Abstract: Systems and methods for DC offset correction in analog and digital direct conversion RF receivers. A time derivate and subsequent integration of in-phase and quadrature phase signal path components is performed to effectively remove DC offset from the resultant down converted baseband signal.

Abstract: A coaxial orthomode transducer with improved port to port isolation, low higher order mode (“HOM”) coupling, and low transverse electromagnetic mode (“TEM”) coupling is disclosed.

Abstract: A base station (26) provides service in a satellite communications (SATCOM) system (22) to a terminal (24). The SATCOM system (22) operates in accordance with a first standard (43), and the terminal (24) is unable to communicate in accordance with the first standard (43). Methodology entails receiving, at a SATCOM resource controller (32), a request (62) for a satellite resource (46) from the base station (26). The satellite resource (46) is allocated to the base station (26) and the controller (32) sends a message (58) with the allocated satellite resource (46). The base station (26) applies a second standard (48), defining a specific set of functional and performance characteristics, to the satellite resource (46). The terminal (24) is enabled to perform satellite communications in accordance with the second standard (48) using the satellite resource (46).

Abstract: A dual-frequency conformal multi-filiar helical antenna system (20) provides a low-profile, low drag antenna useable in flying equipment. This antenna system (20) securely holds within its shell (22) signal distribution circuitry (64), signal combining circuitry (68), and any other circuit components necessary for antenna system (20) to communicate with other stations or devices. Antenna system (20) has radiating conductors (24, 32) tuned to two different frequencies such that simultaneous transmission and reception of signals is possible in the same and opposite directions.

Abstract: A high speed data transfer system includes a WAU (201) which is utilized to provide high speed access to satellite transferred data. The system is configured such that a plurality of data utilization (205) may access the high speed data via wireless links to the WAU (201). Advantageously, high speed data services may be provided to users without the users requiring individual satellite antennas.

Abstract: Techniques are provided for secure group communications in a wireless dispatch system which includes a group of devices. The group of devices can include a first secure device which communicates with a plurality of second secure devices over a channel.

Abstract: A feed assembly (26) for an antenna system (38) includes a first feed element (30) that propagates a first beam (32) and a second feed element (34) that propagates a second beam (36). The second feed element (34) is collocated with, but displaced vertically from, the first feed element (30) to achieve angular diversity in elevation. Each of the feed elements (30, 34) has an elongated conical shape and is formed from a dielectric material. The feed assembly (26) operates within the Ku-band frequency range to yield high gain, collimated, independent first and second beams (32, 36). The feed assembly (26) can be implemented in a tropospheric scatter communication system (38) in conjunction with a reflector (22) to provide concurrent transmit and receive capability via the two independent, angularly separated first and second beams (32, 36).

Abstract: Systems and methods for increasing bandwidth capability of an envelope elimination and restoration (EER) transmitter. A frequency response of a power supply modulator of the transmitter is approximated. An inverse response is applied to the envelope signal prior to digital-to-analog conversion (DAC) and before the signal reaches the power supply modulator to pre-emphasize the signal thereby counteracting distorting affects of the modulator. The filter is implemented using any of a variety of different digital techniques including programmable logic, DSP, etc.

Abstract: In a first aspect, an apparatus may include a first node and a second node. The first node may be configured to transmit packets of data to the second node. A first processor may be associated with the first node and a second processor may be associated with a second node. The second processor may be configured to calculate a severity level. The severity level may then be transmitted to the first node so that the first processor can determined a call admission policy (CAC/SM) policy to regulate the transmission of packets of data from the first node to the second node. In one embodiment, the number of severity levels associated with a particular network configuration may vary according to sensitivity.

Abstract: A user equipment (UE) device and associated operating techniques can be utilized to manage the queuing of network service requests in a distributed manner throughout a data communication system. The request queuing methodology leverages request queues maintained at UE devices within the system. An embodiment of a UE device that supports such request queuing includes a processor and a request queue coupled to the processor. The request queue is configured to queue one or more requests for network resources as instructed by the processor, resulting in one or more held requests. The UE device also includes a receiver element coupled to the processor. The receiver element is configured to receive a notification from the network communication component, where, in response to receiving the notification, the processor prepares the one or more held requests for transmission to the network communication component at different times.

Abstract: A communications system (20) includes a resource controller (22) and a terminal (24) in communication with the resource controller (22). Periodically, the resource controller (22) sends a service announcement (46) that identifies a set (50) of timeslots (52) within a communication resource (40) configured for random access within a future frame (42). The terminal (24) ascertains a burst characteristic (118) of a message (54) to be sent from the terminal (24) and generates a random access parameter (128). The terminal (24) selects one of the timeslots (52) from the set (50) in accordance with the random access parameter (128), the timeslot exhibiting a burst type (62) corresponding to the burst characteristic (118) of the message (54). The terminal (24) transmits the message (54) in the selected timeslot (52).

