Patents by Inventor Jianhan Liu

Jianhan 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: 10003488
    Abstract: The present invention provides a method and an electronic apparatus for automatically detecting bandwidth and the packet type of a packet, so as to solve the problem mentioned above. The method comprises: detecting a plurality of symbols in the preamble of the packet; generating a sign pattern according to the symbols; and determining the bandwidth and the packet type of the packet according to the detected sign pattern. The electronic apparatus comprises: a symbol detecting circuit, a sign pattern generating circuit, and a determining circuit. The symbol detecting circuit is utilized for detecting a plurality of symbols in the preamble of the packet. The sign pattern generating circuit is utilized for generating a sign pattern according to the symbols. The determining circuit is utilized for determining the bandwidth and the packet type of the packet according to the detected sign pattern.
    Type: Grant
    Filed: March 4, 2016
    Date of Patent: June 19, 2018
    Assignee: MEDIATEK INC.
    Inventors: Chien-Fang Hsu, Jianhan Liu
  • Patent number: 9992797
    Abstract: A method to improve channel access opportunity for wide bandwidth transmission in wireless local area networks is proposed. The method allows different clear channel assessment (CCA) thresholds for different transmission channel bandwidth. During a primary channel CCA process, a low CCA threshold level is applied for an intended narrow transmission channel bandwidth, while a high CCA threshold level is applied for an indented wide transmission channel bandwidth. In addition to the “all bandwidth transmission branch” that is based on the low CCA level, the “wide bandwidth transmission branch” is based on the high CCA level, which increases the opportunity for channel access by raising the CCA levels based on intended transmission channel bandwidths. As a result, the likelihood of wide channel transmission is increased.
    Type: Grant
    Filed: January 14, 2016
    Date of Patent: June 5, 2018
    Assignee: MediaTek Singapore Pte Ltd.
    Inventors: Jianhan Liu, James June-Ming Wang
  • Publication number: 20180131469
    Abstract: Systems and methods of expanding indication capabilities of existent PPDU preamble fields. The “GI+LTF Size” field is redefined to indicate a new combination of GI duration and HE-LTF size. The redefinition is indicated when the values of the two other existent fields, in combination, indicate an invalid scenario because the two values should have been mutually exclusive. Particularly, the DCM field and the STBC field are both set to the “enabled” mode as an indication for redefine the “GI+LTF Size” field. Upon receiving such a PPDU, a receiver is configured to resolve the PPDU as neither DCM nor STBC is enabled. Rather, the receiver interprets the particular combination of DCM and STBC values as an indication that the “GI+LTF Size” field is redefined to indicate the new combination of GI duration and HE-LTF size.
    Type: Application
    Filed: October 26, 2017
    Publication date: May 10, 2018
    Inventors: Jianhan LIU, Tianyu WU, Shengquan HU, Thomas Edward PARE, JR.
  • Patent number: 9954594
    Abstract: A method of channel estimation enhancement is provided. In a wireless communications system, a transmitting device transmits a long preamble frame comprising a first training field, a signal field, and a second training field. The signal field has a beam-change indicator bit indicates whether there is beam change between the first training field and the second training field. A receiving device receives the long preamble frame, performs a first channel estimation based on the first training field, and performs a second channel estimation based on the second training field. If the beam-change indicator bit indicates negative beam change, then the receiving device performs channel estimation enhancement by combining the first channel estimation and the second channel estimation. As a result, channel estimation performance is improved.
    Type: Grant
    Filed: March 7, 2016
    Date of Patent: April 24, 2018
    Assignee: MEDIATEK Singapore Pte. Ltd.
    Inventors: Jianhan Liu, Thomas Edward Pare, Jr., Chao-Chun Wang, James June-Ming Wang, YungPing Hsu
  • Patent number: 9941940
    Abstract: A communication method for a wireless network is disclosed. The wireless network comprises a plurality of wireless devices. The method comprises transmitting one or multiple packets with an omni-beam by a first wireless device to a second wireless device in a packet exchange during an omni-beam duration to indicate a sectorized-beam duration, receiving the packet(s) by a third wireless device, transmitting/receiving data by the first wireless device using a sectorized beam in a packet exchange with the second wireless device during the sectorized beam duration, and detecting by the third wireless device the sectorized beam packet(s) from the first wireless device and packet(s) from the second wireless device, if no sectorized beam packet(s) from the first wireless device and packet(s) from the second wireless device is detected, the third wireless device starting to communicating with a fourth wireless device.
