Abstract: A system and method for managing and controlling a transmit power of a transmitter of a RF transmission system are disclosed. When the transmitter operates from a constrained supply like a generator or battery, power draw may limit the output that can be supported by the transmitter or result in a shutdown of the entire system. The system includes a plurality of detection and measurement circuitries to detect parameters relative to the transmitter load quality, transmitter temperatures, input waveform quality, and input power source to ensure an output power of the transmitter to stay below an allowed input power. The system and method provide a reliable transmitter that is not subject to power overloads and shutdowns caused by a circuit malfunction.

Abstract: In a system for establishing connectivity in a HF ALE cellular network, stations are organized to sound each channel, synchronized to every other station in the network. All stations make identical sounding transmissions using a single address, synchronized such that the differential timing within the coverage area remains within the mobile radios' delay spread capability. Synchronized soundings allow the mobile radio to consistently connect to the best available channel. The stations may be synchronized via a central control function. Alternatively, the stations may perform soundings based on a predetermined schedule. Where the propagation time to the mobile radio is known, or determinable within some threshold, the stations may apply a delay to the sounding transmissions to ensure that the sounding transmissions from each of the stations reaches the mobile radio at the same time within some acceptable margin.

Abstract: A radio system receives a forward error correction encoded signal for retransmission. The system performs symbol detection to produce soft decisions for the encoded bits. The soft decisions are used in the generation of the rebroadcast signal prior to any deinterleaver or error correction decoding, and the rebroadcast signal is transmitted. The system may determine if soft decisions exceed some threshold of confidence; if so, the detected bits may be used in the generation of the rebroadcast signal instead of the soft decision bit values. The system may enter a low latency mode based on some criteria such as a type of application, or a minimum necessary latency.

Abstract: An Automatic Link Establishment (ALE) system incorporating Avalanche Relay (AR) is disclosed. The system includes a plurality of network nodes such as a calling node, one or more intermediate nodes, and a responding node. The calling node transmits a link establishment message to the responding node through one or more intermediate nodes. The message is transmitted via one or more transmitting and receiving channels. The one or more intermediate nodes relay the message to the responding node or one or more different intermediate nodes. The responding node receives the message and responds back to the calling node through the one or more intermediate nodes. The message may be transmitted via the same one or more channels used to receive the message.

Abstract: A system and method for increasing the efficiency of an avalanche relay scheme is disclosed. The system and method include a plurality of networked nodes communicating in a slot and subslot scheme, with transmissions of a first signal from a first subslot relayed in subsequent subslots. The method and system include transmitting an initial transmission that includes the first signal, and then continuing to transmit at least one of a retransmitted portion of the first signal, or a transmission of an algorithmically related signal based on the first signal. The receiving node combines the first signal with the retransmitted portion of the first signal or the algorithmically related signal to determine if the initial transmission is valid. Upon a determination that the initial transmission is valid, the relay node retransmits the initial transmission in a future subslot.

Abstract: A notification system for sending a message to a receiving station via one or more repeater stations is disclosed. The repeater stations receive the message over a channel from a sending station. The distributed network immediately begins transmitting a signal coordinated with the message received where the message appears as multipath to a receiver or set of receivers. This asynchronous relay transmission start minimizes the time to incorporate additional transmitters and allows strong links to be discovered and employed without waiting for synchronized subslot transmission starts. In other operations, an asynchronous scanning operation may be included to provide a sufficient transmission time to account for network worst case net cycle times.

Abstract: In a system for establishing connectivity in a HF ALE cellular network, stations are organized to sound each channel, synchronized to every other station in the network. All stations make identical sounding transmissions using a single address, synchronized such that the differential timing within the coverage area remains within the mobile radios' delay spread capability. Synchronized soundings allow the mobile radio to consistently connect to the best available channel. The stations may be synchronized via a central control function. Alternatively, the stations may perform soundings based on a predetermined schedule. Where the propagation time to the mobile radio is known, or determinable within some threshold, the stations may apply a delay to the sounding transmissions to ensure that the sounding transmissions from each of the stations reaches the mobile radio at the same time within some acceptable margin.

Abstract: A system and method for increasing the efficiency of an avalanche relay scheme is disclosed. The system and method include a plurality of networked nodes communicating in a slot and subslot scheme, with transmissions of a first signal from a first subslot relayed in subsequent subslots. The method and system include transmitting an initial transmission that includes the first signal, and then continuing to transmit at least one of a retransmitted portion of the first signal, or a transmission of an algorithmically related signal based on the first signal. The receiving node combines the first signal with the retransmitted portion of the first signal or the algorithmically related signal to determine if the initial transmission is valid. Upon a determination that the initial transmission is valid, the relay node retransmits the initial transmission in a future subslot.

Abstract: A system for receiving multipath signals is disclosed. The system includes an equalizer that includes an input for a received data signal, wherein the received data comprises a first multipath component and a second multipath component. The equalizer further includes a channel impulse response estimator coupled to the input configured to determine one or more channel impulse response (CIR) estimates for the first multipath component and the second multipath component. The equalizer further includes a statistical estimation module coupled to the channel impulse response estimator configured to estimate a state of the first multipath component and the second multipath component based on the one or more channel impulse response estimates. The equalizer further includes a detector coupled to the statistical estimation module configured to detect data from the received data signal based on an estimated future state of the first multipath component and the second multipath component.

