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).

  • Publication number: 20160261434
    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: Application
    Filed: March 4, 2016
    Publication date: September 8, 2016
    Inventors: Chien-Fang Hsu, Jianhan Liu
  • Publication number: 20160248542
    Abstract: A novel feedback schemes are introduced to assistant link adaptation for re-transmissions and to improve the network throughput and efficiency. When reception failure is a type B failure, then a failure report (FR) frame is feedback from the destination STA to the source STA. In the failure report frame, link adaptation information and information on failure causes are included.
    Type: Application
    Filed: May 5, 2016
    Publication date: August 25, 2016
    Inventors: Jianhan Liu, Chao-Chun Wang, Thomas Edward PARE, JR., YungPing Hsu
  • Publication number: 20160191136
    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: Application
    Filed: March 7, 2016
    Publication date: June 30, 2016
    Inventors: Jianhan Liu, Thomas Edward PARE, JR., Chao-Chun Wang, James June-Ming Wang, YungPing Hsu
  • Publication number: 20160183305
    Abstract: A method of improved allocation of uplink resources in an OFDMA network is proposed. A wireless communications station (an AP) reserves both dedicated resource and contention resource for uplink OFDMA operation for a list of communications devices (STAs). The AP can switch between random access operation and non-random access operation without the need for any special protection mechanisms. In the event of an increase in uplink OFDMA frame collisions the AP can switch from random operation to non-random operation to reduce the number of collisions. In the event of a decrease in uplink OFDMA frame collisions the AP can switch from non-random operation to random operation to reduce required AP processing. The AP can also dynamically control a STA access probability to reduce the number of collisions by reducing the number of uplink OFDMA frames each STA transmits.
    Type: Application
    Filed: December 21, 2015
    Publication date: June 23, 2016
    Inventors: RONGSHENG HUANG, Tianyu Wu, Jianhan Liu, Chao-Chun Wang, Chih-Shi Yee
  • Publication number: 20160174079
    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: Application
    Filed: February 9, 2016
    Publication date: June 16, 2016
    Inventors: James June-Ming Wang, Jianhan Liu, YungPing Hsu, Ching-Hwa Yu
  • Publication number: 20160174253
    Abstract: A method to improve the area throughput of dense wireless local area networks (WLAN) by channel access control is proposed. The method allows an access point to obtain information of a plurality of stations within the wireless network. The access point classifies the plurality of stations into at least one group of stations and assigns a group identification (ID) according to the obtained information. The group ID and channel access control parameters are sent to the stations that are classified into the certain group. The stations in each of the group use the received channel access control parameters to communicate with the access point.
    Type: Application
    Filed: July 13, 2014
    Publication date: June 16, 2016
    Inventors: Jianhan Liu, James June-Ming Wang, Thomas Edward Pare, JR., Yung-Ping Hsu
  • Publication number: 20160157264
    Abstract: A method of channel contention procedure with CCA level enhancement is proposed. A wireless device initiates an EDCA channel contention procedure to gain access to the wireless medium. The device determines an intended TX channel width and performs primary channel CCA using a set of CCA levels based on the intended TX channel width for determining channel idle or busy condition in the EDCA procedure. Upon gaining access, the device performs secondary channel CCA and thereby determining a final TX channel width. The device transmits radio signals using the final TX channel width and a TX spectral power density, which is adjusted to be corresponding to the intended TX channel width. By raising CCA levels to be based on the intended transmission channel width, the likelihood of wide channel width transmission is increased. As a result, significant network throughput increase can be accomplished in dense deployment scenarios.
