Patents Represented by Attorney, Agent or Law Firm Richard A. Sonnentag
  • Patent number: 6038263
    Abstract: Different orthogonal codes (W.sub.x, W.sub.y) are used to spread common pilot channels (Pilot.sub.A) intended for transmission to a particular mobile station (106) within a coverage area (sector A) to implement forward link transmit diversity. By implementing separate, different orthogonal codes (W.sub.x, W.sub.y) for each pilot channel (Pilot.sub.A), the pilot signals transmitted via antennas (218, 222) to a common coverage area (sector A) are orthogonal to one another and thus do not degrade system performance. Additionally, the use of different orthogonal codes (W.sub.x, W.sub.y) for each pilot channel (Pilot.sub.A) allows the mobile station (106) to discern which pilot channel spread with a different orthogonal code includes corresponding traffic channel (TCH) information. This allows forward link transmit diversity to be enable/disabled based on conditions associated with the environment, the communications channel, etc. without a complete loss of information as seen by the mobile station (106).
    Type: Grant
    Filed: July 31, 1997
    Date of Patent: March 14, 2000
    Assignee: Motorola, Inc.
    Inventors: Michael D. Kotzin, Walter J. Rozanski, Jr.
  • Patent number: 6018544
    Abstract: Subscriber power levels are adjusted to enhance interference cancellation in a DS-CDMA communication system. A base-station of the communication system receives signals from a plurality of subscribers and evaluates each signal. Based on the evaluation, particular subscribers are commanded to control their power levels such that different predetermined targets for the particular subscribers are maintained. The predetermined targets include, but are not limited to, received power, frame erasure rate, bit error rate and signal quality. The resulting power levels received at the base-station are substantially different, which is beneficially employed to enhance interference cancellation in the DS-CDMA communication system.
    Type: Grant
    Filed: October 21, 1996
    Date of Patent: January 25, 2000
    Assignee: Motorola, Inc.
    Inventors: Michael D. Kotzin, Reuven Meidan
  • Patent number: 5991262
    Abstract: A peak-reducing waveform is estimated and summed with a composite signal to reduce the peak-to-average power ratio of the composite signal. The estimate of the peak-reducing waveform is modified to have Walsh code components orthogonal to the assigned Walsh codes. An iterative process of estimating subsequent peak-reducing waveform is implemented to produce a peak-reducing waveform which, when summed with the composite signal, results in a composite signal having a peak-to-average ratio at a desired level and thus does not have the effects of remodulating the assigned Walsh codes. Constraints on the magnitude of the unassigned Walsh code components can be included for controlling the power level under the unassigned Walsh codes.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: November 23, 1999
    Assignee: Motorola, Inc.
    Inventors: Kevin Michael Laird, Jack Anthony Smith
  • Patent number: 5974325
    Abstract: A communication system employs a method and apparatus for exchanging communicated signals between a communication unit (e.g., 17) and a central site (205). A remote base site (65) or the central site (205) determines whether a signal must be exchanged between the communication unit (17) and the central site (205). When a signal is to be exchanged, the remote base site (65) allocates a first radio frequency communication resource (75) for use in exchanging the signal between the communication unit (17) and the remote base site (65) and a second radio frequency communication resource (74) for use in exchanging the signal between the remote base site (65) and the central site (205).
    Type: Grant
    Filed: March 6, 1995
    Date of Patent: October 26, 1999
    Assignee: Motorola, Inc.
    Inventors: Michael D. Kotzin, Valy Lev, Stephen Lee Spear, John Stephen Ruppel
  • Patent number: 5970058
    Abstract: A mobile station (106) in a code division multiple access (CDMA) communication system (100) implements scanning of pilot channels on a different frequency by reserving a periodic frame on the forward channel to allow the mobile station (106) to change frequencies and scan for other pilot channels. To preserve some aspects of voice quality, both the base station (102) and mobile station (106) voice encode speech at a maximum of half rate and transmit the information as secondary traffic prior to the frame where the mobile station (106) scans the alternate frequency. To maximize the trade-off between voice quality and frequency of the scan, the base station (102) indicates to the mobile station (106) the period between other frequency scans via messaging. To ensure compatibility, this method can be negotiated via known service configuration negotiation techniques.
