Abstract: Systems and methods for operating a system. The methods may comprise: using a machine learning model to identify which frequency of a plurality of possible frequencies that can be used by a communication device for wireless communications is an inferred best frequency based on weather report information and/or predicted weather information; performing operations to select a best frequency from the plurality of possible frequencies using the inferred best frequency and a frequency value selected by a link establishment process of the communication device; and causing the communication device to communicate signals with the best frequency which was selected.

Abstract: Systems (100) and methods (800) for communicating information. The methods comprise: storing message sets in Communication Devices (“CDs”) so as to be respectively associated with speaker information; performing operations, by a first CD, to capture an audio message spoken by an individual and to convert the audio message into a message audio file; comparing the message audio file to each reference audio file in the message sets to determine whether one of the reference audio files matches the message audio file by a certain amount; converting the audio message into a text message when a determination is made that a reference audio file does match the message audio file by a certain amount; generating a secure text message by appending the speaker information that is associated with the matching reference audio file to the text message, or by appending other information to the text message; transmitting the secure text message.

Abstract: Systems (100) and methods (800) for communicating information. The methods comprise: storing message sets in Communication Devices (“CDs”) so as to be respectively associated with speaker information; performing operations, by a first CD, to capture an audio message spoken by an individual and to convert the audio message into a message audio file; comparing the message audio file to each reference audio file in the message sets to determine whether one of the reference audio files matches the message audio file by a certain amount; converting the audio message into a text message when a determination is made that a reference audio file does match the message audio file by a certain amount; generating a secure text message by appending the speaker information that is associated with the matching reference audio file to the text message, or by appending other information to the text message; transmitting the secure text message.

Abstract: A method for compressing a short message includes receiving a short message that includes a plurality of text strings for compression, dividing the short message into one or more sub-blocks, where a number of text strings in each of the one or more sub-blocks is less than or equal to a predetermined number. The method also includes compressing each of the one or more sub-blocks by identifying a type of a first text string, identifying a code representing the type, determining whether the first text string exists in a library, upon determining that the first text string exists in the library, determining an index corresponding to the first text string, extracting a predetermined number of least significant digits of the index, and replacing the first text string in that sub-block with the code and the extracted predetermined number of least significant digits of the index.

Abstract: Determining a signal emitter location involves receiving a signal of interest (SOI) at detection devices, generating a time stamp corresponding to the arrival of the SOI at each detection device, and communicating digital data samples and the time stamp to a time-difference of arrival (TDOA) computer system. The TDOA computer system determines a TDOA of the SOI at the detection devices relative to an arrival time at a first one of the detection devices having an earliest time stamp. It determines a first solution to identify the emitter location in accordance with a first TDOA solution method. It evaluates the reliability of the first solution and selectively uses a second solution if the first solution is insufficiently reliable.

Abstract: A method for compressing a short message includes receiving a short message that includes a plurality of text strings for compression, dividing the short message into one or more sub-blocks, where a number of text strings in each of the one or more sub-blocks is less than or equal to a predetermined number. The method also includes compressing each of the one or more sub-blocks by identifying a type of a first text string, identifying a code representing the type, determining whether the first text string exists in a library, upon determining that the first text string exists in the library, determining an index corresponding to the first text string, extracting a predetermined number of least significant digits of the index, and replacing the first text string in that sub-block with the code and the extracted predetermined number of least significant digits of the index.

Abstract: A method for compressing a short message includes receiving a short message that includes a plurality of text strings for compression, dividing the short message into one or more sub-blocks, where a number of text strings in each of the one or more sub-blocks is less than or equal to a predetermined number. The method also includes compressing each of the one or more sub-blocks by identifying a type of a first text string, identifying a code representing the type, determining whether the first text string exists in a library, upon determining that the first text string exists in the library, determining an index corresponding to the first text string, extracting a predetermined number of least significant digits of the index, and replacing the first text string in that sub-block with the code and the extracted predetermined number of least significant digits of the index.

Abstract: A method for compressing a short message includes receiving a short message that includes a plurality of text strings for compression, dividing the short message into one or more sub-blocks, where a number of text strings in each of the one or more sub-blocks is less than or equal to a predetermined number. The method also includes compressing each of the one or more sub-blocks by identifying a type of a first text string, identifying a code representing the type, determining whether the first text string exists in a library, upon determining that the first text string exists in the library, determining an index corresponding to the first text string, extracting a predetermined number of least significant digits of the index, and replacing the first text string in that sub-block with the code and the extracted predetermined number of least significant digits of the index.

Abstract: Systems (400) and methods for reducing a number of cyclostationary features in a transmitted signal. The methods comprise: obtaining by a transmitter a discrete-time IF signal comprising a sequence of samples all having a same sample duration; performing operations by a sub-sample dithering processing device of the transmitter to modify a sample timing of the discrete-time IF signal by decreasing or increasing a duration of at least one first sample of the sequence using a digital signal processing technique in a digital domain; converting the discrete-time IF signal to an RF signal; and transmitting the RF signal having a reduced number of cyclo stationary features.

Abstract: Systems (400) and methods for removing dither introduced into a transmitted RF signal. The method comprising: receiving, by a receiver, the transmitted RF signal; converting, by the receiver, the transmitted RF signal into a discrete-time IF signal comprising a sequence of samples, where at least a first sample of said samples has a first sample duration different than a second sample duration of at least a second sample of said samples; and performing operations by a sub-sample dither removal device of the receiver to modify a sample timing of the discrete-time IF signal by decreasing or increasing the first sample duration of the first sample using a digital signal processing technique in a digital domain.