    Type: Application
    Filed: December 24, 2015
    Publication date: June 2, 2016
    Inventors: James June-Ming Wang, Jianhan Liu, YungPing Hsu
  • Publication number: 20160128099
    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: Application
    Filed: January 14, 2016
    Publication date: May 5, 2016
    Inventors: Jianhan Liu, James June-Ming Wang
  • Publication number: 20160112107
    Abstract: A method of enhanced beamforming procedure to achieve spatial reuse and thereby improving cell edge performance and area throughput is proposed. The enhanced beamforming method increases the likelihood of channel access under dense deployment condition, reduces interference to OBSS, reduces collision during reception, and increases the likelihood of spatial reuse in dense deployment scenario thus leading to higher network throughput.
    Type: Application
    Filed: December 27, 2015
    Publication date: April 21, 2016
    Inventors: James June-Ming Wang, Jianhan Liu, Thomas Edward PARE, JR., Chao-Chun Wang, Chih-Shi Yee, YungPing Hsu
  • Patent number: 9319896
    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: May 2, 2013
    Date of Patent: April 19, 2016
    Assignee: MEDIATEK Singapore Ple. Ltd.
    Inventors: Jianhan Liu, Thomas Edward Pare, Chao-Chun Wang, James June-Ming Wang, YungPing Hsu
  • Publication number: 20160066257
    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: Application
    Filed: August 28, 2015
    Publication date: March 3, 2016
    Inventors: Jianhan Liu, Tianyu Wu, Rongsheng Huang, James June-Ming Wang
  • Publication number: 20160065467
    Abstract: A method of providing a configurable signaling (SIG) field is proposed to reduce the SIG overhead of a data packet in a wireless network. The SIG field comprises both HE-SIG-A field and HE-SIG-A2 field. HE-SIG-A field contains only necessary information for a default network scenario (e.g., indoor non-OFDMA SU-MIMO) to avoid HE-SIG-A2. HE-SIG-A2 field contains OFDMA, MU-MIMO, and/or outdoor parameter settings. By using HE-SIG-A to indicate the existence, mode, and/or length of HE-SIG-A2, the signaling overhead for default scenario can be reduced by avoiding the entire HE-SIG-A2 field. The number of symbols required for HE-SIG-A2 is adjustable based on each transmission scenario and indicated by HE-SIG-A. Further, because higher MCS such as QPSK may be supported for HE-SIG-A2, additional signaling overhead is reduced.
    Type: Application
    Filed: August 27, 2015
    Publication date: March 3, 2016
    Inventors: Tianyu Wu, Jianhan Liu, Thomas Edward Pare, JR.
  • Publication number: 20160050691
    Abstract: Methods and apparatus are provided for clear channel assessment in the Wifi network. In one novel aspect, different clear channel assessment (CCA) threshold value is set for intra-BSS and inter-BSS frames during the counting down process. A CCA procedure senses the radio channel and determines if the radio channel is busy or idle during the backoff period by comparing the signal level value of detected fames with the CCA threshold value. The counting down will be suspended if the radio channel determined to be busy. If the detected frame is inter-BSS frame, the CCA threshold value is raised. If the signal level of the detected frames is lower than the inter-BSS CCA threshold for inter-BSS fames, the radio channel is considered idle. The counting down process is resumed.
    Type: Application
    Filed: August 12, 2015
    Publication date: February 18, 2016
    Inventors: Yuh-Ren Jauh, James June-Ming Wang, Chao-Chun Wang, Ching-Hwa Yu, Jianhan Liu
  • Patent number: 9258070
    Abstract: A method of simultaneously providing channel quality feedback information in all valid sub-channels is provided to facilitate and improve the performance of dynamic transmission bandwidth adjustment and fast link adaptation. A receiving device receives a sounding signal over a wide channel in a wireless system. The sounding signal is transmitted from a transmitting device over multiple sub-channels of the wide channel. The receiving device estimates channel quality information based on the sounding signal for each sub-channel. The channel quality information includes estimated average SNR and recommended MCS and other channel quality metrics. The receiving device transmits a feedback message to the transmitting device. The feedback message contains the estimated channel quality information for all valid sub-channels within the transmission bandwidth.
