Patents by Inventor Amitava Ghosh

Amitava Ghosh 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: 7477699
    Abstract: A radio communications device (102) that has multiple receive antennas processes received data communications signals to select between space time coding and spatial multiplexing as a selected transmission technique from a base device (104) that has multiple transmit antennas. A channel throughput (402-412, 450-454) for each transmission technique is estimated based on signal to interference and noise ratios (502-512, 550-554) of signals being transmitted through a MIMO channel (140) as measured by a receiver (708). The transmission technique with the higher estimated throughput is determined. If spatial multiplexing is determined to have the higher estimated throughput and the throughput of each layer of the spatially multiplexed signal is greater than a threshold, spatial multiplexing is selected. Otherwise, space time coding is selected.
    Type: Grant
    Filed: December 20, 2006
    Date of Patent: January 13, 2009
    Assignee: Motorola, Inc.
    Inventors: Fan Wang, Lawrence A. Downing, Amitava Ghosh, Chandrasekar Sankaran, Jun Tan
  • Publication number: 20080232492
    Abstract: An Orthogonal Frequency Division Multiplexing communication system, wherein a frequency bandwidth is divided into one or more Resource Blocks Groups (RBGs) each having one or more Resource Blocks, provides for feedback of channel quality information and precoding metrics for a same at least one RBG of the one or more RBGs. More particularly, a user equipment measures one or more channel quality parameters associated with at least one RBG of the one or more RBGs, determines channel quality information and a precoding metric for an RBG of the at least one RBG, and reports the channel quality information and a precoding metric determined for the RBG to a radio access network. In one embodiment of the invention, the RBG whose channel quality information and precoding metric are reported may be selected from the at least one RBG based on the measured channel quality parameters.
    Type: Application
    Filed: March 10, 2008
    Publication date: September 25, 2008
    Applicant: MOTOROLA, INC.
    Inventors: Weimin Xiao, Amitava Ghosh, Rapeepat Ratasuk
  • Patent number: 7428416
    Abstract: A cellular communication system includes first and second base stations and a user equipment. A Radio Network Controller controls a handover of the user equipment between the base stations by either forwarding data of the communication to both the first and second base stations or to only one of the first and second base stations dependent on a Quality of Service (QoS) characteristic of the communication of the user equipment. The QoS characteristic can specifically be an indication of a delay constraint for the communication service such as an indication of whether the service is a real-time service or a non-real time service.
    Type: Grant
    Filed: November 29, 2005
    Date of Patent: September 23, 2008
    Assignee: Motorola, Inc.
    Inventors: Nick W. Whinnett, Amitava Ghosh, Weimin Xiao
  • Publication number: 20080192847
    Abstract: A communication is provided that schedules both Distributed Virtual Resource Blocks (DVRB) and Localized Virtual Resource Blocks (LVRB) in a same frequency channel, thereby obtaining the benefits of frequency selective scheduling while minimizing the uplink feedback overhead. In one embodiment of the invention, the communication system assigns one or more downlink Physical Resource Blocks (PRBs) of multiple downlink Physical Resource Blocks (PRBs) to each user equipment (UE) given an LVRB to produce at least one reserved PRB and multiple non-reserved PRBs and assigns a part of each PRB of the multiple non-reserved PRBs to a UE given a DVRB. In another embodiment of the invention, the communication system assigns PRBs pre-reserved for localized transmission to UEs scheduled for LVRBs and assigns parts of multiple PRBs pre-reserved for distributed transmission to each UE given a DVRB.
    Type: Application
    Filed: January 31, 2008
    Publication date: August 14, 2008
    Applicant: MOTOROLA, INC.
    Inventors: Brian K. Classon, Kevin L. Baum, Amitava Ghosh, Robert T. Love, Vijay Nangia, Rapeepat Ratasuk, Weimin Xiao
  • Publication number: 20080188260
    Abstract: A communication system optimizes cell edge performance and spectral efficiency by a first step of measuring, by the Node B, at least one system performance metric. A next step includes sending, by the Node B, an indicator for the at least one system performance metric measurement. A next step includes receiving the indicator for the at least one system performance metric measurement. A next step includes determining an adaptive power control parameter based on the at least one system performance metric measured by the Node B and system performance metrics measured by at the least one other neighboring Node B. A next step includes using the adaptive power control parameter to update an uplink transmit power level for at least one user equipment served by the Node B.
