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).

  • Publication number: 20040116143
    Abstract: A communication system supports H-ARQ, AMC, active set handoff, and scheduling functions in a distributed fashion by allowing a mobile station (MS) to signal control information corresponding to an enhanced reverse link transmission to Active Set base transceiver stations (BTSs) and by allowing the BTSs to perform control functions that were supported by an RNC in the prior art. The communication system allows time and SIR-based H-ARQ flush functions at the BTSs during soft handoff (SHO), provides an efficient control channel structure to support scheduling, H-ARQ, AMC functions for an enhanced reverse link, or uplink, channel in order to maximize throughput, and enables an MS in a SHO region to choose a scheduling assignment corresponding to a best TFRI out of multiple assignments it receives from multiple active set BTS. As a result, the enhanced uplink channel can be scheduled during SHO without any explicit communication between the BTSs.
    Type: Application
    Filed: October 28, 2003
    Publication date: June 17, 2004
    Inventors: Robert T. Love, Kenneth A. Stewart, Amitava Ghosh
  • Publication number: 20040023659
    Abstract: Various gain factors for pilot information are used to determine a corresponding plurality of likely channel performance values for a plurality of data channels (and/or services). The resultant information is used to select a specific gain factor to apply when transmitting the pilot information. In one embodiment, the gain factor that correlates to the highest signal to interference plus noise ratio is used.
    Type: Application
    Filed: July 31, 2002
    Publication date: February 5, 2004
    Applicant: Motorola, Inc.
    Inventors: Weimin Xiao, Rapeepat Ratasuk, Amitava Ghosh
  • Patent number: 6678523
    Abstract: A method of combining soft-handoff with a hybrid ARQ scheme to maximize throughput and gain in a communications system. After receiving a frame from the MS (110), the BTSs (104 and 106) will process the frame and communicate to the MS over a forward control channel whether the frame contained any errors. If all BTSs communicate that the frame contains errors, the MS will retransmit the same frame to all BTSs with a flush bit set to instruct the BTSs 104 and 106 to combine the retransmitted frame with the original frame. If only some BTSs communicate that the frame contains errors, the MS will transmit the next frame to all BTSs that successfully decoded the frame with the flush bit set to instruct the BTSs to erase the previous frame from memory and not to combine the previous frame with the current frame. The MS will retransmit the frame to the BTSs that did not successfully decode the frame with the flush bit set to instruct the BTSs to combine the previous frame with the retransmitted frame.
    Type: Grant
    Filed: November 3, 2000
    Date of Patent: January 13, 2004
    Assignee: Motorola, Inc.
    Inventors: Amitava Ghosh, Louay Jalloul
  • Publication number: 20030161343
    Abstract: Method and system for selecting the most suitable logic channel for transmitting packet data in a third generation cellular communications system enables a radio network controller (102) to set bit rate, spread factor and frames required from information supplied by user equipment (104) and the node B's (110) comprising the system. Such information comprises queue size, reported by the user equipments, and noise rise measurements due to user equipment activity, reported by the node B's. The invention advantageously allows a logic channel to be chosen based on the prevailing system state conditions. Hence performance of the system is optimised.
    Type: Application
    Filed: December 16, 2002
    Publication date: August 28, 2003
    Inventor: Amitava Ghosh
  • Publication number: 20030159100
    Abstract: An improved turbo code based incremental redundancy includes a first step of puncturing a data stream for a first transmission to provide a set of first unpunctured trellis sections. A next step includes puncturing a data stream for a second transmission to provide a set of second unpunctured trellis sections. A next step includes incremental redundancy combining the first and second transmissions of the trellises to provide non-adjacent first and second unpunctured trellis sections. The above arrangement results in a uniform distribution of punctured and unpunctured bits to provide lower errors.
    Type: Application
    Filed: February 11, 2002
    Publication date: August 21, 2003
    Inventors: Michael E. Buckley, Raja S. Bachu, Amitava Ghosh, Rapeepat Ratasuk, Kenneth A. Stewart, Mathieu Villion
  • Publication number: 20030079170
    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: Application
    Filed: October 22, 2001
    Publication date: April 24, 2003
    Inventors: Kenneth A. Stewart, Amitava Ghosh, Michael E. Buckley, Raja S. Bachu, Rapeepat Ratasuk
  • Publication number: 20030035469
    Abstract: The present invention provides linear MMSE equalization with parallel interference cancellation for symbol determination in a forward link of a CDMA communication system which has a plurality of code channels in use. Use of the linear MMSE equalization with parallel interference cancellation of the present invention provides significantly increased performance. The preferred method linearly filters a received signal to form a first filtered signal (410), despreads and demodulates the first filtered signal (415, 420) and provides a plurality of symbol estimates for all corresponding code channels (430). An estimated transmitted signal is generated from the plurality of symbol estimates (435), and with a channel estimate (405), an estimated received signal is generated (440).