    Type: Grant
    Filed: July 10, 2013
    Date of Patent: April 10, 2018
    Assignee: MediaTek Singapore Pte. Ltd.
    Inventors: James June-Ming Wang, Jianhan Liu, Yung-Ping Hsu, Chih-Shi Yee, Chao-Chun Wang, Vishakan Ponnampalam
  • Patent number: 9923702
    Abstract: A method of downlink multi-sector transmission is provided. An initiator station first performs sector training by transmitting a plurality of sounding signals to a plurality of responder stations in a wireless network. The coverage associated with the initiator station is partitioned into a plurality of sectors, and each sector is covered by a sectorized beam. The initiator station then receives sector ID feedback information from each responder station in response to the sounding signals. The sector ID feedback information indicates preference to each of the sectors from each responder station. Next, the initiator station groups multiple spatially orthogonal responder stations together based on the sector ID feedback information. Finally, the initiator station performs multi-sector transmission by simultaneously transmitting data to the multiple responder stations in different sectors using corresponding sectorized beams.
    Type: Grant
    Filed: January 23, 2014
    Date of Patent: March 20, 2018
    Assignee: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: James June-Ming Wang, Jianhan Liu, Yung-Ping Hsu, Chih-Shi Yee
  • Publication number: 20180062787
    Abstract: A wireless communicating method includes: performing one resource unit allocation upon a channel; and allocating a first resource unit and a second resource unit in said one resource unit allocation to a station, wherein the first resource unit is different from the second resource unit. By using the wireless communication method, throughput rate can be improved.
    Type: Application
    Filed: August 23, 2017
    Publication date: March 1, 2018
    Inventors: Hung-Tao Hsieh, Tung Sheng Yang, Hsuan-Yu Liu, Kun-Chien Hung, YungPing Hsu, Jianhan Liu, Shengquan Hu, Chih-Shi Yee, Thomas Edward Pare, JR.
  • Patent number: 9883547
    Abstract: A communication method that operates by determining a first set of physical parameters of a first channel by a coordinator in a wireless communication system; establishing communication with a first set of devices over the first channel; determining a protection period in accordance with a pre-determined rule; broadcasting a channel-adjustment message, wherein the channel-adjustment message comprises a set of instructions for indicating how to adjust from the first channel to a second channel, and the set of instructions comprise channel bandwidth information for indicating how to adjust to a bandwidth of the second channel and central frequency information for indicating how to adjust to a central frequency of the second channel; and communicating with a second set of devices over the second channel during the protection period.
    Type: Grant
    Filed: January 19, 2017
    Date of Patent: January 30, 2018
    Assignee: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: Chao-Chun Wang, Jianhan Liu, Chih-Shi Yee, Huanchun Ye, James June-Ming Wang
  • Publication number: 20170347234
    Abstract: An emergency mode is provided in a portable electronic device for locating a survivor in a disaster. The device includes a wireless antenna to transmit and receive wireless signals; a memory to store one or more identifiers; a user interface to receive a command that enables the emergency mode. The device also includes one or more processors, which, in response to the command, detect via the wireless receiver a predetermined identifier that matches a stored identifier identifying a sender of the predetermined identifier as a trusted node. When the predetermined identifier and a timing measurement frame are received from the trusted node, the device sends a response to the trusted node to indicate its presence.
    Type: Application
    Filed: March 27, 2017
    Publication date: November 30, 2017
    Inventors: Chuen-Shen Bernard Shung, Jianhan Liu, George Chien, YungPing Hsu, Yasantha Rajakarunanayake, Dingchung Jann, Tom Hsiou-Cheng Kao
  • Publication number: 20170332241
    Abstract: A backward compatible frame reuse mechanism that allows new information to be defined a reused frame without causing any incorrect operation in a legacy receive device. To generate a reused frame, a portion of the frame in the first format is masked with a predetermined masking sequence (PMS) and thereby redefined as new fields in a second format. When a device that supports the reuse scheme receives a frame that possible is a reused frame, the device checks the potentially reused portion according to the first format after de-masking and also checks according to the second format without de-masking. Based on the check results, the device selects a format to resolve the frame. A legacy device receiving the reused frame only checks the reused portion without de-masking, which results in a certain check error and makes the device discard the frame without any harmful operation.