    Type: Application
    Filed: January 29, 2008
    Publication date: August 7, 2008
    Applicant: MOTOROLA, INC.
    Inventors: Wemin Xiao, Amitava Ghosh, Robert T. Love, Ravikiran Nory, Rapeepat Ratasuk, Yakun Sun
  • Publication number: 20080165873
    Abstract: A user equipment (UE) operating in an Orthogonal Frequency Division Multiplexing communication system transmits Layer 1 and Layer 2 user data non-associated and user data associated control signaling on an uplink by puncturing user data information with the user data non-associated and user data associated control signaling to produce a data stream wherein the control signaling and user data information are multiplexed. The UE then conveys the punctured data stream to a radio access network via an air interface. The communication system further provides for a selection of a coding and modulation for the control signaling based on a modulation and coding scheme of the user data and a transmission scheme that is applied for transmission of the user data information over the air-interface.
    Type: Application
    Filed: September 25, 2007
    Publication date: July 10, 2008
    Applicant: MOTOROLA, INC.
    Inventors: Amitava Ghosh, Rapeepat Ratasuk, Weimin Xiao
  • Publication number: 20080165733
    Abstract: A method and apparatus for assigning a communication resource is disclosed. The method includes allocating a channel by a base station or Node B 102. The base station or Node B detects an energy level transmitted on the channel wherein the energy level may contention-free for a plurality of user equipment 104. The base station or Node B assigns time frequency resources for at least one of the plurality of user equipment wherein the time frequency resources are proportional to the detected energy level.
    Type: Application
    Filed: November 1, 2007
    Publication date: July 10, 2008
    Applicant: Motorola, Inc.
    Inventors: Weimin Xiao, Amitava Ghosh, Rapeepat Ratasuk
  • Publication number: 20080151804
    Abstract: A radio communications device (102) that has multiple receive antennas processes received data communications signals to select between space time coding and spatial multiplexing as a selected transmission technique from a base device (104) that has multiple transmit antennas. A channel throughput (402-412, 450-454) for each transmission technique is estimated based on signal to interference and noise ratios (502-512, 550-554) of signals being transmitted through a MIMO channel (140) as measured by a receiver (708). The transmission technique with the higher estimated throughput is determined. If spatial multiplexing is determined to have the higher estimated throughput and the throughput of each layer of the spatially multiplexed signal is greater than a threshold, spatial multiplexing is selected. Otherwise, space time coding is selected.
    Type: Application
    Filed: December 20, 2006
    Publication date: June 26, 2008
    Applicant: MOTOROLA, INC.
    Inventors: Fan Wang, Lawrence A. Downing, Amitava Ghosh, Chandrasekar Sankaran, Jun Tan
  • Publication number: 20080081671
    Abstract: A subscriber unit (104) with multiple receive antennas (160, 162) and a single transmit antenna (160) derives beamforming weights to be used at a base station (102) with multiple transmitting antennas (602, 604, 606, and 608). The downlink beamforming weights are derived at the subscriber unit (104) from a prior downlink transmission from the base station (102) to the subscriber device (104) and an uplink sounding signal is used to carry derived downlink beam forming weights to the base station (102). Downlink antenna specific pilots (without weight) are used at the subscriber device (104) to determine the beamforming weights. Decimated sounding signals, where the number of sounding subcarriers is al least the same as the number of antennas at the base station (102), allow multiple users to sound at the same time.
    Type: Application
    Filed: October 3, 2006
    Publication date: April 3, 2008
    Applicant: MOTOROLA, INC.
    Inventors: Fan Wang, Stanley J. Benes, Amitava Ghosh, Jun Tan
  • Publication number: 20080049749
    Abstract: Embodiments of the present invention provide a manner in which feedback from remote units (120-122) involved in a broadcast/multicast service session can be obtained using shared wireless resources and/or shared signaling sequences. Having feedback information from at least some of the remote units involved in the session enables the network equipment (101) to dynamically manage the session and potentially improve the performance of the session. Moreover, utilizing shared wireless resources and/or shared signaling sequences may reduce the overhead cost of obtaining the feedback as compared to utilizing dedicated resources.
    Type: Application
    Filed: August 22, 2006
    Publication date: February 28, 2008
    Applicant: MOTOROLA, INC.