    Type: Application
    Filed: August 20, 2001
    Publication date: February 20, 2003
    Inventors: Colin D. Frank, Eugene Visotsky, Prashant Choudhary, Amitava Ghosh
  • Publication number: 20020159384
    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: Application
    Filed: March 28, 2002
    Publication date: October 31, 2002
    Inventors: Brian K. Classon, Amitava Ghosh
  • Patent number: 6430214
    Abstract: An architecture for simplified automatic gain control circuit (100, 200, 300) that is useable with M-ary QAM systems to improve overall link performance. The implementations particularly relating to modulating an M-ary QAM constellation according to a set of estimates derived from the pilot channel(s) and/or the traffic channels, modulating the M-ary QAM constellation according to the values of the pilot and traffic channel gains that are being sent to a mobile wireless device on a control channel, and using a power control bit at the mobile wireless device to modulate the M-ary QAM constellation, all resulting in improved receiver performance.
    Type: Grant
    Filed: May 22, 2000
    Date of Patent: August 6, 2002
    Assignee: Motorola, Inc.
    Inventors: Louay Jalloul, Amitava Ghosh
  • Publication number: 20020075842
    Abstract: A method in a communication system (100) includes transmitting from a source user (101) a first data packet (111) over a first time frame (121) having a finite time period (131), transmitting from source user (101) a second data packet (112) over a second time frame (122) immediately subsequent to first time frame (121), detecting an acknowledgment of acceptable reception of data packet associated with either first or said second data packets (111 and 112), repeating transmission of first and second data packets (111 and 112) in a sequence of first and second time frames (121 and 122) in a time frame sequence (190) until the detection.
    Type: Application
    Filed: March 19, 2001
    Publication date: June 20, 2002
    Inventors: Amitava Ghosh, Brian Classon, Mark Cudak, Louay A. Jalloul
  • Patent number: 6366601
    Abstract: A communication system (100) provides selecting a first modulation-coding scheme (111) based on a quality indicator of a communication between a source user and a first destination user, determining a first possible number of data bits (201) that can be modulated and encoded according to selected modulation-coding scheme (111) and spread according to one spreading code of a plurality of spreading codes (108-1 through 108-k) which results in fitting in a predetermined time frame, determining a first number of data bits (102) to be transmitted from the source user to the first destination user, determining a first load level based on comparing first number of data bits (102) and first possible number of data bits (201), and, if the first load level is unequal to a whole number, rounding to a next first whole number, selecting a first number of plurality of spreading codes (108-1 through 108-k) based on the first whole number of load level for spread coding of first number of data bits (102) after being modulate
    Type: Grant
    Filed: November 17, 1999
    Date of Patent: April 2, 2002
    Assignee: Motorola, Inc.
    Inventors: Amitava Ghosh, Brian K. Classon, Mark C. Cudak, Louay Jalloul
  • Patent number: 6308294
    Abstract: A generic structure of Hybrid ARQ using Turbo Codes is provided which requires the function of a) channel coding, b) redundancy selection, c) buffering and max-ratio diversity combining, d) channel decoding, e) error detection and f) sending back an acknowledgement to the transmitter. The functions (a) and (b) are performed at the transmitter while functions (c) to (f) are performed at the receiver. The initial code rate can be explicitly communicated to the receiver or blindly detected.
    Type: Grant
    Filed: June 26, 2000
    Date of Patent: October 23, 2001
    Assignee: Motorola, Inc.
    Inventors: Amitava Ghosh, Brian K. Classon, Mark C. Cudak, Louay Jalloul
  • Patent number: 6275488
    Abstract: A method in a communication system (100) includes transmitting from a source user (101) a first data packet (111) over a first time frame (121) having a finite time period (131), transmitting from source user (101) a second data packet (112) over a second time frame (122) immediately subsequent to first time frame (121), detecting an acknowledgment of acceptable reception of data packet associated with either first or said second data packets (111 and 112), repeating transmission of first and second data packets (111 and 112) in a sequence of first and second time frames (121 and 122) in a time frame sequence (190) until the detection.
    Type: Grant
    Filed: November 17, 1999
    Date of Patent: August 14, 2001
    Assignee: Motorola, Inc.
    Inventors: Mark C. Cudak, Brian K. Classon, Louay Jalloul, Amitava Ghosh
  • Patent number: 6253063
    Abstract: A mobile station (110) selects an initial data rate for communication between base station (107) and mobile station (110). Mobile station (110) communicates the selected initial data rate to base station (107) through uplink (112). Base station (107) determines a difference level of interference condition experienced by mobile station (107) between a time when the initial data rate was selected by mobile station (110) and a time when base station (107) prepares to communicate to mobile station (110). Base station (107) selects a final data rate for transmission from base station (107) to mobile station (110) based on the determined difference level of interference condition. As such, the initial data rate may be modified to the final data rate while maximizing the down link capacity.
    Type: Grant
    Filed: January 25, 2000
    Date of Patent: June 26, 2001
    Assignee: Motorola, Inc.
