Motorola Corporation

General Dynamics C4 Systems, Inc.

General Dynamics Decision Systems, Inc.

General Dynamics Corporation

Motrola, Inc.

Chad Scott Bergstrom

John Eric Kleider

Jeffery Scott Chuprun

Bruce Alan Fette

Byron Tarver

Sean S You

Carl Steven Gifford

Jeffrey Scott Chuprun

Bennett Charles Beaudry

Clifford A Wood

Cynthia Ann Jaskie

Richard James Pattison

Hugh Robert Malone

Glen Patrick Abousleman

William Michael Campbell

Ghassan Maalouli

Charlene Jean Todd

Steve Henry Arneson

Amy Michelle Guzek

F Elvin Krasin

Sue E Sprute

Sidney Clarence Garrison, Iii, Deceased

Michael Eugene Humphrey

Jeffrey Scott Churprun

A method () of orthogonal frequency-division multiplex (OFDM) communication via a plurality of subchannels () within a noncontiguous wideband channel () is provided. The method () determines an SNR for each of the subchannels (). The method () then designates a subchannel () as clear () when its SNR is greater than a least-SNR threshold (), as impeded () when its SNR is less than the least-SNR threshold and greater than an SNR-evaluation threshold, and as obstructed () when its SNR is less than both the least-SNR and the SNR-evaluation thresholds. The method () then transmits OFDM data () so that each of the clear subchannels receives the OFDM data () at a maximum subchannel signal level (), each of the impeded subchannels receives the OFDM data () at an intermediate subchannel signal level (), and each of the obstructed subchannels receives the OFDM data () at zero subchannel signal level ().

Method of multiple-carrier communication within a noncontiguous wideband spectrum and apparatus therefor

A high speed data transfer system includes a WAU () which is utilized to provide high speed access to satellite transferred data. The system is configured such that a plurality of data utilization () may access the high speed data via wireless links to the WAU (). Advantageously, high speed data services may be provided to users without the users requiring individual satellite antennas.

Satellite based data transfer and delivery system

Apparatus are provided for a communication signal processing apparatus having a channel estimator configured to generate a first channel estimation at a first time point, a linear predictor coupled to the channel estimator, and an adaptive filter coupled with the linear predictor. The linear predictor is configured to predict a second channel estimation based on a second time point and a channel frequency. The second time point is concurrent or subsequent to the first time point. The second channel estimation includes a first coefficient. The linear predictor includes a first predictor having a sample time point. The first predictor is configured to generate the first coefficient of the second channel estimation based on the sample time point and the second time point. The sample time point is prior to the second time point. The adaptive filter is configured to recursively determine the second channel estimation.

Communication channel tracking apparatus

A symbol synchronizer () is provided for a software-defined communications system (). The symbol synchronizer (), when integrated into either a pre- or post-detection diversity signal combiner (), enables highly accurate signal synchronization with minimal added system complexity. The symbol synchronizer () includes a single complex sliding window-matched filter () for filtering an input digital signal with a match filtering function based on predetermined signal transfer function characteristics to average out receiver noise from the signal. A signal delay bank () includes a plurality of delay blocks each for delaying the digital signal filtered by the single matched filter for a predetermined number of samples. A complex correlator () correlates the digital signal filtered by the single complex sliding window matched filter () and delayed by the complex correlator () with a correlator reference signal, and selects an index of a path having a peak correlator value. As a result of such a configuration, the symbol synchronizer () is capable of determining symbol boundaries of channel signals in a multi-channel communications system to enable system signal measurement statistics and demodulated to be more accurately generated.

Symbol synchronizer for software defined communications system signal combiner

An embodiment of a method for parameterizing an input signal includes non-linearly transforming the input signal, removing higher order terms by passing the input signal through a low pass filter to produce a linear combination of data symbols and DC components, solving for the DC components, separating a plurality of mixed baseband signals from the input signal, and coordinate transforming each of the separated signals from polar coordinates to Cartesian coordinates. An embodiment of a receiver includes a non-linear transform operator receiving a digitized input signal and adapted to produce a linear combination of data symbols, DC components, and carrier effects; a low-pass filter for removing higher order terms; a separator unit for separating the plurality of mixed baseband signals; and a coordinate transform for converting the separated signals from polar coordinates to Cartesian coordinates.

Method and apparatus for signal separation

Methods and apparatus are provided for distributed polyphase spread spectrum communication and non-contiguous spectrum underlay. The method includes polyphase channelizing a direct sequence spread spectrum (DSSS) signal, determining available spectrum in an observed frequency range having a noise floor based on detection of polyphase users below the noise floor, distributing the polyphase channelized signal among the available spectrum, and interference mitigation using a combination of standard signal detection and cyclostationary feature detection methods. The apparatus includes: a first processor adapted to polyphase channelize a code division multiple access (CDMA) spectrum and a digitized RF bandwidth containing a discontiguous polyphase waveform distribution; a second processor adapted to detect occupied bands, interferers and polyphase users in a spectrum and determine discontiguous frequency opportunities based on the detected interferers and polyphase users; and a third processor adapted to allocate the polyphase channelized CDMA spectrum among available spectrum based on the discontiguous frequency opportunities.

