Patents by Inventor Narayan Prasad

Narayan Prasad 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: 9450655
    Abstract: Methods are provided. A method includes determining respective weighted likelihoods corresponding to a plurality of users in a multiple-input multiple-output communication system. The method further includes forming a plurality of user groups from the plurality of users using an iterative K-means clustering technique applied to the plurality of users. The iterative K-means clustering technique is responsive to the respective weighted likelihoods.
    Type: Grant
    Filed: September 25, 2014
    Date of Patent: September 20, 2016
    Assignee: NEC Corporation
    Inventors: Narayan Prasad, Sampath Rangarajan, Guosen Yue, Yi Xu
  • Publication number: 20160248492
    Abstract: A method implemented in a base station used in a wireless communications system is disclosed. The method comprises having 1-layer, 2-layer, 3-layer, and 4-layer codebooks for 4 transmit antenna (4TX) transmission, each codebook including a plurality of precoding matrices, (precoding data with one of the plurality of precoding matrices, and transmitting, to a user equipment, the precoded data, wherein each of the 1-layer and 2-layer codebooks comprises a first codebook and a second codebook, and wherein each precoding matrix in the first codebook comprises a first index and a second index. Other apparatuses, systems, and methods also are disclosed.
    Type: Application
    Filed: May 2, 2016
    Publication date: August 25, 2016
    Inventors: Narayan PRASAD, Guosen Yue, Mohammad Khojastepour, Sampath Rangarajan
  • Patent number: 9424127
    Abstract: Aspects of charger detection and optimization prior to host control are described herein. In various embodiments, a condition of whether reverse current is present on a system bus is detected. When the condition for reverse current is present, reverse current is sunk by one or more of various reverse current sink circuits. By relying upon one or more of the reverse current sink circuits, for safety, to address or mitigate the condition for reverse current, a detector may be able to identify or distinguish among several different types of charger or charging ports coupled to a system bus allowing a charger to be selected optimally. Further, an indicator of the type of charger or charging port coupled to the system bus is communicated over a single pin interface, for backwards compatibility with circuits capable of identifying between only two different types of chargers.
    Type: Grant
    Filed: July 25, 2013
    Date of Patent: August 23, 2016
    Assignee: BROADCOM CORPORATION
    Inventors: Walid Nabhane, Mark D Rutherford, Narayan Prasad Ramachandran, David Chang, Yi Ting Chen, Chenmin Zhang, Ajmal A. Godil
  • Patent number: 9420493
    Abstract: At a coarse time-scale, at the start of each frame the choice of TPs to be made active and users to associate with the active TPs are determined by solving an optimization problem. The inputs to the optimization problem are averaged slowly varying metrics that are relevant for a period longer than the backhaul latency. At a the fine time-scale, in each slot each active TP independently does scheduling over the set of users associated with it, without any coordination with any of the other active TPs, based on fast changing information, such as instantaneous rate or SINR estimates.
    Type: Grant
    Filed: September 28, 2014
    Date of Patent: August 16, 2016
    Assignee: NEC Corporation
    Inventors: Narayan Prasad, Mustafa Arslan, Sampath Rangarajan
  • Publication number: 20160233994
    Abstract: A method and transmitting device are provided for coordinated multi-point transmission scheduling by a transmitting device over one or more heterogeneous wireless networks that include a set of clusters. Each of the clusters has a set of transmission points for serving a set of user equipment devices. The method includes determining constraints imposed on any of the user equipment devices. The method further includes receiving channel state information feedback from the user equipment devices. The method also includes obtaining user weights and buffer sizes. The method additionally includes iteratively determining a weighted sum of user rates based on the constraints, the channel state information feedback, the user weights, and the buffer sizes. The iteratively determining step determines the weighted sum of user rates based on an initial weighted sum of user rates determined for the user equipment devices without the constraints.
    Type: Application
    Filed: February 4, 2016
    Publication date: August 11, 2016
    Inventors: Narayan Prasad, Sampath Rangarajan, Yasushi Maruta, Duong Pham, Arun Gurung, Caroline Liang, Patricia Wells, Robert Arnott
  • Patent number: 9385899
    Abstract: A method implemented in a base station used in a wireless communications system is disclosed. The method comprises having 1-layer, 2-layer, 3-layer, and 4-layer codebooks for 4 transmit antenna (4TX) transmission, each codebook including a plurality of precoding matrices, precoding data with one of the plurality of precoding matrices, and transmitting, to a user equipment, the precoded data, wherein each of the 1-layer and 2-layer codebooks comprises a first codebook and a second codebook, and wherein each precoding matrix in the first codebook comprises a first index and a second index. Other apparatuses, systems, and methods also are disclosed.