    Inventors: Mark C. Cudak, Brian K. Classon, Louay A. Jalloul, Amitava Ghosh, Robert T. Love
  • Patent number: 6233231
    Abstract: Remote units (113) having large amounts of data to transmit will be dynamically assigned Orthogonal Variable Spreading Factor (OVSF) codes corresponding to higher data rates and remote units (113) with lower amounts of data to be transmitted will be assigned OVSF codes corresponding to lower data rates. Additionally, in an alternate embodiment of the present invention, once system interference becomes greater than a predetermined threshold, the data rate between the base station (100) and remote units (113) in communication with the base station (100) is reduced. The reduction of the data rate between the base station (100) and remote units (113) occurs by changing the current OVSF codes utilized by both the remote units (113) and the base station (100).
    Type: Grant
    Filed: December 3, 1998
    Date of Patent: May 15, 2001
    Assignee: Motorola, Inc.
    Inventors: Kenneth A. Felix, Mark C. Cudak, Amitava Ghosh
  • Patent number: 6091757
    Abstract: Remote units (113) having large amounts of data to transmit will be dynamically assigned Orthogonal Variable Spreading Factor (OVSF) codes corresponding to higher data rates and remote units (113) with lower amounts of data to be transmitted will be assigned OVSF codes corresponding to lower data rates. The reduction of the data rate between the base station (100) and remote units (113) occurs by changing the current OVSF codes utilized by both the remote units (113) and the base station (100). In order to eliminate collisions among remote units transmitting data, a remote units transmission is advanced and retarded in time based on an amount of offset from a frame boundary.
    Type: Grant
    Filed: January 13, 1999
    Date of Patent: July 18, 2000
    Assignee: Motorola, Inc.
    Inventors: Mark C. Cudak, Amitava Ghosh
  • Patent number: 6018667
    Abstract: Base stations (101, 102) utilize a spreading code that is dependent upon whether the particular base station (101) is operating in a synchronized, or an unsynchronized mode. Unsynchronized base stations (102) within the communication system (100) utilize a long code unique to the particular base station (102), and base stations (101) operating in a synchronized mode utilize a time shifted version of the same long code. To reduce the search time for remote units (113) within the communication system (100), a group identification code (GIC) (305) is broadcast during a time period that the long code is masked. The GIC (305) indicates a (spreading code) long code group to which the long code of each base station belongs. Additionally, each base station (101, 102) within the communication system (100) determines its synchronization status and utilizes a particular GIC (305) and long code based on the base station's synchronization status.
    Type: Grant
    Filed: January 20, 1998
    Date of Patent: January 25, 2000
    Assignee: Motorola, Inc.
    Inventors: Amitava Ghosh, Gerald Paul Labedz, Kenneth Allen Haas
  • Patent number: 6009091
    Abstract: A Dedicated Physical Location Channel (DPLCH) is utilized by a mobile station (913) to support subscriber location functions. The DPLCH is spread by an Orthogonal Variable Spreading Factor (OVSF) code C.sub.L (502) of length 256 which is distinct from those OVSF codes assigned to other channels utilized by the mobile station (913). When a power-up function (PUF) is received by the mobile station (913), the DPLCH sub-channel amplitude is then modified relative to the other channels being utilized by the mobile station (913) using gain module G.sub.L (503) prior to combination (504) with the other channels.
    Type: Grant
    Filed: March 13, 1998
    Date of Patent: December 28, 1999
    Assignee: Motorola, Inc.
    Inventors: Kenneth A. Stewart, Amitava Ghosh
  • Patent number: 5991285
    Abstract: In a code division multiple access communication system providing a plurality of communication type services between a first unit (100) and a second communicating unit (200) by time-multiplexing a plurality of data channel signals (101, 102, 103) associated with the plurality of communication type services to produce a time-multiplexed data channel signal (106) which are combined to produce a combined signal (136). Combined signal (136) is transmitted from first unit (100) to be received by second unit (200). After producing a code-demultiplexed time-multiplexed data channel signal (218), and a plurality of signal-to-interference ratios estimated based on a plurality of time-multiplexed portions of signal (218), a plurality of power control thresholds corresponding to the plurality of communication type services are compared to the plurality of signal-to-interference ratios. As a result, producing a plurality of power control data bits corresponding to the plurality of communication type services based.
    Type: Grant
    Filed: August 10, 1998
    Date of Patent: November 23, 1999
    Assignee: Motorola, Inc.
    Inventor: Amitava Ghosh
  • Patent number: 5945948
    Abstract: A method for determining a subscriber unit location in a communication system is provided. The method includes the steps of receiving a signal from the subscriber unit at a first base station, determining a first receive time of the signal based on a sequence of spreading symbols at the first base station, determining a first angle of arrival of the signal at the first base station, and determining the location of the subscriber unit from the first receive time, the first angle of arrival, and further predetermined information about the first base station. The signal is formed via modulation by the sequence of spreading symbols.
    Type: Grant
    Filed: September 3, 1996
    Date of Patent: August 31, 1999
    Assignee: Motorola, inc.
    Inventors: Kevin A. Buford, John D. Reed, Walter J. Rozanski, Jr., Amitava Ghosh