    Type: Grant
    Filed: April 12, 1997
    Date of Patent: October 19, 1999
    Assignee: Motorola, Inc.
    Inventors: Daniel J. DeClerk, James P. Ashley
  • Patent number: 5949771
    Abstract: At the beginning of handoff processing at a target base-station, the duplicate message detection mechanism within the layer 2 (L2) signaling layer is disabled such that the target base-station processes all received messages. When the target base-station receives and processes a Handoff Completion message, the target base-station resets all of it's duplicate detection flags to the L2 state at the start of a communication (call) except for the Handoff Completion message itself. The acknowledgment sequence number within L2 is then set to the message sequence number sent within the received Handoff Completion message. Since L2 synchronization is provided when the acknowledgment sequence number and the message sequence number are common, all acknowledgments via L2 are sent after hard handoff is completed.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: September 7, 1999
    Assignee: Motorola, Inc.
    Inventors: Daniel J. DeClerck, John P. Nolting
  • Patent number: 5943376
    Abstract: A method and system for time aligning a frame (60) in a communication network (10) involves the steps of; i) determining if a frame needs to be advanced at a BTS (14), and ii) sending a shortened synchronization pattern from the BSC (12). The BTS (14) then determines if a short or long synchronization pattern has been sent by determining (256) if the received data stream matches a long synchronization pattern and setting a first flag when they do match. If the received data stream does not match the long synchronization pattern and the first flag is set (264), the data stream is compared (266) to the short synchronization pattern. When they match a second flag is set (268).
    Type: Grant
    Filed: April 6, 1995
    Date of Patent: August 24, 1999
    Assignee: Motorola, Inc.
    Inventors: Lee Michael Proctor, Quoc Vinh Nguyen, Gino Anthony Scribano, Gregory Keith Wheeler
  • Patent number: 5926761
    Abstract: A wireless communication system (200) estimates (303) the location of a mobile station (215) when a degradation in the mobile station's communication occurs due to interference, and stores (305) the location estimate in a database. The database is used to determine the potential for the mobile station (215) within the wireless communication system to receive interference based on its estimated location or its proximity to the known interference location. When the mobile station (215) is within a predetermined distance of the known interference location, the likelihood for the mobile station (215) to experience a degradation in call quality, duration, etc. increases. To mitigate the degradation due to interference, an alternate carrier (104) is found and if available, the mobile station's communication is handed off to the alternate carrier (104). Attenuation can also be added in the front-end of the mobile station (215) to mitigate the degradation due to interference.
    Type: Grant
    Filed: June 11, 1996
    Date of Patent: July 20, 1999
    Assignee: Motorola, Inc.
    Inventors: John Douglas Reed, Walter Joseph Rozanki, Jr.
  • Patent number: 5923214
    Abstract: A feedforward amplifier network (42) generates a fixed offset frequency swept pilot tone (46) over at least the same frequency band as an input signal (40). The fixed offset frequency swept pilot tone (46) is a function of a variable frequency reference signal (52) and a fixed pilot tone clock signal (54). A mixer arrangement (66 and 70), as opposed to a phase lock loop arrangement, helps ensure that the fixed frequency offset can be generated over the swept range. In addition, the feedforward amplifier network (42) incorporates a delay (58) which is added to the variable frequency reference signal (52) and used by a pilot tone detector (57) so that the pilot tone generator (44) and pilot tone detector (57) are in synchronization over narrow bands to accommodate pilot tone detection in the presence of code division multiple access channels that are relatively close together.
    Type: Grant
    Filed: December 17, 1997
    Date of Patent: July 13, 1999
    Assignee: Motorola, Inc.
    Inventor: James E. Mitzlaff
  • Patent number: 5905757
    Abstract: A filter co-processor within a Digital Signal Processor (DSP) takes advantage of the orthogonal nature of modulated signals during the equalization process. Since, after reception, only certain real/imaginary values of the received signal are useful for demodulation, the filter co-processor only processes those values to estimate the transmitted signal. By processing only those values useful for demodulation, the filter co-processor is able to process more information in a given amount of time, leading to increased processing when compared to the prior art.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: May 18, 1999
    Assignee: Motorola, Inc.
