Abstract: A multiple-input multiple-output (MIMO) system can transmit on multiple antennas simultaneously and receive on multiple antennas simultaneously. Unfortunately, because a legacy 802.11a/g device is not able to decode multiple data streams, such a legacy device may “stomp” on a MIMO packet by transmitting before the transmission of the MIMO packet is complete. Therefore, MIMO systems and methods are provided herein to allow legacy devices to decode the length of a MIMO packet and to restrain from transmitting during that period. These MIMO systems and methods are optimized for efficient transmission of MIMO packets.

Abstract: A receiver for receiving both GPS signals and GLONASS signals is provided. This receiver includes an analog front end (AFE), a GPS digital front end (DFE) and a GLONASS DFE for receiving an output of the AFE, and a dual mode interface (DMI) for receiving outputs of the GPS and GLONASS DFEs. Search engines are provided for receiving outputs of the DMI. Notably, certain front-end components of the AFE are configured to process both the GPS signals and the GLONASS signals.

Abstract: A high sensitivity GPS receiver includes an acquisition engine and a tracking engine. The acquisition engine processes GPS satellite data at data rate that is substantially equal to twice the coarse acquisition (CA) code chip rate. This data rate advantageously enables the acquisition engine to process GPS satellite data with relatively less hardware area than traditional GPS acquisition approaches. In one embodiment, the high efficiency acquisition engine may be over-clocked, thereby allowing different phases of a CA code to be correlated quickly. The tracking engine can advantageously process GPS satellite data at a data rate that does not have an integer relationship to the CA code chip rate.

Abstract: This disclosure is directed to methods and systems for locally generating calculated ephemerides that may be used by a navigation device to calculate position information before a broadcast ephemeris from a given navigation satellite has been completely received or when the broadcast ephemeris from the satellite is not available. Generally, the invention includes the steps of calibrating the initial satellite velocity from the last available broadcast ephemeris, correcting the clock for a prediction time period, predicting the satellite position during the time period and formatting the predictions into a calculated ephemeris to be used by the receiver to determine position information.

Abstract: A high sensitivity GPS receiver includes an acquisition engine and a tracking engine. The acquisition engine processes GPS satellite data at data rate that is substantially equal to twice the coarse acquisition (CA) code chip rate. This data rate advantageously enables the acquisition engine to process GPS satellite data with relatively less hardware area than traditional GPS acquisition approaches. In one embodiment, the high efficiency acquisition engine may be over-clocked, thereby allowing different phases of a CA code to be correlated quickly. The tracking engine can advantageously process GPS satellite data at a data rate that does not have an integer relationship to the CA code chip rate.

Abstract: A receiver unit of a communication device can employ multiple correlators for decoding the access address of a packet received from another communication device. A dynamically determined primary frequency offset is applied to a phase difference signal that is determined from an RF signal that comprises the packet. For each of a plurality of access address decoding chains of the receiver unit, a secondary frequency offset associated with the access address decoding chain is applied to the phase difference signal, the phase difference signal is correlated with a predetermined access address of the communication device, and a resultant correlation output is compared against a correlation threshold. One of the access address decoding chains that generated the correlation output that is greater than the correlation threshold is selected and the packet is demodulated based, at least in part, on the phase difference signal corresponding to the selected access address decoding chain.

Abstract: A receiver for receiving both GPS signals and GLONASS signals is provided. This receiver includes an analog front end (AFE), a GPS digital front end (DFE) and a GLONASS DFE for receiving an output of the AFE, and a dual mode interface (DMI) for receiving outputs of the GPS and GLONASS DFEs. Search engines are provided for receiving outputs of the DMI. Notably, certain front-end components of the AFE are configured to process both the GPS signals and the GLONASS signals.

Abstract: A receiver for receiving both GPS signals and GLONASS signals is provided. This receiver includes an analog front end (AFE), a GPS digital front end (DFE) and a GLONASS DFE for receiving an output of the AFE, and a dual mode interface (DMI) for receiving outputs of the GPS and GLONASS DFEs. Search engines are provided for receiving outputs of the DMI. Notably, certain front-end components of the AFE are configured to process both the GPS signals and the GLONASS signals.

Abstract: A method of determining a distance between a first wireless device and a second wireless device is provided. In this method, a location symbol can be generated by filtering and modulating a pseudorandom (PRN) code. The location symbol can be provided in a data field of a legacy wireless packet to form a first location packet. The first location packet can be transmitted from the first wireless device to the second wireless device. A second location packet can be transmitted from the second wireless device to the first wireless device, wherein the second location packet is substantially identical to the first location packet. An effective roundtrip time between the first and second wireless devices can be determined based on the first and second location packets. The distance between the first and second wireless devices can be computed using this roundtrip time.