    Inventors: Weimin Xiao, Amitava Ghosh, Rapeepat Ratasuk
  • Patent number: 7321570
    Abstract: A communication system is provided that dynamically allocates power to a Multimedia Broadcast/Multicast Service (an MBMS service). In response to determining to establish a Point-to-Multipoint (PTM) communication channel to multiple user equipment (UEs), the communication service assigns the PTM communication channel to the MBMS service, determines a power requirement associated with each user equipment (UE) of the multiple UEs based on a handover quality measurement associated with the UE to produce multiple power requirements, and allocates a power level to the PTM communication channel based on the multiple power requirements. The communication system further dynamically adjusts the allocated power based on a handover quality measurement associated with a UE of the multiple UEs that is received during provision of the MBMS service.
    Type: Grant
    Filed: February 3, 2004
    Date of Patent: January 22, 2008
    Assignee: Motorola, Inc.
    Inventors: Rapeepat Ratasuk, Jean-Aicard Fabien, Amitava Ghosh, Weimin Xiao
  • Publication number: 20080013499
    Abstract: A communications network (200) for enhanced uplink of High-Speed Uplink Packet Access (HSUPA) in 3G wireless communications includes a mobile transceiver unit (605). The mobile transceiver unit is operable to use a channel prediction to estimate a power margin of one or more dedicated channels, predict a power margin for an acknowledgement transmission based on transmission parameters, reserve a power margin for a channel quality indicator (CQI) transmission, and determine an Enhanced Transport Format Combination (E-TFC) for an uplink data packet transmission based on an available power margin. The communications network also includes a communications network node (610) operable to transmit a power control signal to the mobile transceiver unit.
    Type: Application
    Filed: July 13, 2006
    Publication date: January 17, 2008
    Inventors: Rapeepat Ratasuk, Amitava Ghosh, Weimin Xiao
  • Publication number: 20070293260
    Abstract: A communication system optimizes cell edge performance and spectral efficiency by determining an adaptive power control parameter based on system performance metrics measured by a serving Node B and further measured by, and reported to the serving Node B by, neighboring Node B's. The adaptive power control parameter is then used to determine an uplink transmit power of a user equipment (UE) served by the serving Node B. The uplink transmit power may be determined by the Node B and then conveyed to the UE, or the Node B may broadcast the adaptive power control parameter to the UE and the UE may self-determine the uplink transmit power. In addition, as a frequency reuse factor of one has been proposed for such communication systems, interference levels may be even further improved by employment of an intra-site interference cancellation scheme in the sectors serviced by the Node B.
    Type: Application
    Filed: February 19, 2007
    Publication date: December 20, 2007
    Applicant: MOTOROLA, INC.
    Inventors: Weimin Xiao, Amitava Ghosh, Rapeepat Ratsuk
  • Publication number: 20070258540
    Abstract: A communication system provides downlink acknowledgments corresponding to uplink transmission using hybrid automatic repeat request to multiple users in an Orthogonal Frequency Division Multiplexing communication system, wherein a frequency bandwidth comprises multiple frequency sub-carriers, by spreading each acknowledgment of multiple acknowledgments with a selected spreading sequence of multiple spreading sequences to produce multiple spread acknowledgments, wherein each acknowledgment is intended for a different user of the multiple users, and distributing the multiple spread acknowledgments across the multiple frequency sub-carriers.
    Type: Application
    Filed: March 28, 2007
    Publication date: November 8, 2007
    Applicant: MOTOROLA, INC.
    Inventors: Rapeepat Ratasuk, Amitava Ghosh, Weimin Xiao
  • Patent number: 7289567
    Abstract: An apparatus and method for transmitting and receiving data, wherein retransmissions of information can be a different size from the initial transmission. The invention utilizes a partial Chase encoder 306 to truncate or expand data depending on the availability of channel resources for retransmission. A partial Chase combiner 314 processes the received demodulated data based solely on the number of codes and modulation received (i.e., predetermined, with no additional signaling required). If the received retransmission is smaller than the first transmission, only a portion of the soft bits are combined. If the retransmission is larger than the first transmission, some values of the stored first transmission are combined with more than one received soft bit in the retransmission.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: October 30, 2007
    Assignee: Motorola, Inc.
