Patents Assigned to Ericsson, Inc.
  • Patent number: 7123936
    Abstract: A cellular telephone includes an internally integrated digital entertainment module. The telephone includes a transceiver unit and a headset which is connected to the transceiver unit by wired or wireless link. The entertainment module includes an interchangeable ROM and/or expansion RAM for storing music or other audio signals for playback through the telephone's headset. Music or other audio signals in digitized form is stored in the interchangeable ROM or is loaded into the expansion RAM from a CD player, computer, or other source of digitized audio signals. Under control of the cellular telephone's microprocessor, the digitally stored audio signal is played back through the telephone's headset. The entertainment module may be located in the transceiver unit, a removable battery pack, or in a separate adapter.
    Type: Grant
    Filed: February 18, 1998
    Date of Patent: October 17, 2006
    Assignee: Ericsson Inc.
    Inventors: Nils R. C. Rydbeck, John Fussell
  • Patent number: 7120149
    Abstract: Methods and a related data routing system for handling received data packets that are out of sequence and were previously declared lost. Following receipt of a data packet, it is determined if the sequence number of the received data packet is out of order in comparison to previously received data packets. If the sequence number is out of order, the distance between the out of order sequence number and the sequence number of the last data packet that was received in sequence is calculated. The distance is used to discard or keep the received data packet based on a predetermined amount of threshold level of distance, the threshold level of distance being a function of the finite amount of memory space of the data transmission device.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: October 10, 2006
    Assignee: Ericsson Inc.
    Inventor: Bahman Salamat
  • Patent number: 7114178
    Abstract: An access control system includes an access control device, a wireless communication device, and a central controller. The central controller issues authorization codes to the wireless communication device. The wireless communication device is used by an authorized party to enable or activate a protected function secured by an access control device. To enable or activate the protected function, the authorized party uses the wireless communication device to transmit an access request to the access control device, which responds by transmitting an authentication challenge to the wireless communication device. The wireless communication device must transmit a valid authentication response based on the authentication challenge and a valid authorization code stored in its memory. If a valid authentication response is received, the access control device enables or activates the protected function.
    Type: Grant
    Filed: May 22, 2001
    Date of Patent: September 26, 2006
    Assignee: Ericsson Inc.
    Inventors: Paul W. Dent, Janez Skubic
  • Patent number: 7113745
    Abstract: A method of wirelessly communicating between units comprises using at least two repeaters between a transmit unit and a receive unit. The repeaters enable a diversity scheme to be emulated.
    Type: Grant
    Filed: February 21, 2001
    Date of Patent: September 26, 2006
    Assignee: Ericsson Inc.
    Inventor: Ali S. Khayrallah
  • Patent number: 7113593
    Abstract: A method and apparatus for performing cryptographic computations employing recursive algorithms to accelerate multiplication and squaring operations. Products and squares of long integer values are recursively reduced to a combination of products and squares reduced-length integer values in a host processor. The reduced-length integer values are passed to a co-processor. The values may be randomly ordered to prevent disclosure of secret data.
    Type: Grant
    Filed: March 6, 2001
    Date of Patent: September 26, 2006
    Assignee: Ericsson Inc.
    Inventors: Paul W. Dent, Ben Smeets, William J. Croughwell, III
  • Patent number: 7099410
    Abstract: The present invention involves demodulation of radio signals modulated with M-ary modulation in the presence of intersymbol interference distortion. The invention presents a method for reducing the number of multiplications needed to implement a maximum-likelihood-sequence-estimation (MLSE) equalizer for signals modulated with M-ary modulation. In exemplary embodiments of the present invention, the number of multiplications is reduced by pre-computing certain values needed for the determination of the branch metric and storing these pre-computed values in a product table. When a branch metric computation is to be made, whether it is an Euclidean branch metric computation or an Ungerboeck branch metric computation, certain multiplication operations are replaced by simple table look-up operations. As a result, the power efficiency and speed of the system are increased. Any receiver that demodulates signals that are modulated with M-ary modulation can be implemented using the present invention.
    Type: Grant
    Filed: January 26, 1999
    Date of Patent: August 29, 2006
    Assignee: Ericsson Inc.
    Inventors: Sandeep Chennakeshu, Kambiz Zangi, Gregory E. Bottomley
  • Patent number: 7088978
    Abstract: A communication receiver improves its channel estimation performance, its equalization performance, or both, by modeling the non-Gaussian characteristics of a dominant source of interference in a received signal. That is, rather than using Gaussian-based modeling, the receiver generates signal disturbance estimates using a probabilistic model representative of the non-Gaussian interference in a received signal, such as adjacent channel or co-channel signal interference in mobile station operating within a wireless communication network. The receiver may use such non-Gaussian interference modeling responsive to detecting such interference in the received signal and may match its disturbance model to the detected interference. Further, where signal disturbance is predominantly Gaussian in nature, the receiver may switch to a Gaussian disturbance model.