Abstract: Determining a signal emitter location involves receiving a signal of interest (SOI) at detection devices, generating a time stamp corresponding to the arrival of the SOI at each detection device, and communicating digital data samples and the time stamp to a time-difference of arrival (TDOA) computer system. The TDOA computer system determines a TDOA of the SOI at the detection devices relative to an arrival time at a first one of the detection devices having an earliest time stamp. It determines a first solution to identify the emitter location in accordance with a first TDOA solution method. It evaluates the reliability of the first solution and selectively uses a second solution if the first solution is insufficiently reliable.

Abstract: A communication network may be uncooperative with an uncooperative communications device. The communication network includes mobile wireless communications devices including a collection device and forward devices. Each forward device is configured to detect a received signal characteristic associated with the uncooperative communications device, and transmit the received signal characteristic to the collection device. The collection device is configured to selectively schedule reception of the received signal characteristic based upon a timing of communications among the forward devices, and determine a parameter associated with the uncooperative communications device based upon the received signal characteristic.

Abstract: An HF communication system includes a first device, and a second device. The first device sends a message to the second device, the message including a preamble portion, a variable length data portion after the preamble portion having a given ending point selected from among potential ending points, and a check portion after the variable length data portion indicating an end of the message. The second device performs a decoding operation on the message at a potential ending point, and performs a check operation on a potential check portion of the decoded message, and when the check operation is successful, recovers the variable length data portion from the decoded message. Otherwise, the second device performs another decoding operation on the message at a next potential ending point, and performs another check operation on another potential check portion of the respective decoded message.

Abstract: A mobile wireless communications device may include an antenna, and a receiver coupled to the antenna and being configured to use a modulation having memory for a received message in a block structure. The block structure may include a pair of mini-probes and a body therebetween. The receiver may be configured to demodulate the received message by determining a corresponding set of received signal characteristic values based upon the pair of mini-probes, and determining a decode starting point in the body based upon the set of received signal characteristic values. The receiver may be configured to demodulate the received message by at least, from the decode starting point, decoding the body in a first time direction, and decoding the body in a second time direction based upon a result of the decoding in the first direction.

Abstract: The communications device includes a phase and frequency tracking loop having a signal input and an adjustable loop filter that establishes a predetermined tracking loop bandwidth for samples of communication signals received at the signal input and processed within the tracking loop. A tracking loop update circuit updates loop filter operating parameters and is operative with the loop filter for increasing or decreasing the tracking loop bandwidth of the phase and frequency tracking loop based on the dynamics of the frequency offset of measured samples from the output of the loop filter over time.

Abstract: A communications system includes a first communications device cooperating with a second communications device. The first communications device multiplexes a digital speech message and a corresponding text message into a multiplexed signal, and wirelessly transmits the multiplexed signal. The second communications device wirelessly receives the multiplexed signal, de-multiplexes the multiplexed signal digital into the speech message and the corresponding text message, decodes the speech message for an audio output transducer, and operates a text processor on the corresponding text message for display. The corresponding text message is displayed in synchronization with the speech message output by the audio output transducer. A memory is coupled to the text processor for storing the text message, and the text processor is configured to display the stored text message.

Abstract: A communications device includes a phase and frequency tracking loop having a signal input and adjustable loop filter that establishes a predetermined tracking loop bandwidth for samples of communication signals received at the signal input and processed within the tracking loop. A tracking loop update circuit updates the loop filter operating parameters. It is operative with the loop filter for increasing or decreasing the tracking loop bandwidth of the phase and frequency tracking loop based on the measured signal-to-noise ratio in the received samples of communication signals at the signal output by the tracking loop and on the known or measured apriori tracking capabilities of demodulator based on the symbol rate of communication signal.

Abstract: A communication network may be uncooperative with an uncooperative communications device. The communication network includes mobile wireless communications devices including a collection device and forward devices. Each forward device is configured to detect a received signal characteristic associated with the uncooperative communications device, and transmit the received signal characteristic to the collection device. The collection device is configured to selectively schedule reception of the received signal characteristic based upon a timing of communications among the forward devices, and determine a parameter associated with the uncooperative communications device based upon the received signal characteristic.

Abstract: A wireless communications device may be configured to perform a first demodulation based upon a first sampling rate of a received signal to generate a first demodulated signal and determine therefrom whether a first error value is not greater than a first threshold, and, if so then decode the first demodulated signal. If the first error value is greater than the first threshold, a second demodulation is performed based upon a second sampling rate of the received signal greater than or equal to the first sampling rate to generate a second demodulated signal and determine therefrom whether a second error value is not greater than a second threshold, and, if so, then decode the second demodulated signal. If the second error value is greater than the second threshold, the second demodulation is performed at least one additional time with at least one change thereto.

Abstract: A communications system includes a first communications device cooperating with a second communications device. The first communications device multiplexes a digital speech message and a corresponding text message into a multiplexed signal, and wirelessly transmits the multiplexed signal. The second communications device wirelessly receives the multiplexed signal, de-multiplexes the multiplexed signal digital into the speech message and the corresponding text message, decodes the speech message for an audio output transducer, and operates a text processor on the corresponding text message for display. The corresponding text message is displayed in synchronization with the speech message output by the audio output transducer. A memory is coupled to the text processor for storing the text message, and the text processor is configured to display the stored text message.