Method and apparatus for distributed polyphase spread spectrum communications

A symbol synchronizer ( ) is provided for a software-defined communications system ( ). The symbol synchronizer ( ), when integrated into either a pre- or post-detection diversity signal combiner ( ), enables highly accurate signal synchronization with minimal added system complexity. The symbol synchronizer ( ) includes a single complex sliding window matched filter ( ) for filtering an input digital signal with a match filtering function based on predetermined signal transfer function characteristics to average out receiver noise from the signal. A signal delay bank ( ) includes a plurality of delay blocks each for delaying the digital signal filtered by the single matched filter for a predetermined number of samples. A complex correlator ( ) correlates the digital signal filtered by the single complex sliding window matched filter ( ) and delayed by the complex correlator ( ) with a correlator reference signal, and selects an index of a path having a peak correlator value. As a result of such a configuration, the symbol synchronizer ( ) is capable of determining symbol boundaries of channel signals in a multi-channel communications system to enable system signal measurement statistics and demodulated to be more accurately generated.

A high speed data transfer system includes a WAU ( ) which is utilized to provide high speed data access to satellite transferred data. The system is configured such that a plurality of data utilization devices ( ) may access the high speed data via wireless links to the WAU ( ). Advantageously, high speed data services may be provided to users without the users requiring individual satellite antennas.

A communications system ( ) includes a multi-rate source coder (MRSC) ( ), a variable size/rate buffer (VSRB) ( ), a speech buffer ( ), and a buffer control block ( ). The variable size/rate buffer ( ) includes a source coder bit buffer (SCBB) ( ) and an adaptive transmit frame buffer ( ). The source coder bit buffer ( ) receives speech frames coded at different rates from the multi-rate source coder ( ), and deposits an integer or non-integer number of frames in the adaptive transmit frame buffer (ATFB) ( ). A receiver includes a seamless rate transition module (SRTM) ( ) and an variable buffer ( ). The seamless rate transition module ( ) correlates speech data previously coded at different rates, and it then truncates or alternatively appends, concatenates, and warps the speech data to remove any annoying artifacts at the rate change boundary.

Method and apparatus for seamless multi-rate speech coding

An orthogonal frequency division multiplexed wideband communication system provides improved time and frequency synchronization by inserting an unevenly spaced pilot sequence within the constellation data. A receive correlates the received data using the unevenly spaced pilot sequence. The pilot sequence is generated with a maximum length pseudo random noise code and inserted into frequency bins having prime numbers.

Wireless communication system and method for synchronization

A wireless access unit ( ) for providing an interface between a satellite communications system ( ) and a plurality of terrestrial user devices ( ) in a centralized or distributed architecture includes a spectrum allocation unit ( ) for dynamically allocating spectrum to the plurality of terrestrial user devices ( ) based on a spectral environment about the wireless access unit ( ). A spectrum scan unit ( ) scans the spectral environment about the wireless access unit ( ) and generates a spectrum signal indicative thereof. An environment understanding unit ( ) provides signal information corresponding to signal emitters in proximity to the distributed or centralized network. A spectrum table ( ) assembles data related to the spectral environment and the proximity emitters for use by the spectrum allocation unit ( ) in dynamically allocating spectrum.

Wireless access unit utilizing adaptive spectrum exploitation

An apparatus is disclosed for continuous load optimization of wireless communication networks by making use of statistical data about both the communication medium characteristics and the characteristics of messages that users desire to send over the network. The network comprises a network control base station ( ) and a plurality of slave stations ( ). One or more applications ( ) are associated with each station which are used to generate the messages in digital format. Each application is coupled to a protocol stack ( ) that defines the required characteristics of the data and changes to the data that occur during the communication process. An interface ( ) is coupled to the layers of each protocol stack ( ) to allow tuning of the message characteristics to maximize successful transmission with minimum message latency.

Method and apparatus for asynchronous adaptive protocol layer tuning

A non-linear signal classifier (,) includes a polynomial expansion unit for expanding signal feature vectors determined by a feature extraction unit (,) for a received signal. The expanded signal feature vectors are each combined with a plurality of signal classification models that are stored in a model memory (,). The signal classification models are each associated with a particular signal type that is recognized by the non-linear signal classifier. A scoring unit (,) generates a score for each of the signal classification models based on the result of the combination. The scores are analyzed by a selection unit (,) which determines which of the signal classification models (i.e., which of the signal types) most likely represents the received signal. Training equipment (,) is also provided for training the non-linear signal classifier (,) to recognize new signal types. In one embodiment, the training equipment (,) is capable of adding a new signal classification model to the model memory (,) without modifying other models stored therein.

Apparatus for performing non-linear signal classification in a communications system

The invention relates to a communication system (300) having a receiver (304) that is capable of performing targeted interference suppression. An interference classifier (314) within the receiver (304) analyzes a signal received from a channel (306) and identifies and classifies interference components within the signal. An interference suppressor (316) then suppresses the interference components in the signal based on interference type. In one embodiment, the interference suppressor (316) includes a plurality of interference suppression modules that are each optimal for suppressing certain interference types. The interference suppressor (316) selects one of the interference suppression modules based on the type of interference present in the received signal. In another embodiment, a hybrid interference mitigation system (10) is provided by combining targeted interference suppression, frequency hopping adaptation, and processing gain adaptation.

Method and apparatus for performing targeted interference suppression

The invention relates to a communication system (300) having a receiver (304) that is capable of performing targeted interference suppression. An interference classifier (314) within the receiver (304) analyzes a signal received from a channel (306) and identifies and classifies interference components within the signal. An interference suppressor (316) then suppresses the interference components in the signal based on interference type. The interference suppressor (316) includes a plurality of interference suppression modules that are each optimal for suppressing certain interference types. In one embodiment, one or more of the interference suppression modules perform interference suppression using modal moment estimates to identify different modes within the signal.

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Chandler, AZ, United States of America

Chad Scott Bergstrom