    Type: Application
    Filed: May 9, 2017
    Publication date: November 16, 2017
    Inventors: Jianhan Liu, Tianyu Wu, Rongsheng Huang, James June-Ming Wang
  • Patent number: 9820162
    Abstract: A method of spatial re-use with TPC and adaptive CCA is proposed. A spatial re-use station detects spatial re-use information associated with other peer OBSS stations. The spatial re-use information comprises a TX spectral density (power/Hz) and received signal or interference information of each inter-BSS peer station. The spatial re-use STA determines a TX spectral density based on the detected spatial re-use information. The spatial re-use STA then contends the medium for spatial re-use transmission opportunity (TXOP) with an intra-BSS peer station. Finally, the spatial re-use STA starts spatial re-use frame exchange with the intra-BSS peer station using the determined TX spectral density. By adjusting the TX spectral density, the spatial re-use STA adapts its CCA level to spatially reuse the medium without causing collision and interference to OBSS stations and thus increases network throughput.
    Type: Grant
    Filed: February 9, 2016
    Date of Patent: November 14, 2017
    Assignee: MEDIATEK SINGAPORE PTE LTD.
    Inventors: James June-Ming Wang, Jianhan Liu, YungPing Hsu, Ching-Hwa Yu
  • Publication number: 20170317727
    Abstract: System and method of Multi-User Multiple-Input Multiple-Output (MU-MIMO) Beamforming communication. An MU-MIMO BF training session is used to train all the responders in a user group in relation to an initiator having multiple antenna arrays. Accordingly, suitable TX-RX sector pairs are selected based on the training results, and the user group is arranged into subsets such that the initiator can transmit data to the responders in one subset simultaneously by using mutually orthogonal BF waveforms. Prior to the MU-MIMO BF training session, the initiator can select TX sectors of the TX antennas and responders for the training session based on results from a prior or preliminary SISO BF training.
    Type: Application
    Filed: April 27, 2017
    Publication date: November 2, 2017
    Inventors: James June-Ming Wang, Jianhan Liu
  • Patent number: 9780926
    Abstract: Methods and apparatus are provided for burst OFDMA support MU-MIMO in the WLAN network. In one novel aspect, pluralities of user channels are configured for a downlink wideband channel, wherein each user channel is associated with a user group selecting from a SU-SISO, or a SU-MIMO or a MU-MIMO. In one embodiment, the SIG1 and SIG2 signaling fields are independent for each user channel. In another embodiment, the SIG1 fields are duplicates for all user channels carrying common information. The SIG2 fields for each user group are different from each other carrying user group specific information. In another novel aspect, an uplink OFDMA frames contains ACK packets from multiple STAs concurrently using an uplink wideband channel. In one embodiment, one ACK packet is sent for a MU-MIMO user group. In another embodiment, the uplink ACK packet assignment is based on indications in the downlink PHY SIG field.
    Type: Grant
    Filed: August 22, 2015
    Date of Patent: October 3, 2017
    Assignee: MEDIATEK INC.
    Inventors: Yuh-Ren Jauh, Jianhan Liu, Chao-Chun Wang, James June-Ming Wang, Thomas Edward Pare, Jr.
  • Patent number: 9749967
    Abstract: A method of spatial reuse with opportunistic transmit power control (TPC) and clear channel assessment (CCA) is proposed. In the opportunistic TPC and CCA, a spatial reuse station (SR-STA) gains enough knowledge in certain situation for more aggressive spatial reuse such that its transmit power may be adjusted to meet the spatial reuse conditions based on the received OBSS PPDU and the corresponding spatial reuse parameter (SRP). Both Type 1 SRP and Type 2 SRP are defined. In one example, the Type 1 or Type 2 SRP is a 5-bit parameter carried in the HE-SIG-A field of the OBSS PPDU, which can be a trigger frame, a response frame, a request-to-send (RTS)/clear-to-send (CTS) frame, and a data frame.
    Type: Grant
    Filed: September 6, 2016
    Date of Patent: August 29, 2017
    Assignee: MEDIATEK INC.
    Inventors: James June-Ming Wang, Jianhan Liu, Chao-Chun Wang, YungPing Hsu
  • Publication number: 20170230220
    Abstract: Dual sub-carrier modulation (DCM) is introduced in high efficiency (HE) WLAN. DCM is a solution to deal with narrow band interferences and for range extension. DCM can introduce frequency diversity into OFDM systems by transmitting the same information on two subcarriers separated in frequency. If DCM is applied, then the transmitter modulates the same encoded bits onto two separated subcarriers with the same or different constellation mapping schemes. DCM suffers from a high peak-to-average power ratio (PAPR). In accordance with one novel aspect, a method of transmitting and encoding a HE PPDU frame with binary phase shift keying (BPSK) DCM and lower PAPR is proposed.
