Pacific Communication Sciences, Inc.

Conexant Systems, Inc.

Cirrus Logic Inc.

Other

Adc Telecommunications, Inc.

Viasat, Inc.

Coppergate Communications Ltd.

M/a-com Government Systems, Inc.

Pacific Communication Systems, Inc.

Steven H Gardner

James E Petranovich

Carl Thomas Hardin

Seton Paul Kasmir

Sheldon L Gilbert

Kumar Balachandran

Mark T Robinson

Gail Schjelderup

Sue Graham

Matt Wong

Roy Franklin Quick, Jr

Franklin Peter Antonio

Garold B Gaskill

Deepak V Ayyagari

Daniel Park

Roy F Quick

Neal Riedel

Naom Chaplik

William A Shumate

Daniel Ray Kindred

Yiorgos M Peponides

Krishnanand Kelkar

Steven L Rogers

C Thomas Hardin

Thomas R Bilotta

A data transmission method and apparatus are disclosed using receivers having spatial diversity, with the receivers communicating with a common client via network communication. Improved systems and methods for data transmission according to the disclosed method and apparatus include at least: a transmission source for transmitting a data signal; a first receiver for receiving the data signal; a second receiver for receiving the data signal, wherein the second receiver is spaced apart from the first receiver thereby providing spatial diversity; and a communication network for facilitating communication between a client and at least the first receiver and the second receiver, as needed, wherein the client is capable of analyzing individual data signals received by the first and second receivers and forming a composite signal of a higher quality than the quality of the individual data signals.

Data transmission method and apparatus using networked receivers having spatial diversity

A method for establishing a circuit connection over a network. Determining a channel quality profile of a medium connecting a source node and a destination node. Determining a throughput required to support a data rate requirement of an application that sources data. Determining a modulation type and modulation density at one or more frequency according to the channel quality profile. Selecting one or more of a set of frequencies, modulation types and modulation densities to support the throughput. Communicating the selection to nodes attached to the medium.

Method and apparatus for establishing circuit connections over local area networks with frequency selective impairments

Provided is a frame structure for filtered OFDM signaling, wherein once every frame a central controller passes redundant broadcast data for a short time (e.g. 16 symbol times) over all frequencies in use. This broadcast, called a beacon, may carry control information, frame structure information, and other data. The rest of the frame is divided into other assignments, including broadband redundantly coded channels for broadcast, ALOHA contention access, or point-to-point transmissions, and including traffic channels that may use only some of the assigned frequencies intended primarily for point-to-point access. This allows a mix of TDMA and FDMA point-to-point and broadband access. This system may be controlled by a central coordinator, which issues reservations. This system allows devices on a frequency-selective channel to communicate with scheduled operations.

Frame structure for OFDM signaling, including beacons and traffic

Disclosed are a method and apparatus for generating a controlled spectrum of modulated energy. A single data stream is splintered into substreams. Each substream is used to modulate a portion of the modulated spectrum. Each substream is transformed into a numerical phase and amplitude representation of a portion of the spectrum to be modulated. The combined numerical representations are then converted to a time-domain representation and filtered to eliminate undesired side-lobes.

Method and apparatus for controlled spectrum multi-carrier modulation

Local area network bandwidth is partitioned into periodic data frames. Data frames are further segregated into spectrum and time slots. Bandwidth reserved by assigning spectrum and time slots to particular circuit connections; enabling deterministic data transfer from source to destination nodes. Bandwidth reservations are broadcast to nodes attached to network.

The modulation method and system of the presented herein involves mapping data onto a constellations comprising a set of concentric circles in a two-dimensional plane, one dimension for the amplitude and one for the phase. The phase dimension is coded differentially, while the amplitude dimension is coded coherently. The circles in each constellation may contain equal number of points, and in other embodiments more points may be used on the outer circles. The data may be coded with dual Trellis codes, one code for the phase data and another code for the amplitude data.

Circular constellations with coherent gain/differential phase and pilots

A novel method and apparatus for preamble detection and time synchronization estimation in OFDM communication systems is described. The present invention can be easily implemented to provide preamble detection and highly accurate time synchronization estimations. The inventive method and apparatus utilizes phase and magnitude information obtained from a received signal to detect a preamble and to calculate a time synchronization estimation for the received signal.

Method and apparatus for preamble detection and time synchronization estimation in OFDM communication systems

An inventive Medium Access Control (MAC) protocol for powerline networking systems is described. The inventive MAC protocol controls access to and use of a physical medium (power lines) in a powerline networking system. The MAC protocol method and apparatus includes a method of providing 'blanking intervals' in which devices using newer versions of the protocol 'clear out' earlier version devices. The use of blanking intervals greatly eases backward compatibility of the network when the protocol is upgraded with new versions. The method of using blanking intervals is closely coupled to a technique of using &#x201c;beacons.&#x201d; The beacons are used to propagate blanking interval information throughout the network. The beacons also include a mechanism for informing devices of the expiration of blanking information. The MAC also includes a method of establishing and maintaining &#x201c;virtual circuit&#x201d; connections between selected devices on the network. The virtual circuits can be established in powerline networking systems not having a central controller. A method of assigning unique Logical Network Identifiers (LNIs) to logical networks in the powerline networking system is also described. The LNIs uniquely identify each of the logical networks in the network. A means for creating, managing and distributing network encryption keys is also described. The encryption keys are used by the devices in the powerline networking system to prevent data from being shared with unauthorized users.

