Abstract:
A system and method for obtaining a frequency error estimate representing the difference between a reference frequency and the frequency of a space-time transmit diversity signal is disclosed herein. The method includes taking the correlation of total sums, comprised of partial sums taken in defined first and second intervals, to represent the frequency error as the imaginary component of the correlation function.
Abstract:
Methods and apparatus for expeditiously releasing network resources for a mobile station based on low battery and lost signal conditions are disclosed. The wireless network (104) receives a power down warning message from the mobile station (102) indicative of a low battery condition. The wireless network (104) then identifies whether a lost signal condition exists with the mobile station (102). In response to receiving the power down warning message and subsequently identifying the lost signal condition, the wireless network (104) causes network resources for the mobile station to be released. The wireless network (104) infers that the mobile station (102) has powered down due to low battery without enough time to send a power down registration to the wireless network (104).
Abstract:
A method of system access from a wireless device to a wireless network, the network having a plurality of base stations includes the steps of: selecting at least one reverse link cost metric from a list of predetermined reverse link cost metrics; determining a reverse link cost according to the selected at least one reverse link cost metric; selecting a candidate base station from the plurality of base stations; sending a probe signal at the reverse link cost to the candidate base station; waiting for a response from the candidate base station within a timeout period; and repeating steps until timeout, or until the condition that a response is received from at least one candidate base station so that at least one candidate base station can be used to provide system access from the wireless device to the wireless network.
Abstract:
A system and method of controlling transmit power for mobile wireless devices with multi-mode operation of antenna are disclosed. A radio control system in a communication device is disclosed, the radio control system comprising: (a) a sensor capable of detecting a change in use mode of said device; (b) a power controller connected to said sensor to determine a power configuration based on the use mode; and (c) a power regulator connected to said power controller to apply the power configuration to a transmitted signal. A method of controlling a power configuration in a communication device is disclosed, comprising the steps of: (a) detecting a use mode; (b) changing the power configuration as a function of the use mode; and (c) communicating at the changed power configuration. A radio control system in a communication device is disclosed, comprising: (a) a sensor capable of detecting a change in use mode of said device; (b) a radio controller connected to said sensor to determine a radio configuration based on the use mode; and (c) a radio configuration module connected to said radio controller to apply the radio configuration to the transmitted signal.
Abstract:
A peak power regulator is disclosed that functions within a Code Division Multiple Access (CDMA) transmitter to reduce peak power spikes within baseband signals while maintaining the average output power consistent with the average input power, controlling the out-of-band emissions, and maintaining the in-band signal quality within an acceptable degradation. In-phase and quadrature baseband signals are input to a delay block and an envelope magnitude predictor within the peak power regulator. The envelope magnitude predictor outputs an estimate for the magnitude of the envelope that will be generated when the inputted baseband signals are modulated. This estimate is input to a multiplier that generates a ratio by dividing the estimate by a maximum acceptable envelope magnitude. The ratio is subsequently input to a mapping table that outputs a scaling factor sufficient for reducing peak power spikes. The scaling factor is subsequently input to an optional mean power regulator that generates an instantaneous gain value sufficient to maintain the average output power level at the average input power level. This gain value is applied to two multipliers that are also input with delayed versions of the in-phase and quadrature baseband input signals. The outputs from these two multipliers, after being filtered within lowpass filters to remove out-of-band emissions caused by the scaling, are output from the peak power regulator. These peak power reduced outputs have any peak power spikes scale reduced while maintaining the average power constant.
Abstract:
Doppler LIDARs, such as those used in ADAS (advanced driver assistance system) and autonomous vehicles, may need to sense objects at many directions. Some of the Doppler LIDAR devices use mechanically moving parts to scan over a range of directions and the various directions are not sensed simultaneously but sensed in turns over time. Mechanical moving parts generally have higher costs, lower reliability and shorter Mean Time To Failure (MTTF). The LIDAR sensor on chip with Doppler-sensing pixels disclosed herein uses a Doppler sensing-chip that enables Doppler LIDAR devices to sense many directions simultaneously in parallel without having to use mechanical scan and mechanical moving parts, even without having to use electronic scan. Lower costs, higher reliability, and faster detection time as well as higher direction sensing accuracy are objectives of this invention.
Abstract:
In many applications such as autonomous vehicle and ADAS (advanced driver assistance system), both LIDAR sensor and camera sensor play important and complementary roles in sensing surroundings. The scanless LIDAR sensor on chip architecture disclosed in this application is suitable to build a LIDAR and a camera sensor on a single chip and share one set of optics, enabling a combined FMCW Doppler LIDAR and camera sensor inherently to work together and jointly sense directions simultaneously in parallel without mechanical, electronic or phonic scanning, no extra efforts needed to align them either. Lower costs, higher reliability, and faster detection as well as higher direction sensing accuracy and multi-domain sensing are objectives of this invention. The combined optical sensor provides object sensing information in multiple domains: angles of view (direction vector), distance, relative velocity, colors (in Red-Green-Blue victor) and light strength.
Abstract:
Doppler LIDARs, such as those used in ADAS (advanced driver assistance system) and autonomous vehicles, may need to sense objects at many directions. Some of the Doppler LIDAR devices use mechanically moving parts to scan over a range of directions and the various directions are not sensed simultaneously but sensed in turns over time. Mechanical moving parts generally have higher costs, lower reliability and shorter Mean Time To Failure (MTTF). The LIDAR sensor on chip with Doppler-sensing pixels disclosed herein uses a Doppler sensing-chip that enables Doppler LIDAR devices to sense many directions simultaneously in parallel without having to use mechanical scan and mechanical moving parts, even without having to use electronic scan. Lower costs, higher reliability, and faster detection time as well as higher direction sensing accuracy are objectives of this invention.
Abstract:
The present invention discloses a full-polarization-state power distributor with integer ratio of power distribution based on photonic crystal waveguide which comprises a photonic crystal waveguide formed in a photonic crystal with a complete photonic band-gap, and the photonic crystal consists of background dielectric rod array; the photonic crystal waveguide consists of a transverse waveguide and a perpendicular waveguide perpendicularly connected with the transverse waveguide; one end of the transverse waveguide is an input end, and the other end is an output end; the perpendicular waveguide is another output end; and the middle part of the transverse waveguide is provided with waveguide defect dielectric rods. The structure of the present invention has a small volume, high light transmission efficiency, it is convenient for optical integration and highly efficient and it is suitable for large-scale optical integrated circuits and can realize the function of full-polarization-state power distribution with integer ratio for different wavelengths.