    Inventors: Thomas Kundmann, Mack Mansouri, Moshe Tarrab, Eran Pisek
  • Patent number: 5901354
    Abstract: Generally stated, a method for performing soft-handoff within a wireless communication system 100 is described herein. The wireless communication system 100 includes, inter alia, a mobile station 104, a first base station 102 in communication with said mobile station via a first communication resource 120, and a second base station 106 with a corresponding second communication resource 130. In a first preferred embodiment, a determination is made that the first communication resource 120 is no longer necessary. The wireless communication system 100 verifies that the second base station 106 has acquired the mobile station 104 via the second communication resource 130. If the second base station 106 has yet to acquire the mobile station 104 on the second communication resource 130, the wireless communication system 100 will override the normal power control mechanisms, increasing the mobile station's 104 transmit power, thereby mitigating the opportunity for an orphan condition to develop.
    Type: Grant
    Filed: April 3, 1996
    Date of Patent: May 4, 1999
    Assignee: Motorola, Inc.
    Inventors: Barry J. Menich, Keith A. TenBrook, Thomas W. Ritchie, Daniel J. DeClerck
  • Patent number: 5901351
    Abstract: A method and apparatus for fraud detection is provided in which a remote unit within a communication system (100) transmits a Digital Supervisory Audio Tone (DSAT) at a transmission rate with a known maximum phase shift over time. When a fraudulent remote unit hijacks a traffic channel within the communication system (100), fraud detection is accomplished by calculating a maximum permitted (DSAT) phase shift (630) and determining if the reacquired DSAT has a phase shift greater than a permitted DSAT phase shift (635). When a reacquired remote unit's DSAT phase shift is greater than a permitted DSAT phase shift, appropriate fraud control methods are performed (640).
    Type: Grant
    Filed: May 22, 1996
    Date of Patent: May 4, 1999
    Assignee: Motorola, Inc.
    Inventor: W. Daniel Willey
  • Patent number: 5883897
    Abstract: A mobile station (115) and its supporting infrastructure equipment negotiate service configurations based on the service option capabilities of both the mobile station (115) and the infrastructure equipment. This negotiation process is performed via a traffic channel which is primarily intended for carrying vocoded voice information. The infrastructure equipment manages the capabilities of the transcoder circuits and checks the transcoder availability before proposing or accepting a particular service configuration. When a mutual service configuration is reached, the infrastructure equipment reallocates a new transcoder circuit based on its service option capability and the precheck of the transcoder availability and informs the mobile station (115) when to reset its layer 2 (L2) sequence number via an ACTION.sub.-- TIME parameter. After switching transcoders, the infrastructure equipment and the mobile station (115) reset their respective sequence numbers at the ACTION.sub.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: March 16, 1999
    Assignee: Motorola, Inc.
    Inventor: Harn-Jier Lin
  • Patent number: 5881093
    Abstract: A block interleaver (212) suitable for communication over fading channels with convolutionally coded signals as input is disclosed. The block interleaver (212) implements multiple interleaving distances which are matched to the particular convolutional code to provide better performance than conventional block interleavers.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: March 9, 1999
    Assignee: Motorola, Inc.
    Inventors: Michael M. Wang, Fuyun Ling
  • Patent number: 5878098
    Abstract: A method of determining a rate associated with a received signal including the steps of detecting the received signal (40); decoding the received signal at a first rate, determining a first path metric associated with the first rate, decoding the received signal at a second rate, and determining a second path metric associated with the second rate (44); calculating a plurality of discriminant functions based on the first and second path metrics (46); comparing at least one of the plurality of discriminant functions to a first predetermined value (48); and selecting one of the first and second rates as a determined rate based on the comparison.
    Type: Grant
    Filed: June 27, 1996
    Date of Patent: March 2, 1999
    Assignee: Motorola, Inc.