Abstract: A satellite navigation receiver receives a combination of radio frequency signals from satellites in satellite navigation systems and process the radio frequency signals to calculate an approximate current location of the satellite navigation receiver. Satellite acquisition plays an important part in identifying the current location of the satellite navigation receiver. Acquisition involves identifying the satellites in the satellite navigation that can be used to provide navigation information. Fast Fourier transform based acquisition involves using FFT and subsequently inverse FFT (IFFT) to correlate a coarse acquisition (C/A) code transmitted by a satellite with a C/A code locally generated on the GPS receiver to identify and acquire a transmitting satellite.

Abstract: A technique for reducing the dwell time in acquiring a satellite signal is provided. The technique minimizes the dwell time in searching for a satellite signal in cells of a search space by comparing the peak-power-to-average ratio (PAPR) to one or more thresholds at one or more intermediate points during the search in a code phase/Doppler frequency bin. The comparison is then used to determine whether to continue the search in a current code phase/Doppler frequency bin or to continue to the next code phase/Doppler frequency bin.

Abstract: A satellite navigation receiver having a digital front end. The satellite navigation receiver includes an analog section for receiving, amplifying, and filtering a satellite navigation signal. The digital front end is coupled to the analog section and is used to perform digital signal processing on the satellite navigation signal before it is passed on to the acquisition and tracking engines. By off-loading some of the functionality from the analog section to the digital front end, the analog section may be made smaller and cheaper and may consume less power. Moreover, additional functionalities can be added to the digital front end to improve performance. Since the digital front end is comprised of digital circuitry, it scales down in size, cost, and power with advances in semiconductor fabrication techniques.

Abstract: A mechanism for weak signal packet detection in a wireless receiver. Cross-correlation and self-correlation operations are performed on a plurality of short training field symbols associated with a plurality of RF signals received at a plurality of receiver chains of the wireless receiver. A plurality of self-correlation outputs generated in the plurality of receiver chains are summed and the sum of the self-correlation outputs is accumulated over a predetermined number of STF symbol periods. A moving sum operation is performed on the accumulation output when the accumulation output is greater than a first predetermined threshold. A signal indicating a data packet has been detected is generated when the moving sum output is greater than a second predetermined threshold.

Abstract: A high sensitivity GPS receiver includes an acquisition engine and a tracking engine. The acquisition engine processes GPS satellite data at data rate that is substantially equal to twice the coarse acquisition (CA) code chip rate. This data rate advantageously enables the acquisition engine to process GPS satellite data with relatively less hardware area than traditional GPS acquisition approaches. In one embodiment, the high efficiency acquisition engine may be over-clocked, thereby allowing different phases of a CA code to be correlated quickly. The tracking engine can advantageously process GPS satellite data at a data rate that does not have an integer relationship to the CA code chip rate.

Abstract: A device can access scaled values and scaling factors, which are used to convert the scaled values into coefficients and residuals. The coefficients and residuals can in turn be used with time-dependent functions to reconstruct predicted ephemeris data, including clock correction data, for satellite navigation system satellites. Ephemeris data that is broadcast from any of the satellites can be used to update the calculated ephemeris data.

Abstract: A high sensitivity GPS receiver includes an acquisition engine and a tracking engine. The acquisition engine processes GPS satellite data at data rate that is substantially equal to twice the coarse acquisition (CA) code chip rate. This data rate advantageously enables the acquisition engine to process GPS satellite data with relatively less hardware area than traditional GPS acquisition approaches. In one embodiment, the high efficiency acquisition engine may be over-clocked, thereby allowing different phases of a CA code to be correlated quickly. The tracking engine can advantageously processes GPS satellite data at a data rate that does not have an integer relationship to the CA code chip rate.

Abstract: Updates to an AFC loop can be performed to provide high-sensitivity tracking. A 20 ms update interval and PDI=10 ms is used for every other update. A setting is used for each update between the 20 ms updates. Notably, the setting uses PDI=5 ms. The setting can include first, second, and third cross-dot pairs associated with a first bit, a second bit, and a cross-bit boundary between the first and second bits, respectively. A sum of these pairs can be scaled down when the signal strength is below a predetermined threshold. In another embodiment, the setting can include a first cross-dot pair associated with a first bit and a second cross-dot pair associated with a second bit. A sum of these pairs can also be scaled down when signal strength is below a predetermined threshold.

Abstract: This disclosure is directed to devices and methods for providing a time synchronized WLAN system. Stationary APs in a WLAN system can determine accurate timing information from a GNSS satellite, so as to synchronize with each other. The synchronized APs can then be used to determine position information for devices on the network using pseudo-ranging techniques.

Abstract: A device can access scaled values and scaling factors, which are used to convert the scaled values into coefficients and residuals. The coefficients and residuals can in turn be used with time-dependent functions to reconstruct predicted ephemeris data, including clock correction data, for satellite navigation system satellites. Ephemeris data that is broadcast from any of the satellites can be used to update the calculated ephemeris data.

Abstract: A system and method are disclosed for transmitting data over a wireless channel. In some embodiments, transmitting data includes receiving convolutionally encoded data and enhancing the transmission of the data by further repetition encoding the data.