    Type: Application
    Filed: February 2, 2017
    Publication date: August 10, 2017
    Inventors: Gary A. Anwyl, Jianhan Liu, Tianyu Wu, Thomas Edward PARE, JR.
  • Patent number: 9717022
    Abstract: A method of reducing the usable channel bandwidth and increasing the channel bandwidth at run time is provided. The method allows a receiving wireless communications device to inform its corresponding transmitting communications device to either increase, reduce, or maintain the number of usable narrow band channels for the succeeding frame exchange. In a wireless communications channel, channel reduction is accomplished by using a usable channel indicator in a response frame responding to the preceding receiving frame. The usable channel indicator is the means for the receiving communications device to inform the transmitting communications device the preferred narrow band channels that it deems having good channel characteristics.
    Type: Grant
    Filed: December 12, 2013
    Date of Patent: July 25, 2017
    Assignee: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: Chao-Chun Wang, Chih-Shi Yee, Jianhan Liu
  • Publication number: 20170180177
    Abstract: A method of interleaver design for dual carrier modulation (DCM) is proposed in a wireless network. For HE PPDU transmission with DCM, information bits are first encoded by a BCC encoder. The BCC encoded bit streams are then interleaved by a BCC interleaver. More specifically, the BCC interleaved bits are repeated on two halves of a given resource unit (RU). The BCC interleaver parameters are defined based on half of the total number of the data tones of the RU if DCM is applied. The BCC interleaved bits are then modulated and mapped to two halves of the RU by a DCM constellation mapper.
    Type: Application
    Filed: December 16, 2016
    Publication date: June 22, 2017
    Inventors: Tianyu Wu, Jianhan Liu, Gary A. Anwyl, Thomas Edward PARE, JR.
  • Publication number: 20170171796
    Abstract: A method of very high throughput (VHT) operation information subfields design for IEEE 802.11 WLAN is proposed. The VHT operation information subfields comprise a channel width, a channel center frequency segment 0 (CCFS0), and a channel center frequency segment 1 (CCFS1). Multiple definitions of the VHT operation information subfields have been adopted by different access points (AP)s and wireless stations (STAs). In accordance with one novel aspect, upon receiving the VHT operation information element broadcasted by an AP, an STA will first check the channel width indicated by the AP. The STA then follows different definitions under different channel widths. Under such method, the STA can support up to 160 MHz operation mode with APs following different definitions and operating up to 160 MHz mode.
    Type: Application
    Filed: December 8, 2016
    Publication date: June 15, 2017
    Inventors: TIANYU WU, CHAO-CHUN WANG, CHIEN-FANG HSU, JAMES JUNE-MING WANG, JIANHAN LIU, THOMAS EDWARD PARE, JR.
  • Patent number: 9673956
    Abstract: A spatial reuse prioritized channel access scheme is proposed to enhance the average throughput per station in a wireless network by optimizing spatial reuse. Spatial reuse capability (SRC) is defined as a monotonically decreasing function of co-channel interference signal strength from OBSSs. Higher spatial reuse capability can be transformed into higher data rate or less usage of airtime by using higher MCS or less interferences to OBSSs by reducing TX power. By allowing the stations that have larger spatial reuse capability to have higher probability to win channel access contention, the overall network throughput is enhanced.
    Type: Grant
    Filed: August 28, 2015
    Date of Patent: June 6, 2017
    Assignee: MEDIATEK INC.
    Inventors: Jianhan Liu, Tianyu Wu, Rongsheng Huang, James June-Ming Wang
  • Publication number: 20170135148
    Abstract: A communication method that operates by determining a first set of physical parameters of a first channel by a coordinator in a wireless communication system; establishing communication with a first set of devices over the first channel; determining a protection period in accordance with a pre-determined rule; broadcasting a channel-adjustment message, wherein the channel-adjustment message comprises a set of instructions for indicating how to adjust from the first channel to a second channel, and the set of instructions comprise channel bandwidth information for indicating how to adjust to a bandwidth of the second channel and central frequency information for indicating how to adjust to a central frequency of the second channel; and communicating with a second set of devices over the second channel during the protection period.
    Type: Application
    Filed: January 19, 2017
    Publication date: May 11, 2017
    Inventors: Chao-Chun WANG, Jianhan LIU, Chih-Shi YEE, Huanchun YE, James June-Ming WANG