A method includes transmitting a digital code from a transmitter to a receiver. Information is transmitted via electromagnetic waves from the transmitter to the receiver. The transmission of the information includes transmitting a first portion of the information using electromagnetic waves with a first polarization in response to a first value of the digital code, and transmitting a second portion of the information using electromagnetic waves of a second polarization in response to a second value of the digital code. The first information may include a first navigational code and the second information may include a second navigational code.

A system and method for secure communications is disclosed which includes a processor(s) of a first appliqu spreading an uplink signal of a user from user equipment, where the first appliqu is coupled to the user equipment, and where the user equipment is connected to a mobile network. The processor(s) frequency shifts the spread uplink signal to maintain orthogonality over the mobile network.

A method of processing a satellite signal includes: receiving a satellite positioning system (SPS) signal, including an SPS data signal of unknown data content, from a satellite at a wireless communication device; receiving symbol indications, of determined symbol values, from a terrestrial wireless communication system at the wireless communication device; correlating the SPS data signal with a pseudo-random noise code to obtain first correlation results; and using the symbol indications and the first correlation results to determine a measurement of the SPS signal.

A method and devices are disclosed that increase the range of active geo-location from the airborne measuring station as compared with known methods by increasing the effective receive sensitivity of the airborne measuring station. In one embodiment, this may be accomplished by transmitting a burst of predetermined ranging packets and recording the correlation values of each received bit stream of the response packets with the corresponding predetermined bit streams for each of the transmitted ranging packets within a preset reception window. A rolling maximum is then performed on the correlation values in each reception window. At the end of the burst, the rolling maximum results are summed and the time of the peak value is determined.

A method and devices are disclosed that increase the range of active geo-location from the airborne measuring station as compared with known methods by increasing the effective receive sensitivity of the airborne measuring station. In one embodiment, this may be accomplished by transmitting a burst of predetermined ranging packets and recording the correlation values of each received bit stream of the response packets with the corresponding predetermined bit streams for each of the transmitted ranging packets within a preset reception window. A rolling maximum is then performed on the correlation values in each reception window. At the end of the burst, the rolling maximum results are summed and the time of the peak value is determined.

A system for calibration of a global navigation satellite system simulator, comprising a radio frequency component, a digital-to-analog conversion component, and a digital baseband component. The digital baseband component is configured to provide signals assigned to at least two sub-bands, each representing a global navigation satellite system band. The digital baseband component comprises at least one numerically controlled oscillator component that is configured to synchronize the signals assigned to the at least two sub-bands in order to provide at least two synchronized sub-bands. The digital baseband component is configured to add the signals assigned to the at least two synchronized sub-bands. Further, a method of calibrating a global navigation satellite system simulator is described.

A submersible inspection device used for inspection of, for example, liquid cooled electrical transformers can include a number of separate cameras for imaging the internal structure of the transformer. The submersible can be configured to communicate to a base station using a number of wireless transmitters and receivers. Signals transmitted to the submersible include command signals useful to effect an action on the submersible but also a heartbeat signal to indicate health of the transmitted signal. A redundant channel selection logic is provided to switch from a channel which no longer receives a heartbeat to another channel that includes a current heartbeat. Multiple signals can be received and evaluated in software, and another signal received via a firmware radio.

A method of demodulating a signal that is phase modulated to convey R chips having phase transitions between adjacent ones of the R chips to represent chip states, and an overlay symbol spanning the R chips, wherein R>1, and wherein the phase transitions are rotated in a same direction according to an overlay symbol state, comprises: first processing the signal including: accumulating a respective phase of each chip into a respective first chip magnitude, to produce R first chip magnitudes; and accumulating the R first chip magnitudes to produce a first magnitude; second processing the signal including: accumulating a respective phase of each chip into a respective second chip magnitude, to produce R second chip magnitudes; and accumulating the R second chip magnitudes to produce a second magnitude; and determining the overlay symbol state based on the first magnitude and the second magnitude.

A system for generating a frequency hopping Global Positioning System (GPS) system includes: an on-orbit reprogrammable digital waveform generator (ORDWG) configured to generate a GPS signal comprising a resilient frequency-hopping spread spectrum GPS signal that hops at a hop rate between two or more GPS channels, the GPS signal further comprising a legacy direct-sequence spread spectrum signal for at least two of the two or more GPS channels; and a receiver configured to receive the GPS signal, the radio further configured to decode the GPS signal.

A time interval measurement code-division multiple access (CDMA) transceiver including a clock manager, a transmit channel, one or more receive channels, and a processor for performing time interval measurement in two-way satellite time and frequency transfer and satellite ranging, is provided. The transmit channel generates a spread signal that is digitally phase modulated to generate and transmit the modulated intermediate frequency signal. The baseband processing of the received signal from each of the remote ground stations is performed in receive channels. A transmission time generation module generates a transmission time measurement and a reception time generation module generates a reception time measurement. The transmission time measurement and the reception time measurement are generated on a latch measurement signal that is received from a latch epoch generation module in each of the receive channels.