Abstract: Systems and methods are described for efficiently transmitting packetized data from a sender to a receiver over a communications link. A compression context is established between the sender and the receiver based upon commonalities in each of the data packets prior to transmitting the data over the communications link. The data is compressed according to the compression context to thereby create compressed data packets, and the compressed data packets are transmitted to the receiver across the communications link. By establishing compression contexts prior to transmission, the need for in-band signaling is reduced or eliminated.

Abstract: A system and method for capacity analysis in communication networks, particularly for on the move ad hoc wireless packet-switched networks, as well as wide variety of other multimedia networks. The invention seeks to use the same two attributes per link (link capacity and link utilization) as known circuit-switched based analysis tools while incorporating useful aspects of various statistical analyses, such as a Queuing Theory based analysis, among others. In one embodiment, the invention introduces four tests to be implemented per each link, with results of these four tests being used to color code link congestion states to generate the reports for a planner. These four tests may generate an improved analysis of the network utilizing the same number of variables used in simple conventional circuit switched based analysis.

Abstract: An RF receiver (12) includes a channel estimator (52). The channel estimator (52) includes a channel estimation filter (82), error signal generator (84), and normalized Least-Mean-Square (NLMS) filter-definition generator 86. The filter (82), error generator (84) and NLMS filter-definition generator (86) function together as an adaptive estimator. An error signal (90) is formed with a received signal (48). The filter (82) filters an estimated transmit signal (74) constructed from lower confidence decision data (66) and higher confidence known preamble data (30?). An adaptive filter definition (94) is formed in a feedback, loop which minimizes correlation between the estimated transmit signal (74) and the error signal (90). A convergence signal (122) is modulated in synchronism with the changes between lower and higher confidence data in the estimated transmit signal (74).

Abstract: Systems and methods for DC offset correction in analog and digital direct conversion RF receivers. A time derivate and subsequent integration of in-phase and quadrature phase signal path components is performed to effectively remove DC offset from the resultant down converted baseband signal.

Abstract: Systems and methods reliably transmit a message from a sender to a receiver via a network. A reliability module is configured to determine a probability of delivering a packet from the sender to the recipient via the network. Mode selection logic determines transmission mode from a number of options based upon the probability of delivering the packet from the sender to the recipient. A formatting module is configured to provide a first push that includes the message and, in at least one of the operating modes, a number of redundancy packets formulated as a function of the contents of the message. The receiver acknowledges the packets received so that any dropped packets can be re-transmitted. The redundancy packets can be created using Reed-Solomon or other forward error-correcting codes to further increase the reliability of the message transmission when network conditions warrant.

Abstract: An embodiment for wirelessly communicating a signal includes a transmitter generating and transmitting a wireless signal over a wireless communication channel. The wireless signal includes a guard band, data represented within a plurality of data-bearing subcarriers, and a plurality of pilot signals represented within a plurality of pilot subcarriers. In an embodiment, the plurality of pilot signals have variable pilot signal parameters selected from a group of parameters that includes pilot power and pilot spacing with respect to adjacent pilots. An embodiment further includes a receiver receiving a channel-affected version of the wireless signal, and producing a corrected signal by applying corrections to the received signal based on estimated channel perturbations within the received signal, where the estimated channel perturbations are determined based on the plurality of pilot signals. The receiver also produces an output data symbol from the corrected signal.

Abstract: A system and method for capacity analysis in communication networks, particularly for on the move ad hoc wireless packet-switched networks, as well as wide variety of other multimedia networks is disclosed. The invention seeks to use the same two attributes per link (link capacity and link utilization) as known circuit-switched based analysis tools while incorporating useful aspects of various statistical analyses, such as a Queuing Theory based analysis, among others. In one embodiment, the invention introduces four tests to be implemented per each link, with results of these four tests being used to color code link congestion states to generate the reports for a planner. These four tests may generate an improved analysis of the network utilizing the same number of variables used in simple conventional circuit switched based analysis.

Abstract: An embodiment for wirelessly communicating a signal includes a transmitter combining a plurality of phase shifted input data signals with a plurality of synchronization/pilot sequences to produce a plurality of combined signals, performing frequency domain-to-time domain transformations of the combined signals to produce a plurality of candidate signals, determining peak-to-average ratios for at least some of the plurality of candidate signals, identifying a selected signal from the plurality of candidate signals based on the peak-to-average ratios, and transmitting the selected signal over a wireless communication channel.

Abstract: An embodiment includes a method for generating a set of synchronization/pilot sequences (SPS) by generating a plurality of candidate SPS using different initial conditions. Correlations are performed among the candidate SPS to generate a plurality of correlation values, and a plurality of permutations of the candidate SPS are determined, where each permutation includes a different set of candidate SPS, and wherein each permutation includes a number, D, of candidate SPS. In addition a selected permutation is identified from the plurality of permutations, where the selected permutation corresponds to the set of SPS being generated. A system includes a transmitter adapted to generate a wireless signal in which an SPS is embedded by combining each SPS of the set with phase shifted input data, determining peak-to-average power ratios (PARs) for at least some of the combined signals, and identifying a selected combined signal based on the PARs.