Abstract: The present invention is related to location positioning systems, and more particularly, to a method and apparatus of synchronizing to data frames in a positioning system signal. According to one aspect, the invention speeds up the frame synchronization process by computing a frame synchronization metric for each satellite and then combining together the metrics for all tracked satellites together, after compensating for respective signal transit times. Then the invention makes a frame sync decision on the combined satellite metric. In embodiments, an optimal combining algorithm is used based on CNO of each satellite. According to further aspects, the invention further speeds up the frame synchronization process by predicting many bits in the subframe so that more bits are known in addition to the 8-bit preamble. For example, the invention recognizes that many bits in a subframe rarely change or don't change very often. Moreover, the invention uses old ephemeris used to predict new ephemeris parameters.

Abstract: Systems and methods are disclosed herein to use what is referred to as adaptive continuous tracking (ACT) to reduce the power consumption of GNSS receivers. In GNSS receivers, performance as measured by position accuracy is a function of the observation time of the satellites. A longer observation time translates into more reliable range measurements and demodulated data, and ultimately into better positioning accuracy of the receivers. However, a longer observation time also means more power consumption. ACT allows satellite observation time to be tuned to the desired positioning performance by dynamically adjusting the on time period of the receivers while maintaining a minimum performance metric. The performance metric may be formed from a combination of the estimated position error, the horizontal dilution of precision (HDOP), the data collection state, and the receiver operating environment as characterized by the carrier to noise ratio (CN0).

Abstract: A system and method capable of mitigating the migration from the current GPS system to the Galileo system and allow a single satellite system positioning receiver to process both GPS signals and Galileo signals.

Abstract: Systems and methods are disclosed herein for improving the sensitivity of satellite data decode in a satellite navigation receiver. The low signal ephemeris data decoding system of the present disclosure achieves a 5 db improvement in decoding sensitivity over conventional system by operating down to a CN0 of 21 dB-Hz. The improved sensitivity is achieved through a combination of reducing the number of data bits to be decoded, overcoming the inherent differential decoding problem of an all data bit polarity inversion, improving the probability of seeing single bit decoding error in an ephemeris word, running the parity correction algorithm, and reducing the undetected word error rate. The improved sensitivity makes it possible to predict the orbit of the satellite and to determine the receiver's location with higher accuracy even when operating in challenging signal conditions.

Abstract: A GPS Mobile Unit is described. The GPS Mobile Unit may include at least two antennas, at least two GPS receivers, and a position solution module in signal communication with the at least two GPS receivers.

Abstract: A positioning system receiver that mitigates the effect of continuous wave (CW) carrier interference with post correlation processing in a satellite positioning receiver, while not distorting the signal waveform or degrading receiver sensitivity and performing in low signal and dynamic interference environments.

Abstract: A positioning system receiver that mitigates cross correlation of received signals from positioning system satellite vehicles by generating the strong satellite vehicle signal and subtracting it from the received signal before correlation while eliminating the need for cross correlation signature without changing the C/A code.

Abstract: A positioning system receiver that mitigates narrowband interference by dynamically choosing the mitigation technique that yields the best interference mitigation capability with the least signal degradation to maximize receiver performance parameters such as receiver sensitivity, multipath resolution, and low power.

Abstract: A GPS Mobile Unit is described. The GPS Mobile Unit may include at least two antennas, at least two GPS receivers, and a position solution module in signal communication with the at least two GPS receivers.

Abstract: A method of decoding a GPS carrier signal comprising: (A) receiving a phase modulated GPS signal by using a GPS antenna; (B) extracting a GPS data from the received phase modulated GPS signal; and (C) computing a total probability of a current GPS data bit being “one” or “zero” at a GPS time epoch by using a decoding algorithm.

Abstract: This invention relates to improving the signal-to-noise ratio of semi-codeless tracking by presenting a method and apparatus which employs an optimal W-code timing pattern, and/or provides signal-to-noise gain by adding L1 and L2 W-code bit timing estimate signals before combining the L1 W-code estimate signal with the L2 W-code estimate signal.

Abstract: A satellite positioning system (SATPS) receiver has a mix of standard and enhanced digital channel processors. The standard digital channel processors perform continuous tracking. During a low SNR and/or fast acquisition mode, the enhanced digital channel processor accumulates samples of a SATPS signal that are identically positioned within corresponding PRN code repetition periods, and plays back the stored accumulated values of the samples in an integration period to a correlation section for correlation with a locally generated PRN code.

Abstract: This invention relates to improving the signal-to-noise ratio of semi-codeless tracking by presenting a method and apparatus which employs an optimal W-code timing pattern, and/or provides signal-to-noise gain by adding L1 and L2 W-code bit timing estimate signals before combining the L1 W-code estimate signal with the L2 W-code estimate signal.

Abstract: The present invention relates to the new W code enhanced GPS receiver which allows to receive and demodulate the L1 and L2 satellite signals encrypted with the unknown Y code. No assumptions are made about the timing or the structure of the unknown Y code. The signal-to noise ration is not compromised in comparison with the reception of the L1 and L2 signals without code encryption.