurring burst error to reduce transmitting data rate, and switch to proper antennas fast when variation of the data transmission channels occurs.Type: GrantFiled: October 2, 2011Date of Patent: March 4, 2014Assignee: Realtek Semiconductor Corp.Inventors: Der-Zheng Liu, Yung-Ting Chen, Kuang-Yu Yen
-
Patent number: 8514781Abstract: The present invention provides a method for adjusting transmission power of a communication system having a first terminal and a second terminal. In accordance with a preferred embodiment, the method comprises steps of: (a) repeatedly transmitting a detecting packet from the first terminal to the second terminal by sequentially using one of a variety of transmission powers; (b) receiving a responding packet from the second terminal, wherein the responding packet corresponds to the one of the variety of transmission powers; and (c) choosing at least one from the variety of the transmission powers for transmitting at least a data packet to the second terminal therewith based on the responding packet from the second terminal.Type: GrantFiled: July 14, 2010Date of Patent: August 20, 2013Assignee: Realtek Semiconductor Corp.Inventors: Der-Zheng Liu, Kuang-Yu Yen, Jia-Ching Shen
-
Patent number: 8463214Abstract: An antenna diversity system having a non-interrupt function is provided. The antenna diversity system includes: a plurality of antennas, a plurality of radio frequency (RF) circuits, and a signal processing unit. The RF circuits are respectively coupled to the antennas, wherein each RF circuit is utilized for operating in one of a plurality of channels. The signal processing unit is coupled to the RF circuits, and utilized for determining whether a signal quality value of at least one of the antennas lower than a threshold to generate a determining result, and determining whether to change the channel of at least one of the RF circuits according to the determining result, so as to make at least two of the RF circuits operating in a same channel of the channels.Type: GrantFiled: October 18, 2011Date of Patent: June 11, 2013Assignee: Realtek Semiconductor Corp.Inventors: Kuang-Yu Yen, Der-Zheng Liu
-
Publication number: 20130051438Abstract: A wireless communication circuit is disclosed including: a transceiver for transmitting and receiving signals; and a control circuit coupled with the transceiver for controlling a switching circuit to switch the transceiver to a first antenna set for a first time period and then to switch the transceiver to a second antenna set for a second time period in a test period. If a throughput statistic of the first antenna set with respect to the test period is greater than that of the second antenna set, the control circuit configures the switching circuit to switch the transceiver to the first antenna set after the test period.Type: ApplicationFiled: August 16, 2012Publication date: February 28, 2013Inventors: Tsung-Hsuan LEE, Chung-Yao CHANG, Der-Zheng LIU
-
Patent number: 8284736Abstract: A multiple-antenna transceiver in the present invention includes a frame controller and circuitry for transmitting and receiving. The transmitting component includes a sequence selection circuit, a MIMO modulation and coding circuit, and numerous TX RFE and AFE circuits. The receiving component includes a MIMO demodulation and decoding circuit, a sequence separation circuit, and numerous RX RFE and AFE circuits. The frame controller can enable and disable the TX and RX RFE and AFE circuits individually so as to reduce power consumption of the whole system.Type: GrantFiled: January 10, 2012Date of Patent: October 9, 2012Assignee: Realtek Semiconductor Corp.Inventors: Der-Zheng Liu, Chung-Yao Chang, Kuang-Yu Yen
-
Publication number: 20120213104Abstract: A power adjusting apparatus communicating with a remote terminal is provided. The apparatus includes: a transceiving unit transmitting a plurality of test packets by a plurality of powers; a processing unit coupled to the transceiving unit, and deciding a transmission power for transmitting a subsequent packet according to at least one retransmission number of transmitting the test packets.Type: ApplicationFiled: February 14, 2012Publication date: August 23, 2012Applicant: REALTEK SEMICONDUCTOR CORP.Inventors: Wei-Hsuan Chang, Chung-Yao Chang, Der-Zheng Liu, Kuang-Yu Yen
-
Patent number: 8238465Abstract: A sphere decoding method applied to a MIMO channel is provided. Multiple constellation points of an nth detection layer corresponding to a MIMO channel matrix are enumerated based on an enumeration rule, and at least one nth sub-set of the nth detection layer is defined. K constellation points are obtained from each of the at least one nth sub-set as preferred points, and Kn preferred points are selected from all the K preferred points of the at least one nth sub-set. K1 preferred points are transferred to a second detection layer from a first detection layer. K(T?1) preferred points are transferred to a Tth detection layer from a (T?1)th detection layer. An optimal solution is determined according to Kn preferred points of the nth detection layer. K and at least one of K1 to KT are determined by the The characteristic of the MIMO channel matrix.Type: GrantFiled: September 18, 2009Date of Patent: August 7, 2012Assignee: Realtek Semiconductor Corp.Inventors: Yen-Chih Chen, Tsung-Chun Cheng, Der-Zheng Liu
-
Patent number: 8208575Abstract: A sphere decoding method applied to a MIMO channel is provided. T signals transmitted via the MIMO channel are received. A first triangular matrix corresponding to a channel matrix is generated and mapped from the complex domain into the real domain to obtain a second triangular matrix. A first zero-forcing soft-output solution corresponding to a first estimation layer is found, and multiple preferred points P(1) are obtained. Multiple n-th zero-forcing soft-output solutions corresponding to an n-th estimation layer are obtained according to multiple preferred points P(n?1), and multiple preferred points P(n) are obtained according to PEDs of multiple n-th constellation points. Multiple 2T-th zero-forcing soft-output solutions are obtained according to the preferred points P(2T?1) and multiple preferred points P(2T) are obtained correspondingly. The preferred point P(2T) corresponding to the least PED is mapped from the real domain into the complex domain to generate an optimal solution of the T signals.Type: GrantFiled: September 18, 2009Date of Patent: June 26, 2012Assignee: Realtek Semiconductor Corp.Inventors: Yen-Chih Chen, Tsung-Chun Cheng, Der-Zheng Liu