Abstract: A method of routing a first signal in a telecommunication network is disclosed. The telecommunication network comprises plural nodes and uses time-division multiple access (TDMA) frames, with each TDMA frame divided into time slots and each time slot is divided into subslots. The method includes the step of transmitting a first signal from an initiating node in a first subslot. The method further includes the step of receiving the first signal at other nodes in the network in the first subslot, wherein the first signal is retransmitted in a second subslot subsequent to the first subslot. An improvement in the method includes the step of preparing for the retransmission at least one of a time-dispersed first signal or time-dispersed algorithmically related first signal by two or more nodes via a controller.

Abstract: Optimal GMSK training sequences are generated by applying a base sequence to the in-phase component of the even samples and rotating the base sequence by 2k-1 and applying the second sequence to the quadrature component of the odd samples. Using the optimal GMSK training sequence a channel estimate can be generated. Filtering the channel estimate converts the channel impulse response to one that can be used with a non-GMSK signal e.g. PSK or QAM.

Abstract: A communication system is disclosed. The communication system includes a plurality of antennas disposed on one or more platforms, at least one transmitter, at least one receiver, and a control module communicatively coupled to the at least one receiver and at least one transmitter, and disposed on a separate platform than at least one antenna of the plurality of antennas. The control module is configured to control received and transmitted signals. The control module includes a controller, one or more processors, and a memory communicatively coupled to the one or more processors and having instructions stored upon. The instructions, when executed by the one or more processors, cause the one or more processors to receive antenna attribute data, and instruct the controller to configure the communication system for at least one of the diversity signal processing, the adaptive antenna processing, or the relay communication processing.

Abstract: A communication system is disclosed. The communication system includes a plurality of antennas disposed on one or more platforms, at least one transmitter, at least one receiver, and a control module communicatively coupled to the at least one receiver and at least one transmitter, and disposed on a separate platform than at least one antenna of the plurality of antennas. The control module is configured to control received and transmitted signals. The control module includes a controller, one or more processors, and a memory communicatively coupled to the one or more processors and having instructions stored upon. The instructions, when executed by the one or more processors, cause the one or more processors to receive antenna attribute data, and instruct the controller to configure the communication system for at least one of the diversity signal processing, the adaptive antenna processing, or the relay communication processing.

Abstract: A system and method for including multiple data rate sub-blocks within a single data block includes dividing data blocks based on a priority or intended set of recipients. The sub-blocks are modulated at increasing data rates and the modulated sub-blocks are appended together and bounded by the known symbol blocks during transmission. The sub-blocks are organized in order of increasing data rate. During decoding, detected symbols of a first, low data rate sub-block are included in the detection process of higher data rate sub-blocks in place of additional symbols that would otherwise be needed for higher data rate transmissions. Alternatively, the sub-blocks may be organized with low data rate sub-block at the periphery and higher data rate sub-blocks in the interior such that the data block may be decoded from both ends.

Abstract: A radio receiver system configured to remove click noise from a demodulated signal is disclosed. The radio receiver system may employ digital demodulation or analog demodulation. The radio receiver system may be configured to determine measures of a statistical distribution of amplitudes of the demodulated signal, and thresholds for limiting the demodulated signal based on the measures of the statistical distribution of amplitudes. Portions of the demodulated signal exceeding the thresholds are either soft limited or hard limited.

Abstract: A system and method for time division multiplexing voice and situational awareness data with defined transmission and retransmission windows comprises coordinating the voice and situational awareness windows at defined times across all nodes. Control signal windows and control signal retransmission windows are also defined to propagate control signals to coordinate the various voice and situational awareness windows. Voice data is prioritized for bandwidth.

Abstract: A method of routing a first signal in a telecommunication network is disclosed. The telecommunication network comprises plural nodes and uses time-division multiple access (TDMA) frames, with each TDMA frame divided into time slots and each time slot is divided into subslots. The method includes the step of transmitting a first signal from an initiating node in a first subslot. The method further includes the step of receiving the first signal at other nodes in the network in the first subslot, wherein the first signal is retransmitted in a second subslot subsequent to the first subslot. An improvement in the method includes the step of preparing for the retransmission at least one of a time-dispersed first signal or time-dispersed algorithmically related first signal by two or more nodes via a controller.

Abstract: A system and method for including multiple data rate sub-blocks within a single data block includes dividing data blocks based on a priority or intended set of recipients. The sub-blocks are modulated at increasing data rates and the modulated sub-blocks are appended together and bounded by the known symbol blocks during transmission. The sub-blocks are organized in order of increasing data rate. During decoding, detected symbols of a first, low data rate sub-block are included in the detection process of higher data rate sub-blocks in place of additional symbols that would otherwise be needed for higher data rate transmissions. Alternatively, the sub-blocks may be organized with low data rate sub-block at the periphery and higher data rate sub-blocks in the interior such that the data block may be decoded from both ends.

Abstract: A block decision feedback equalizer uses a Cholesky algorithm to factor a channel impulse response correlation matrix in order to solve for data received over a dispersive communications channel. While the Cholesky algorithm increases the computational complexity of the initial data symbol estimate (the result of a linear block estimation), its use allows the employment of a recursive update for computing successive data symbols with little additional computation. Further, the Cholesky algorithm is free of limitations that would restrict detection to cases where the channel span or memory is smaller than the probe segment following the data block to be detected. Additional functions such as diversity combining, incorporation of a time-varying channel response model and fractional baud-period sampling are provided in the block detector.