    Type: Grant
    Filed: March 11, 2014
    Date of Patent: July 5, 2016
    Assignee: NEC Corporation
    Inventors: Narayan Prasad, Guosen Yue, Mohammad Khojastepour, Sampath Rangarajan
  • Patent number: 9337906
    Abstract: A method implemented in a user equipment (UE) used in an orthogonal frequency division multiple access (OFDMA) wireless communications system supporting coordinated multi-point (CoMP) joint transmission (JT) is disclosed. The method includes measuring reference signal received power (RSRP), transmitting, to a network, first feedback on the RSRP, receiving, from the network, a CoMP measurement set, conducting pre-scheduling CoMP UE fallback according to the CoMP measurement set, computing channel quality and direction information according to a UE category, and transmitting, to the network, second feedback on the channel quality and direction information. Other methods, apparatuses, and systems also are disclosed.
    Type: Grant
    Filed: March 18, 2013
    Date of Patent: May 10, 2016
    Assignee: NEC Corporation
    Inventors: Narayan Prasad, Guosen Yue, Sampath Rangarajan, Meilong Jiang
  • Publication number: 20160094320
    Abstract: In a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the first base station supporting coordinated multi-point transmission and reception (CoMP) is disclosed. The wireless communications method comprises receiving from the second base station an information element (IE) indicating multiple relative narrowband Tx (transmit) power (RNTP) thresholds, and performing interference aware scheduling. Other methods, systems, and apparatuses also are disclosed.
    Type: Application
    Filed: September 16, 2015
    Publication date: March 31, 2016
    Inventors: Narayan Prasad, Mohammad Khojastepour, Sampath Rangarajan
  • Publication number: 20160094321
    Abstract: In a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the first base station supporting coordinated multi-point transmission and reception (CoMP) is disclosed. The wireless communications method comprises receiving, from the second base station, a user equipment (UE) identification (ID) for a UE in a reference signal received power (RSRP) report, and using the UE ID to link the RSRP report with another measurement result for the UE. Other methods, systems, and apparatuses also are disclosed.
    Type: Application
    Filed: September 16, 2015
    Publication date: March 31, 2016
    Inventors: Narayan Prasad, Mohammad Khojastepour, Sampath Rangarajan
  • Publication number: 20160094279
    Abstract: In a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the first base station supporting coordinated multi-point transmission and reception (CoMP) is disclosed. The wireless communications method comprises, for a given user equipment (UE) identification (ID) and a given channel state information (CSI) process, receiving from the second base station a plurality of CSI reports each of which comprises a rank indication (RI) and a channel quality indicator (CQI), wherein the second base station receives from one or more user equipments (UEs) RI and CQI information. Other methods, systems, and apparatuses also are disclosed.
    Type: Application
    Filed: September 16, 2015
    Publication date: March 31, 2016
    Inventors: Narayan Prasad, Mohammad Khojastepour, Sampath Rangarajan
  • Publication number: 20160037387
    Abstract: A system and method for resource management in a heterogeneous wireless network wherein the resources of the mobile communications system are managed on a coarse time-scale and a fine time-scale. The coarse time-scale management comprises a first stage of determining the user association for each of the plurality of TPs followed by a second stage of determining activation fractions for all TPs. The determining of the user association is performed by utilizing a GLS procedure having a Greedy Stage and a Local Search Stage. In the Greedy Stage, new user, TP pairs are analyzed and the pair with the greatest improvement in system utility is selected. In the Local Search Stage, potential swaps are analyzed and a pair offering the greatest improvement that exceeds a threshold is selected. The determining of activation fractions for all TPs is performed by utilizing an auxiliary function method.
    Type: Application
    Filed: July 29, 2015
    Publication date: February 4, 2016
    Inventors: Narayan Prasad, Vaibhav Singh, Sampath Rangarajan
  • Publication number: 20160037535
    Abstract: A system and method for resource management in a heterogeneous wireless network that is performed via distributed implementation wherein the resources of the mobile communications system are managed on a coarse time-scale and a fine time-scale. The coarse time-scale management comprises a first stage of determining the user association for each of the TPs followed by a second stage of determining activation fractions for all TPs. The determining of the user association is performed by utilizing a GLS procedure having a Greedy Stage and a Local Search Stage. In the Greedy Stage, new user, TP pairs are analyzed and the pair with the greatest improvement in system utility is selected. In the Local Search Stage, potential swaps are analyzed and a pair offering the greatest improvement that exceeds a threshold is selected. The determining of activation fractions for all TPs is performed by utilizing an auxiliary function method.
    Type: Application
    Filed: August 28, 2015
    Publication date: February 4, 2016
    Inventors: Narayan Prasad, Vaibhav Singh, Sampath Rangarajan, Mustafa Arslan
  • Patent number: 9191962
    Abstract: Disclosed herein are techniques, methods, and apparatus pertaining to a multi-user scheduling in 4G and 3GPP LTE cellular uplinks.
    Type: Grant
    Filed: July 30, 2012
    Date of Patent: November 17, 2015
    Assignee: NEC Laboratories America, Inc.
    Inventors: Narayan Prasad, Honghai Zhang, Sampath Rangarajan
  • Publication number: 20150312903
    Abstract: In a wireless communications system including a first transmission point and a second transmission point, a wireless communications method implemented in the first transmission point supporting coordinated multi-point transmission and reception (CoMP) is disclosed. The wireless communications method comprises transmitting to the second transmission point one or more CoMP hypothesis sets, and transmitting to the second transmission point a benefit metric corresponding to each CoMP hypothesis set, wherein the benefit metric can be a negative value. Other methods, systems, and apparatuses also are disclosed.
