Intel Corporation

Omnipoint Corporation

Siemens Communications, Inc.

Xircom, Inc.

Omnipont Corporation

Robert L Monroe

James P Kardach

Krishnan Rajamani

Logan Scott

Gordon Chinn

Narayan Parappil Menon

Randolph L Durrant

Timothy J Lunn

Randy Durrant

Francis A Gay

Methods and apparatus are disclosed for communicating via a radio channel to reduce radio frequency (RF) interference between transceiver systems within an electronic device.

Method and apparatus for communication using multiple communication protocols

Methods and apparatus are disclosed for mitigating radio frequency interference between transceiver systems within an electronic device.

Method and apparatus for mitigating radio frequency interference between transceiver systems

A method for providing user notification includes generating a mobile-terminated message containing at least a portion of information to be provided to a mobile station. The method also includes communicating the mobile-terminated message to a base station. The base station is operable to communicate the mobile-terminated message to the mobile station. The method further includes determining if the mobile station acknowledges successful receipt of the mobile-terminated message. In addition, the method includes generating a mobile-originated message containing at least a portion of the information for communication to a public network if the mobile station fails to acknowledge successful receipt of the mobile-terminated message. The public network is operable to communicate the mobile-originated message to the mobile station.

System and method for user notification in a communication system

In a first embodiment of the invention, a concatenated preamble code is formed by a kronecker product between two subcodes of the same or different lengths. The subcodes have favorable correlation properties and may be Barker codes, minimum peak sidelobe codes, Gold codes, Kasami codes, Boztacodes, or other codes. At the receiver a two-stage processor is used to detect the concatenated preamble code. The two-stage processor comprises a series of two filters, one of which is preferably a mismatched filter. In another aspect of the invention, a repeated codeword preamble is formed from a series of the same repeated short subcode. The short subcode may be an augmented or truncated odd-length code. At the receiver a single matched filter is preferably used to generate a series of spikes separated by the period of the subcode. An alert/confirm detector non-coherently adds together individual correlation spikes and reject false alarms. The alert function measures total correlation energy and adjusts detection thresholds based thereon, while the confirm function ensures that the proper number of correlation spikes exceed a detection threshold at the correct times. The preamble codes and their means for detection are preferably employed in a TDMA spread spectrum communication system, wherein a plurality of user stations communicate with a base station, one in each time slot (or virtual time slot).

Preamble code structure and detection method and apparatus

A technique for modulating and demodulating CPM spread spectrum signals and variations of CPM spread spectrum signals uses a set of codes or multiple sets of codes that reduce cross-correlation interference. A transmitter divides a signal data stream into I and Q data streams, independently modulates the I and Q data streams using CPM or a related technique, and superposes the plurality of resultants for transmission. A receiver receives the superposed spread spectrum signal, simultaneously attempts to correlate for I and Q chip sequences, and interleaves the correlated I and Q data streams into a unified signal data stream. In one embodiment the receiver separates the received spread spectrum signal into real and imaginary parts, attempts to correlate both real and imaginary parts for a plurality of chip sequences, and combines separate correlation signals into a unified signal data stream. In other embodiments single-bit or multi-bit digitization of the received spread spectrum signal is carried out prior to correlation. In another embodiment the transmitter differentially phase encodes the information to be transmitted, and the receiver decodes the phase-encoded information.

Spread spectrum codes for use in communication

In a first embodiment of the invention, a concatenated preamble code is formed by a kronecker product between two subcodes of the same or different lengths. The subcodes have favorable correlation properties and may be Barker codes, minimum peak sidelobe codes, Gold codes, Kasami codes, Boztas codes, or other codes. At the receiver a two-stage processor is used to detect the concatenated preamble code. The two-stage processor comprises a series of two filters, one of which is preferably a mismatched filter. In another aspect of the invention, a repeated codeword preamble is formed from a series of the same repeated short subcode. The short subcode may be an augmented or truncated odd-length code. At the receiver a single matched filter is preferably used to generate a series of spikes separated by the period of the subcode. An alert/confirm detector non-coherently adds together individual correlation spikes and reject false alarms. The alert function measures total correlation energy and adjusts detection thresholds based thereon, while the confirm function ensures that the proper number of correlation spikes exceed a detection threshold at the correct times. The preamble codes and their means for detection are preferably employed in a TDMA spread spectrum communication system, wherein a plurality of user stations communicate with a base station, one in each time slot (or virtual time slot).

In a first embodiment of the invention, two sets of seven PN-sequences of length 128 are provided having favorable correlation properties for use as a preamble or midamble synchronization code. At the receiver a processor may be used to detect the code. In another aspect of the invention, a communication system using a synchronization code selected from sets of provided codes is claimed where the synchronization code may help to minimize possible misidentification of noise or interference by assisting in the detection of the start of a designated burst. The synchronization codes and their means for detection may be employed in various communication systems.

Growing community of inventors

Colorado Springs, CO, United States of America

Robert L Monroe