    Inventors: Michael M. Wang, Fuyun Ling, Terry M. Schaffner
  • Patent number: 5867064
    Abstract: A feed-forward amplifier (600) has an error path (123) replaced by a feed-forward amplifier (603) in a nested feed-forward configuration. By replacing the error path (123) with the feed-forward amplifier (603), design parameters such as efficiency and power output which are difficult to achieve with the conventional error path (123) are easily achieved with the single loop feed-forward amplifier (603). In this configuration, the main path (613) of the feed-forward amplifier (603) is capable of operating in a more efficient Class AB mode while still operating over a large dynamic range with to provide a relatively constant gain/phase relationship, thus insuring good intermodulation performance. The error path (627) of the feed-forward amplifier (603) must still be biased Class A, but it's requirements are much less than those of a Class A error amplifier (124) in an un-nested configuration.
    Type: Grant
    Filed: August 19, 1996
    Date of Patent: February 2, 1999
    Assignee: Motorola, Inc.
    Inventors: Mark I. Van Horn, Joe Clark, Leroy Plymale
  • Patent number: 5862488
    Abstract: A controllable playback device is placed in a mobile station (125) which is capable of playing a recorded announcement to the user of the mobile station (125) when activated by the infrastructure equipment of the cellular communication system. The cellular communication system determines if a voice channel is available (506), and if unavailable, an estimate of a retry time period is performed (512). After the estimate of the retry time period, the system forms and sends a message to the mobile station (125) including the retry estimate (515). The mobile station (125) receives the message, and activates the controllable playback device to announce to the user of the mobile station (125) that the system is fully loaded and that an access attempt at a time related to the retry estimate would likely be successful.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: January 19, 1999
    Assignee: Motorola, Inc.
    Inventors: Michael D. Kotzin, Philip J. Fleming
  • Patent number: 5862190
    Abstract: A decoder (215) implemented in a receiver of a wireless communication system employs an improved method and apparatus for decoding an encoded signal. The receiver sums the energy values (156A, 156B, . . . 156N) from a plurality of fingers within to produce an aggregate energy value (166). From the aggregate energy value (166), a set of log-likelihood values (207) are generated with a non-linear function generator (205) before being deinterleaved by a deinterleaver (210). The deinterleaved values (213) are input to the decoder (215) which estimates the original signal (178) by incorporating path histories of bits in the estimation of subsequent, related bits. Use of the path histories of bits improves the estimates of the original signal (178), which translates into an increase in the sensitivity of the receiver.
    Type: Grant
    Filed: December 29, 1995
    Date of Patent: January 19, 1999
    Assignee: Motorola, Inc.
    Inventor: Terry Michael Schaffner
  • Patent number: 5854571
    Abstract: An apparatus and method of reducing a peak envelope power of a linear power amplifier (10) amplifying a plurality of channels is provided. The method includes the steps of measuring (104) the peak envelope power of the linear power amplifier, measuring a channel activity level (101) of each channel of the plurality of channels, and, when the peak envelope power exceeds a first threshold, changing (103, 106) at least one parameter of a channel of the plurality of channels having a channel activity level exceeding a second threshold to reduce the peak envelope power.
    Type: Grant
    Filed: October 28, 1993
    Date of Patent: December 29, 1998
    Assignee: Motorola Inc.
    Inventors: Danny Thomas Pinckley, Kevin Michayl Laird, Charles N. Lynk, Jr.
  • Patent number: 5855003
    Abstract: A base station system (203, 303) in a wireless communication system (208, 308) establishes a link between a mobile station (200, 300) and a speech recognition system (209, 312). When the base station system (203, 303) determines that such a connection is required, the base station system (203, 303) instructs the mobile station (200, 300) to switch from a first codec (201) specific to human speech to a second codec (202) specific to speech recognition. Only after the switch between codecs in the mobile station (200, 300) does the base station system (203, 303) establish the link between the mobile station (200, 300) and the speech recognition system (209, 312).
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: December 29, 1998
    Assignee: Motorola, Inc.
    Inventors: Gregory C. Ladden, Eugene J. Bruckert