摘要:
A method is described that enables a system to estimate the individual times of arrival of multi-path signals components in a received signal while blind to the particular angular response characteristics of an antenna array. Additionally, a system is described that estimate the impulse response of the modulation channel. The impulse response is used to generate impulse response estimates for all multi-path signal components without reference to the actual angle of arrival of the signal. The impulse response for the multi-path constituents are directly associated with the time delays on each path, providing delay estimates for each path.
摘要:
A method for calibrating an antenna and signal processing system enabling angle of arrival (AOA) determination for a frequency hopping signal, in which a calibration coefficient is determined in response to one or more calibration signals injected into the system at one or more of the frequencies in the hopping sequence and proximate in time to reception of the communication signal. The calibration coefficients are reflective of a frequency and time dependent parameter of a path between the antenna and wireless location sensor. The AOA is determined as a function of the calibration coefficient and the radio frequency energy of the received communication signal. Several embodiment of the method are illustrated.
摘要:
An in-line surge suppressor having a body with a bore between two ends and at least one channel located within the body and around the bore. An inner conductor is located within the bore. A shorting element has a plurality of segments that extend from the inner conductor, through extension grooves between the channel and the bore, into a common or separate channel(s). The segments coupled to the channel(s), proximate a distal end of each segment.
摘要:
A system and method is disclosed that correlates the MSISDN of a target mobile by performing an out of band request using a IMSI. The correlation between the MSISDN and the IMSI of IMEI is cashed at a database for retrieval. The correlation of the MSISDN allows the position of a mobile device to be determined using a CoPL and/or SUPL location determination sessions.
摘要:
A system and method is disclosed that determines the position of a mobile device using information obtained by employing a first location determination protocol (or modality) to control the efficient or advantageous invocation of a second location determination protocol (or modality). The system utilizes information readily available from the Control plane along with request parameters and device capabilities to determine whether to invoke a CoPL or SUPL session.
摘要:
In a receiver of a transmission system in which the data transmission rate is not an integer multiple of the spacing between transmission channels, a single oscillator is used to generate both the system clock used to process the data signal as well as the mixing signal used to downconvert the received RF signal to an intermediate frequency (IF). The frequency error in the IF signal that results from mixing the RF signal at a less-than-ideal mixing frequency is compensated by selecting an appropriate mixing signal frequency applied when downconverting the IF signal to baseband. In a transmitter, the mixing signal frequency used to upconvert the outgoing baseband signal to IF is selected to pre-compensate for the frequency error resulting from upconverting the IF signal to RF using a less-than-ideal mixing frequency. In either case, the receiver/transmitter can be implemented without having to provide a dedicated reference oscillator for converting signals between RF and IF.
摘要:
A feed having a waveguide with a longitudinal axis. A plurality of corrugations extending from an end of the waveguide. The corrugations coaxial with the longitudinal axis, forming an extension of the waveguide. The corrugations having an end face angle less than 90 degrees with respect to the longitudinal axis to squint the feed beam.
摘要:
A shorting stub for connection between an inner conductor and an outer conductor of a coaxial cable. The shorting stub of a tungsten or tungsten alloy, having a connecting portion between an inner conductor connection and an outer conductor connection. The shorting stub may be cost effectively formed using metal injection molding techniques. The connecting portion may be formed by a plurality of loop segments in a range of different configurations. If needed, one or more supports may be applied to support the shorting stub during the metal injection molding.
摘要:
A non-linearity generator operates on a signal between a frequency converter and an amplifier and acts as a postdistorter for the component it follows and as a predistorter for the component it precedes, thus linearizing the overall input-output characteristic of the circuit. Cross-modulation components distorting an injected pilot signal provide a feed-back signal that is used to control the distortion applied by a non-linearity generator. The non-linearity generator can be adapted to cope with widely spaced input tones. The circuit may form part of a transmitter or a receiver.
摘要:
An active antenna array for use in a beamforming antenna system. The antenna array includes multicarrier power amplifiers coupled to each antenna element wherein the outputs of the multicarrier power amplifiers are linearized. The antenna array communicates with a base station control unit located at the base of the cellular tower in digital baseband. Fiber optic transmission lines couple the antenna arrays with the base station control unit. Multicarrier linear power amplifiers may be coupled to the antenna elements to linearize the outputs of the antenna elements. Alternatively, a predistortion circuit is coupled to the antenna elements to linearize the outputs of the antenna elements when multicarrier power amplifiers are used.