-
Patent number: 8184735Abstract: A sphere decoding method applied to a MIMO channel is provided. Multiple constellation points of an nth detection layer corresponding to the MIMO channel matrix are enumerated based on an enumeration rule, and at least one nth sub-set of the nth detection layer is defined. The constellation point with the least PED is obtained as a preferred point. Another constellation, not in the nth sub-set, of the nth detection layer is selected to substitute for the preferred point as one of the nth sub-set. If other preferred points are needed to be obtained, the nth sub-set is updated repeatedly according to the least PED. An optimal solution is determined according to Kn preferred points of the nth detection layer.Type: GrantFiled: September 18, 2009Date of Patent: May 22, 2012Assignee: Realtek Semiconductor Corp.Inventors: Yen-Chih Chen, Tsung-Chun Cheng, Der-Zheng Liu
-
Patent number: 8184749Abstract: A sphere decoding method applied to a MIMO channel is provided. Multiple constellation points of an nth detection layer corresponding to a MIMO channel matrix are enumerated based on an enumeration rule, and at least one nth sub-set of the nth detection layer is defined. The candidate range of the constellation points of the at least one nth sub-set is determined according to a predetermined number K of the preferred points of the at least one nth sub-set. K constellation points are obtained from the at least one nth sub-set as the preferred points according to partial Euclidean distances of the constellation points. The at least one nth sub-set includes at least K constellation points. Kn preferred points are selected from all K preferred points of the at least one nth sub-set. An optimal solution is determined according to the Kn, preferred points.Type: GrantFiled: September 18, 2009Date of Patent: May 22, 2012Assignee: Realtek Semiconductor Corp.Inventors: Yen-Chih Chen, Tsung-Chun Cheng, Der-Zheng Liu
-
Publication number: 20120108185Abstract: A multi-mode wireless transceiver and a multi-mode switching method thereof are disclosed to provide at least one wireless transceiving interface capable of dynamically switching between multiple frequency bands. The wireless transceiver comprises: a first RF transceiving circuit for transceiving RF signals of a first frequency band; a second RF transceiving circuit for transceiving RF signals of a second frequency band; a first frequency synthesizer and a second frequency synthesizer for generating a first carrier of the first frequency band and a second carrier of the second frequency band respectively; and a switching circuit for outputting the first carrier to the first RF transceiving circuit, and for determining to output one of the first and second carriers to the second RF transceiving circuit according to a control signal.Type: ApplicationFiled: May 4, 2011Publication date: May 3, 2012Applicant: REALTEK SEMICONDUCTOR CORP.Inventors: KUANG YU YEN, DER ZHENG LIU
-
Publication number: 20120108301Abstract: A multiple-antenna transceiver in the present invention includes a frame controller and circuitry for transmitting and receiving. The transmitting component includes a sequence selection circuit, a MIMO modulation and coding circuit, and numerous TX RFE and AFE circuits. The receiving component includes a MIMO demodulation and decoding circuit, a sequence separation circuit, and numerous RX RFE and AFE circuits. The frame controller can enable and disable the TX and RX RFE and AFE circuits individually so as to reduce power consumption of the whole system.Type: ApplicationFiled: January 10, 2012Publication date: May 3, 2012Applicant: REALTEK SEMICONDUCTOR CORP.Inventors: Der-Zheng Liu, Chung-Yao Chang, Kuang-Yu Yen
-
Publication number: 20120094622Abstract: An antenna diversity system having a non-interrupt function is provided. The antenna diversity system includes: a plurality of antennas, a plurality of radio frequency (RF) circuits, and a signal processing unit. The RF circuits are respectively coupled to the antennas, wherein each RF circuit is utilized for operating in one of a plurality of channels. The signal processing unit is coupled to the RF circuits, and utilized for determining whether a signal quality value of at least one of the antennas lower than a threshold to generate a determining result, and determining whether to change the channel of at least one of the RF circuits according to the determining result, so as to make at least two of the RF circuits operating in a same channel of the channels.Type: ApplicationFiled: October 18, 2011Publication date: April 19, 2012Inventors: Kuang-Yu Yen, Der-Zheng Liu
-
Publication number: 20120087431Abstract: The present invention provides an antenna diversity apparatus and an antenna diversity method. The antenna diversity apparatus comprises: a plurality groups of antennas, a switching unit, a demodulating unit, an antenna switch selecting unit, and a control unit, wherein each group of the plurality groups of antennas comprises at least an antenna, and the control unit can comprises: a receiving signal quality detecting unit, a packet detecting unit, and an antenna decision unit. The antenna decision unit can be realized by hardware, firmware, or software, and the antenna switch selecting unit can be realized by hardware. The antenna diversity apparatus and the antenna diversity method provided by the present invention can switch antennas fast to avoid the defect of occurring burst error to reduce transmitting data rate, and switch to proper antennas fast when variation of the data transmission channels occurs.Type: ApplicationFiled: October 2, 2011Publication date: April 12, 2012Inventors: Der-Zheng Liu, Yung-Ting Chen, Kuang-Yu Yen