Abstract: A modem used for communicating data. The modem may include a packet generator and modulator. The modulator may include an electronic device configured to select at least one frequency from at least three or more candidate frequencies. At least one oscillator may be in communication with the electronic device and configured to generate respective oscillation signals in response to receiving the frequency(s) from the electronic device. A computational element may be in communication with the oscillator(s) and be configured to receive the oscillation signal(s) and produce a modulated audio signal based on the oscillation signal(s).

Abstract: A waveform acquisition system that captures and digitizes a wideband electrical signal through a bank of front end filters, frequency down converters, and conventional digitizers (A/D converters). A software algorithm reconstructs the composite input signal and applies the necessary corrections to remove the effects of hardware impairments. This approach is possible because it uses a class of filters that exhibit the quality of perfect waveform reconstruction, allowing signals whose spectral components overlap multiple filter bands, to be faithfully reconstructed. A calibration generator switched into the input port serves as a reference for quantifying and removing hardware errors. The channelized analog-to-digital converter (ADC) effectively multiplies the bandwidth and sampling rate of the conventional digitizer performance in a single channel by the number of channels in the system.

Abstract: A waveform acquisition system that captures and digitizes a wideband electrical signal through a bank of front end filters, frequency down converters, and conventional digitizers (A/D converters). A software algorithm reconstructs the composite input signal and applies the necessary corrections to remove the effects of hardware impairments. This approach is possible because it uses a class of filters that exhibit the quality of perfect waveform reconstruction, allowing signals whose spectral components overlap multiple filter bands, to be faithfully reconstructed. A calibration generator switched into the input port serves as a reference for quantifying and removing hardware errors. The channelized analog-to-digital converter (ADC) effectively multiplies the bandwidth and sampling rate of the conventional digitizer performance in a single channel by the number of channels in the system.

Abstract: A waveform acquisition system that captures and digitizes a wideband electrical signal through a bank of front end filters, frequency down converters, and conventional digitizers (A/D converters). A software algorithm reconstructs the composite input signal and applies the necessary corrections to remove the effects of hardware impairments. This approach is possible because it uses a class of filters that exhibit the quality of perfect waveform reconstruction, allowing signals whose spectral components overlap multiple filter bands, to be faithfully reconstructed. A calibration generator switched into the input port serves as a reference for quantifying and removing hardware errors. The channelized analog-to-digital converter (ADC) effectively multiplies the bandwidth and sampling rate of the conventional digitizer performance in a single channel by the number of channels in the system.

Abstract: A system that tracks and monitors a vehicle by utilizing cellular communication componentry and global positioning system componentry is disclosed. The system provides for simultaneous and continuous transmission of a voice signal and location data to a monitoring center. The monitoring center comprises componentry to communicate with the vehicle and determine the vehicle's location on a digitized map using a computer.

Abstract: A system that tracks and monitors a vehicle by utilizing cellular communication componentry and global positioning system componentry is disclosed. The system provides for simultaneous and continuous transmission of a voice signal and location data to a monitoring center. The monitoring center comprises componentry to communicate with the vehicle and determine the vehicle's location on a digitized map using a computer. In one embodiment, the location data is modulated onto a carrier and the modulated carrier is inserted into a relatively narrow band of frequencies that have been removed from an audio data channel such as, for example, a cellular telephone voice channel.

Abstract: A system which tracks and monitors a vehicle by utilizing cellular communication componentry and global positioning system componentry is disclosed. The system provides for simultaneous and continuous transmission of a voice signal and location data to a monitoring center. The monitoring center comprises componentry to communicate with the vehicle and determine the vehicle's location on a digitized map using a computer.

Abstract: An apparatus automatically determines the frequency deviation of a transmitter by analyzing a signal received from the transmitter. The apparatus automatically corrects the incoming signal for the improper deviation and maintains a record of the frequency deviation errors. Transmitters which consistently exhibit errors may then be recalled for servicing. This device increases data transmission reliability, improves compliance with FCC licensing regulations and reduces maintenance costs.