Method and apparatus for medium access control in powerline communication network systems

A multi-mode communication system, including controller, base stations and subscriber stations, where the communication system has the capability of operating either in a packet-switched mode or a circuit-switched mode. The packet-switched mode of operation complies with the existing Cellular Digital Packet Data (CDPD) standard with respect to modulation and higher level protocol, and is designated continuous CDPD mode. This mode of operation is highly cost effective for transfers of relatively small amounts of data. For larger data transfers, the more cost-effective continuous CDPD mode is used. Thus, using this mode, the system is capable of providing superior data rate performance over a vastly greater coverage area than existing circuit-switched modems. Requests for access to continuous CDPD channels are initiated at subscriber stations. This initiation can result from manual intervention by the user of the subscriber station, or can be automatic in response to the amount of data to be transferred, as well as comprising structure for each mode of data transfer used by the service provider.

Continuous CDPD base station and method of facilitating efficient data transfer

A time sharing method and apparatus for frequency reuse in cellular communication systems. Frequency reuse is enhanced by synchronizing cell transmit/receive base stations in a cellular system to a common time base, and then sharing the available frequencies via allocated time slots. Cells using the same frequency that may interfere with each other are activated only during selected time intervals while same-frequency cells nearby are deactivated. The deactivated cells are then in turn activated while previously activated same-frequency cells nearby are deactivated. The frequency time slots may be of equal length, or longer time slots may be allocated to cells having higher usage rates, as determined in any of a number of ways. The time slots may be mutually exclusive, or may overlap. The time sharing technique of the present invention allows design of cell systems with many reuse patterns. Several particular cell reuse patterns are disclosed that provide good operational characteristics and low co-channel interference. The invention allows the use of a small number of cellular frequencies in a conventional cellular system without significant alteration of the existing system, and is particularly useful in two-way cellular paging systems. Improved reverse link data throughput is achieved via reuse of the reverse frequency channels.

Method and apparatus for frequency reuse in cellular communication systems

A cellular digital packet data (CDPD) system includes a mobile data base station (MDBS) configured to interface easily with an advanced mobile phone system (AMPS). The elements of the MDBS are arranged on modules and the functionality of the MDBS is divided among the modules to facilitate flexibility, compactness and quick expansion of the MDBS. To further facilitate compactness, the MDBS includes a transceiver/modem board which uses a single chip to carry out delta-sigma modulation. In order to maintain the integrity of CDPD transmission, a channel hopping scheme is used based upon avoidance of AMPS channel use. A distinctive protocol is used to encapsulate control/query/response data for transmission throughout the CDPD system. This protocol also facilitates easy control of each MDBS throughout the system.

Cellular digital packet data mobile data base station

A method and apparatus for efficient use of both power and bandwidth in a cellular communications system in which a Mobile Unit preferably enters Sleep-Mode when no communications have occurred between the Mobile Unit and the Base Station over a predetermined amount of time measured by an 'Idle Timer'. Upon expiry of a Wake Timer, the Mobile Unit awakes from Sleep-Mode to determine whether a message is pending. Concurrently, the Base Station transmits a 'TEI-Notification' message directed to all Mobile Units to notify each Mobile Unit that has data pending. A system parameter determines the intervals at which the Base Station will transmit these notifications. Upon waking to receive a TEI-Notification message, the Mobile Unit determines whether the quality of the transmission is at least sufficient to allow the Mobile Unit to decipher the TEI-Notification message. If this minimal requirement is met, and the TEI-Notification message does not indicate that data is pending for the Mobile Unit, the Mobile Unit returns to sleep, even though the Mobile Unit may reside in a cell other than the cell associated with the Base Station currently assigned by the IS to communicate with the Mobile Unit. The Mobile Unit of the present invention does not monitor the forward channels on a regular basis, but rather waits until either the signal quality of the forward channel over which the Mobile Unit is receiving has degraded such that the TEI-Notification message can no longer be deciphered, or the TEI-Notification message indicates that a message is pending.

Method and apparatus for low power mobile unit for cellular

Reverse channel reuse scheme in a time shared cellular communication

A synchronized frequency hopping method and apparatus for use in a cellular communication system where the cellular communication systems has a plurality of cells and a plurality of frequencies available to be assigned to the cells. At predetermined times, cells in the system synchronously change or hop to a new frequency. The new frequency to which a cell hops to may be a function of the present frequency the cell is assigned. In addition, synchronized frequency hopping may occur at predetermined intervals and the pattern of hopping may periodically repeat. This technique limits the period of time a non-system source of interference may impair communications in any cell since the cell hops to different frequencies periodically.

Synchronized frequency hopping

A method and apparatus for improving the signal-to-interference ratio and signal-to-noise ratio of a signal transmitted on a reverse channel from a mobile transmitter in a land mobile communications system by using a sectored cell in which the same channel is received by each sector of the cell. Each directional antenna is coupled to a unique associated receiver tuned to the same frequency or frequencies as the other receivers associated with each other directional antenna within the same sectored cell. Depending upon the location of the mobile end system with respect to the antenna pattern of each directional antenna, each signal will typically be redundantly received over more than one, but less than all, of the antennas. In accordance with the present invention, only one of the received signals is to be communicated from the base station to an intermediate system and all others are to be discarded. If multiple copies of the same message are received, then the control computer couples only one such copy to the intermediate system and discards each of the others.

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San Diego, CA, United States of America

Steven H Gardner