    Type: Grant
    Filed: October 20, 2011
    Date of Patent: February 9, 2016
    Assignee: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: James June-Ming Wang, Vishakan Ponnampalam, Jianhan Liu, Chao-Chun Wang, Huanchun Ye
  • Patent number: 9253619
    Abstract: The method and apparatus of data communications for a transmitter in a millimeter wave network are provided. The method includes: generating a control physical layer (CPHY) preamble; generating a header, wherein the header includes a mode indicator; modulating and encoding a payload according to the mode indicator; generating a packet according to the control physical layer (CPHY) preamble, the header and the payload; and transmitting the packet.
    Type: Grant
    Filed: September 6, 2013
    Date of Patent: February 2, 2016
    Assignee: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: Jianhan Liu, James June-Ming Wang, Chi-Shi Yee, Thomas Edward Pare, Jr., YungPing Hsu
  • Patent number: 9246571
    Abstract: The disclosed invention provides an efficient method for beam training to enable spatial multiplexing MIMO operation and spatial combining in a wireless network. The invention discloses a simple and efficient beam-training algorithm and protocol for MIMO operation that operates in high SNR condition for reliable MIMO operation. In one novel aspect, the best MIMO beam combinations are determined after TX sector sweeping and RX sector sweeping. In addition, the selection criteria includes not only signal quality, but also considers mutual interference and leakage among multiple MIMO spatial streams to improve overall MIMO performance.
    Type: Grant
    Filed: April 29, 2015
    Date of Patent: January 26, 2016
    Assignee: MEDIATEK SINGAPORE PTE. LTD.
    Inventors: James June-Ming Wang, Vishakan Ponnampalam, Jianhan Liu, Chao-Chun Wang, Chi-Shi Yee, YungPing Hsu
  • Publication number: 20160014763
    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: Application
    Filed: August 22, 2015
    Publication date: January 14, 2016
    Inventors: Yuh-Ren Jauh, Jianhan Liu, Chao-Chun Wang, James June-Ming Wang, Thomas Edward PARE, JR.
  • Publication number: 20160006554
    Abstract: Methods and apparatus are provided for a many to one communication protocol. In one novel aspect, a modified CTS is sent by a receiving wireless communications station in response to a regular RTS. The modified CTS includes an indication for an uplink MU operation. In one embodiment, a modified CTS indicates a restricted access window (RAW) followed by RAW parameter set (RPS). In one embodiment, a subset of wireless communications devices associated with the receiving wireless communications station sends modified PS-poll with uplink data indication. Such PS-poll traffic is protected from passerby wireless communications devices from an OBSS. The receiving wireless communications station sends a modified resource-allocation map frame followed by a regular CTS frame. The subsets of wireless communications devices send their uplink data based on the received resource allocation map.
    Type: Application
    Filed: June 30, 2015
    Publication date: January 7, 2016
    Inventors: Chao-Chun Wang, Jianhan Liu, Tianyu Wu, Rongsheng Huang
  • Publication number: 20150372795
    Abstract: A method of indicating feedback mode and providing corresponding sub-channel feedback in OFDMA systems is provided. A transmitting device transmits a sounding announcement frame and a sounding signal to a receiving device. The sounding signal is transmitted over multiple sub-channels of a wide channel. The transmitting device also provides a feedback mode indication. The receiving device estimates channel quality information based on the received sounding signal and the feedback mode indication. The receiving device then sends feedback information to the transmitting device. The feedback information contains the estimated channel quality information of a selected set of sub-channels based on the feedback mode indication.
    Type: Application
    Filed: June 17, 2015
    Publication date: December 24, 2015
    Inventors: Tianyu Wu, Jianhan Liu, Thomas Edward Pare, JR.
  • Publication number: 20150333894
    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: Application
    Filed: January 23, 2014
    Publication date: November 19, 2015
    Inventors: James June-Ming WANG, Jianhan LIU, Yung-Ping HSU, Chih-Shi YEE