    Type: Grant
    Filed: February 7, 2003
    Date of Patent: August 8, 2006
    Assignee: Ericsson Inc.
    Inventors: Dennis Hui, Rajaram Ramesh
  • Patent number: 7088739
    Abstract: The present invention provides a method and apparatus for creating a packet using a digital signal processor. Call set-up information is received. Thereafter, call data is received and a data portion of the packet is created using the call data. One or more headers are created using the call data and the call set-up information. The packet is then created by attaching the one or more headers to the data portion of the packet. In addition, the one or more headers may include a real time transport protocol header, a user datagram protocol header, an Internet protocol header, and a media access control header.
    Type: Grant
    Filed: November 9, 2001
    Date of Patent: August 8, 2006
    Assignee: Ericsson Inc.
    Inventors: Alan DeMars, William Paul Harding-Jones
  • Patent number: 7085332
    Abstract: Method and apparatus for two-user join demodulation in a system having transmit diversity. A receiver includes at least a detector unit and a channel estimation unit, and exploits transmit diversity employed by at least one of two users or transmitters on a channel. Symbol detection and channel estimation are performed in block or batch fashion, or recursively on a symbol-by-symbol basis. Joint detection makes use of transmit diversity by at least one of the transmitting users. Channel estimates can be updated using channel tracking. If the signals from the first user and the second user are asynchronous, detection can be accomplished in part through reference to a pulse-shape component. The receiver may be incorporated into a mobile communication terminal.
    Type: Grant
    Filed: December 14, 2001
    Date of Patent: August 1, 2006
    Assignee: Ericsson, Inc.
    Inventor: Karl James Molnar
  • Patent number: 7079515
    Abstract: A time division multiple access (TDMA) radio communication system (100) accommodates signal decoding by a mobile station (130) with and without a second synchronization word (214). The radio communication system includes at least one base station (102, 104) to transmit radio signals during a succession of time slots (202, 204, 206) including a current time slot (202) and a subsequent time slot (204). The radio signals include an indication of whether transmission of the subsequent time slot is guaranteed. The system further includes at least one mobile station to receive the radio signals in accordance with the indication.
    Type: Grant
    Filed: May 13, 1999
    Date of Patent: July 18, 2006
    Assignee: Ericsson, Inc.
    Inventors: Paul W. Dent, Krister Raith
  • Patent number: 7068976
    Abstract: A base station tunes a transceiver to listen to accesses made by mobile terminals on the base station's own control channel. Once the functionality of the transceiver is verified by correlating the known accesses to the received accesses, the base station then tunes the transceiver to control channels of nearby cells to receive accesses directed to those nearby cells. From these accesses, the MSC can determine carrier-to-interference ratios between the cells.
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: June 27, 2006
    Assignee: Ericsson Inc.
    Inventors: Johnny Shepherd, Jeff Seifert
  • Patent number: 7069034
    Abstract: A communication system includes a mobile terminal and a base station. The mobile terminal estimates signal quality of a forward link during a first power control group period and determines a power control bit based on the estimated signal quality. The mobile terminal further transmits the power control bit on a reverse link during the first power control group period. The base station receives the power control bit on the reverse link and modifies forward link power based on the power control bit at commencement of a second power control group period.
    Type: Grant
    Filed: November 22, 2000
    Date of Patent: June 27, 2006
    Assignee: Ericsson Inc.
    Inventor: Essam Sourour
  • Patent number: 7061999
    Abstract: A received information signal is decoded to obtain the received information and to produce at least one feature of the received information signal. The received information signal is preliminary classified as containing a normal burst or a truncated burst based upon the at least one feature, to obtain a preliminary classification. Cyclic redundancy checking of the received information that is decoded is performed. The received information signal is then further classified as containing a normal burst or a truncated burst based upon the preliminary classification and whether the cyclic redundancy checking is valid, to obtain a further classification. The received information signal may be still further classified as containing a normal burst or a truncated burst based upon the further classification and at least one transition rule for normal bursts and truncated bursts between the received information signal and a previously received information signal.
    Type: Grant
    Filed: February 13, 2002
    Date of Patent: June 13, 2006
    Assignee: Ericsson Inc.
    Inventor: Dayong Chen
  • Patent number: 7061884
    Abstract: A first frame of carrier data can be communicated between a first carrier interface of a first radio base station node and a mobile switching center over a first carrier bus. In addition, a first frame of bus data can be communicated having a first number of dedicated control timeslots at a first bus interface of the first radio base station node over a first radio base station bus. Furthermore, a second frame of carrier data can be communicated between a second carrier interface of a second radio base station node and the mobile switching center over a second carrier bus. Finally, a second frame of bus data having a second number of dedicated control timeslots, different from the first number of dedicated control timeslots, can be communicated at a second bus interface of the second radio base station node over a second radio base station bus.