    Type: Application
    Filed: March 18, 2015
    Publication date: October 29, 2015
    Inventors: Narayan Prasad, Mohammad Khojastepour, Mustafa Arslan, Karthikeyan Sundaresan, Sampath Rangarajan
  • Publication number: 20150312893
    Abstract: A wireless communications method implemented in a transmission point (TP) used in a wireless communications system is disclosed. The wireless communications method comprises receiving, from another TP, channel state information (CSI) for a user equipment (UE), and receiving, from said another TP, user identification for the user equipment, wherein the signaling of the CSI for the user equipment enables user identification for the user equipment. Other methods, systems, and apparatuses also are disclosed.
    Type: Application
    Filed: March 18, 2015
    Publication date: October 29, 2015
    Inventors: Narayan Prasad, Mohammad Khojastepour, Mustafa Arslan, Karthikeyan Sundaresan, Sampath Rangarajan
  • Publication number: 20150288434
    Abstract: A method implemented in a user equipment used in a wireless communications system is disclosed. The method comprises receiving from a base station an indication of a first modulation type for the user equipment, receiving from the base station a first data signal for the user equipment, receiving from the base station an indication of a minimum time-frequency unit that is assigned to another user equipment, receiving a second data signal for said another user equipment, where a second modulation type for said another user equipment is unknown to the user equipment, and cancelling and suppressing interference by using the minimum time-frequency unit. Other methods, systems, and apparatuses also are disclosed.
    Type: Application
    Filed: June 19, 2015
    Publication date: October 8, 2015
    Inventors: Narayan Prasad, Guosen Yue, Mohammad A. Khojastepour, Meilong Jiang, Sampath Rangarajan
  • Patent number: 9148818
    Abstract: A method implemented in a mobile communications network supporting coordinated multiple point transmission and reception (CoMP) is disclosed. The method includes transmitting, to a user equipment (UE), data in a physical downlink shared channel (PDSCH), and transmitting a reference signal to the UE, wherein a union of resource elements (REs) allocated for reference signals transmitted from a subset of a plurality of transmission points (TPs) in a CoMP set are excluded from resource mapping for transmitting the data to the UE. Other methods, systems, and apparatuses also are disclosed.
    Type: Grant
    Filed: January 25, 2013
    Date of Patent: September 29, 2015
    Assignee: NEC Laboratories America, Inc.
    Inventors: Guosen Yue, Narayan Prasad, Meilong Jiang, Sampath Rangarajan
  • Patent number: 9144076
    Abstract: A method for user pairing and resource allocation, includes performing a multiuser multi-input-multi-output (MU-MIMO) user pairing process to maximize an objective metric without common rank restriction; performing a rank balancing process to determine a uniform transmission user rank along all allocated resource blocks for each user; and with the uniform transmission user rank fixed for all the users, determining optimal user pairing and allocation for each of the resource blocks for each user.
    Type: Grant
    Filed: September 18, 2012
    Date of Patent: September 22, 2015
    Assignee: NEC Laboratories America, Inc.
    Inventors: Guosen Yue, Narayan Prasad, Sampath Rangarajan
  • Patent number: 9130620
    Abstract: There is provided a method for generating transmit precoders for a communication system having a plurality of transmitters and a plurality of receivers forming a plurality of transmitter-receiver pairs. Each of the transmitters and receivers has a respective plurality of antennas. The method includes initializing the transmit precoders. The method further includes updating a plurality of receiver filters and a plurality of slack variables using closed form expressions. The method also includes updating the transmit precoders responsive to an output of said prior updating step. The method additionally includes iteratively repeating the updating steps until convergence is reached to obtain a final set of transmit precoders. The transmit precoders are updated to perform precoding for multiple stream data transmission for each of the plurality of transmitter-receiver pairs on each of a plurality of slots under a per-antenna power constraint imposed on each of the plurality of antennas.
    Type: Grant
    Filed: November 19, 2013
    Date of Patent: September 8, 2015
    Assignee: NEC Laboratories America, Inc.
    Inventor: Narayan Prasad
  • Patent number: 9124319
    Abstract: A method implemented in a user equipment used in a multi-user multiple input multiple output (MU-MIMO) wireless communications system is disclosed. The method includes receiving from a base station an indication of a first modulation type for the user equipment, receiving a first data signal for the user equipment, receiving a second data signal for a co-scheduled user equipment, where a second modulation type for the co-scheduled user equipment is unknown to the user equipment, and deciding the second modulation type. Other methods, systems, and apparatuses also are disclosed.
    Type: Grant
    Filed: April 22, 2014
    Date of Patent: September 1, 2015
    Assignee: NEC Laboratories America, Inc.
    Inventors: Narayan Prasad, Guosen Yue, Mohammad A. Khojastepour, Meilong Jiang, Sampath Rangarajan