    Inventors: Brian K. Classon, Amitava Ghosh
  • Patent number: 7260770
    Abstract: A method of block puncturing for turbo code based incremental redundancy includes a first step (1200) of coding an input data stream into systematic bits and parity bits. A next step (1202) includes loading the systematic bits and parity bits into respective systematic and parity block interleavers in a column-wise manner. A next step (1204) includes selecting a predefined redundancy. A next step (1206) includes outputting bits from the block interleavers in a row-wise manner in accordance with the selected predefined redundancy.
    Type: Grant
    Filed: October 22, 2001
    Date of Patent: August 21, 2007
    Assignee: Motorola, Inc.
    Inventors: Kenneth A. Stewart, Amitava Ghosh, Michael E. Buckley, Raja S. Bachu, Rapeepat Ratasuk
  • Publication number: 20070178930
    Abstract: To address the need for a resource allocation scheme that results in a better tradeoff between the cell-edge performance and the overall spectral efficiency, a communication system is provided that allocates uplink transmit power to user equipment (UEs) based on a fractional power control scheme. In another embodiment, since the cell-edge users are also likely to be power limited, the communication system may implement a minimized uplink transmission bandwidth resource allocation scheme that may work with the fractional power control scheme to achieve a level of performance desired for uplink transmissions in 3GPP (Third Generation Partnership Project) and 3GPP2 Evolution communication systems.
    Type: Application
    Filed: January 9, 2007
    Publication date: August 2, 2007
    Applicant: MOTOROLA, INC.
    Inventors: Weimin Xiao, Amitava Ghosh, Robert T. Love, Rapeepat Ratasuk, Yakun Sun
  • Publication number: 20070165567
    Abstract: A system and method for initializing a system communication without previous reservations for random access channel (RACH) access includes a first step of defining at least one spread sequence derived from at least one constant amplitude zero autocorrelation sequence. A next step includes combining the spread sequence with a Walsh code to form an extended spread sequence. A next step includes using the extended spread sequence in a preamble for a RACH. A next step includes sending the preamble to a BTS for acquisition. A next step includes monitoring for a positive acquisition indicator from the BTS. A next step includes scheduling the sending of a RACH message. A next step includes sending the RACH message.
    Type: Application
    Filed: January 10, 2007
    Publication date: July 19, 2007
    Applicant: MOTOROLA, INC.
    Inventors: Jun Tan, Amitava Ghosh, Rapeepat Ratasuk, Fan Wang, Weimin Xiao
  • Publication number: 20070165731
    Abstract: Various embodiments are described which can serve to mitigate interference between the control channel signaling of adjacent sectors/cells. Potentially, these techniques may have the benefit of reducing the system resource drain caused by control channels, particularly control channels in high frequency-reuse, OFDMA systems. A transmitting device (101) transmits primary control channel information to a plurality of user devices (102). The primary control channel information includes an indication that a first OFDMA resource region (e.g., 320 or 330) is assigned to at least one user device of the plurality of user devices. The transmitting device correspondingly transmits secondary control channel information to the at least one user device using the first OFDMA resource region.
    Type: Application
    Filed: January 16, 2007
    Publication date: July 19, 2007
    Applicant: MOTOROLA, INC.
    Inventors: Weimin Xiao, Amitava Ghosh, Rapeepat Ratasuk, Brian K. Classon, Kevin L. Baum, Robert T. Love
  • Publication number: 20070165730
    Abstract: A transmitter comprises functionality (101, 103) for generating a block of input modulation symbols for example from received data bits. An M-point discrete Fourier transform (105) is applied to the block of input modulation symbols resulting in a frequency domain symbol block. This block is fed to an N-point inverse discrete Fourier transform (105) (N>M) thereby generating a time domain transmit signal. In addition, the transmitter (200) comprises an inter-symbol processor (201) which determines inter-symbol values corresponding to inter-symbol times of the time domain transmit signal and an attenuation processor (203) which attenuates at least one of the input modulation symbols in response to the inter-symbol values. By attenuating selected input modulation symbol(s) a significantly reduced amplitude variation and specifically peak-to-average amplitude variation can be achieved.
    Type: Application
    Filed: October 6, 2006
    Publication date: July 19, 2007
    Applicant: MOTOROLA, INC.
    Inventors: Nick W. Whinnett, Amitava Ghosh, Jun Tan