    Type: Grant
    Filed: October 29, 2001
    Date of Patent: June 13, 2006
    Assignee: Ericsson Inc.
    Inventors: Johnny Shepherd, Joseph Repice, John Wilcox
  • Patent number: 7054283
    Abstract: A method and apparatus for transmitting a location service message between a location server and a mobile station or LMU in a GPRS wireless communications system. The location server generates a location service message and transmits the location service message to a base station subsystem; the base station subsystem forwards the location service message to a serving GPRS support node; the serving GPRS support node then forwards the location service message to a mobile station or LMU), passing transparently back through the base station subsystem. This approach to system routing of location messages allows existing circuit-switched wireless communications systems to support location services in a GPRS environment with a minimum of alterations to existing hardware and software protocols.
    Type: Grant
    Filed: June 22, 2001
    Date of Patent: May 30, 2006
    Assignee: Ericsson Inc.
    Inventors: Hans Carlsson, Lennart Rinnback
  • Patent number: 7050802
    Abstract: A receiver receives communication signals on an assigned frequency channel while monitoring the signals received on other frequency channels. A communication processor processes the received communication signals from the current base station while a wideband digitizer processes received filtered signals on the other frequency channels, which correspond to the neighboring base stations. The wideband digitizer generates numerical samples representing the filtered signals in response to a control signal generated by a control processor. The control processor then determines characteristic signals of the frequency channels.
    Type: Grant
    Filed: April 23, 2003
    Date of Patent: May 23, 2006
    Assignee: Ericsson Inc.
    Inventor: Paul W. Dent
  • Patent number: 7050575
    Abstract: An echo canceler and method for a communications system include an echo-containing signal input for receiving a signal and an echo-causing signal source for developing an echo-causing signal. A first filter coupled to the echo-containing signal input and the echo-causing signal source filters the echo-containing signal over a predetermined time period using an existing filter coefficient set to provide a first echo-canceled output signal at a first filter output mode. A trial filter is coupled to the echo-containing signal input and the echo-causing signal source for processing the echo-containing signal over a predetermined time period using a trial filter coefficient set to provide a trial echo-cancel output signal at the trial filter output mode.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: May 23, 2006
    Assignee: Ericsson Inc.
    Inventor: Eric Douglas Romesburg
  • Patent number: 7046738
    Abstract: A method for generating a premodulation-filtered modulation waveform having a real part and an imaginary part for transmitting octal symbols uses a reduced lookup table. Successive octal symbols, each comprising three information bits, are input to a logic unit. The logic unit forms a first derived bit by combining the first and third information bits and a second derived bit by combining the second and third information bits. The first and second information bits, along with the first and second derived bits, are delayed in respective L-bit shift registers. The bit sequences in the L-bit shift registers are used to determine a corresponding filtered waveform segment for each bit sequence. The waveform segments corresponding to the delayed first information bits and the delayed first derived bits are combined to obtain a segment of said imaginary waveform part.
    Type: Grant
    Filed: February 8, 2000
    Date of Patent: May 16, 2006
    Assignee: Ericsson Inc.
    Inventor: Paul W. Dent
  • Patent number: 7046970
    Abstract: Phase modulation control techniques and supporting apparatus avoid phase discontinuity at the outset of RF signal generation. Such discontinuities might arise from phase control instabilities associated with transmit start up or from abrupt changes in phase at the beginning of transmit signal generation. A transmitter uses starting phase values in advance of transmit data phase values to initialize phase modulation control circuits or functions. Once phase control is stabilized, and possibly after other criteria are met, the transmitter transitions from using the starting phase values to using the transmit data phase values, so that a transmit signal begins carrying phase modulations associated with the desired transmit data.
    Type: Grant
    Filed: September 25, 2001
    Date of Patent: May 16, 2006
    Assignee: Ericsson Inc.
    Inventors: Cong Nguyen, Randy Bright
  • Patent number: 7046721
    Abstract: A method and apparatus encodes data on a clock pulse signal by phase modulating a clock pulse signal by introducing a sinusoidal jitter modulation to the clock pulse signal to selectively introduce intentional jitter at clock pulse transitions, wherein the sinusoidal jitter has selectable jitter frequencies each having a given amplitude. This is followed by a data signal which may include additional data that has an encoded format of binary ones and zeros, such that the appearance of the binary one in the data signal causes the phase modulation of the clock pulse signal by the selection of one of the jitter frequencies of a given amplitude. The appearance of a binary zero causes the selection of another frequency of a given amplitude to thereby modulate the clock pulse signal resulting in a phase modulated clock pulse signal that includes the encoded data in the data or additional signal.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: May 16, 2006
    Assignee: Ericsson Inc.
    Inventor: Ossi Ilari Grohn