320 results about "Antenna calibration" patented technology

A phased array antenna system includes an RF front end, a radome, and an optical calibrator embedded in the radome for enabling in-situ calibration of the RF front end. The optical calibrator employs an optical timing signal generator (OTSG), a Variable Optical Amplitude and Delay Generator array (VOADGA) for receiving the modulated optical output signal and generating a plurality of VOADGA timing signals, and an optical timing signal distributor (OTSD). The in-situ optical calibrator allows for reduced calibration time and makes it feasible to perform calibration whenever necessary.

The present invention relates to the problem of calibrating an antenna system (23) comprising an electrically controlled antenna (25) using a test antenna (45) arranged near the electrically controlled antenna, with the possibility of calibrating during operation, when disturbing reflections or other unknown signal influences are present when signals are transmitted between the test antenna and the electrically controlled antenna or between the electrically controlled antenna and the test antenna. The electrically controlled antenna comprises a number of modules (27-(1-N)) having means (91-(1-N)) for controlling the complex amplification of the modules. Each module is arranged with a commandable reference mode at reception and/or transmission. The antenna system is calibrated for reception and transmission, respectively, by transmitting test signals between the test antenna and the electrically controlled antenna and/or by transmitting test signals between the electrically controlled antenna and the test antenna, the effect of the unknown signal influence being eliminated by utilization of the reference modes at reception and/or transmission.

A wireless communication apparatus compensates for phase and amplitude imbalances existing among transmit and receive branches, while also preventing likelihood information and SNR estimation error produced by such imbalance compensation. In an apparatus having a plurality of transmit and receive antennas and respective branches for each antenna, a calibration processor multiplies receive signals in each receive branch by antenna calibration coefficients, in order to correct phase and amplitude imbalances existing among the receive branches. A transmit beamforming matrix estimator then estimates a transmit beamforming matrix by using the multiplied receive signals. An estimator then solves for estimated values such as the noise power, likelihood information, and channel waveform equalization values for each receive branch, and in addition, derives a final estimated value that takes the multiplication by correction coefficients into account when averaging the estimated values for each receive branch or when computing a weighted average according to likelihood.

The present invention relates to a method for antenna calibration in a communication system having a bandwidth divided into multiple frequency intervals M with multiple communication units 40; 50, each comprising communication circuitry 21, 24: 31, 34; 41, 42; 51, 52, 54 connected to an antenna arrangement 22, 25; 32, 35; 44, 45; 55, 49, communicating with each other over multiple communication channels. The method comprises: establishing a calibration sequence to perform antenna calibration for at least one of said multiple frequency intervals; converting the calibration sequence from the frequency domain to the time domain; transmitting a part of said calibration sequence in the time domain from a first communication circuitry 21; 34; 41; 51, 54 to a second communication circuitry 24; 31; 42; 52, 54 over the multiple communication channels; receiving the part of said calibration sequence in the second communication circuitry 24; 31; 42; 52, 54 for each communication channel; performing antenna calibration based on the received part of the calibration sequence.

The invention relates to antenna array calibration method and device in an Orthogonal Frequency Division Multiplexing (OFDM) system. The method disclosed by the invention comprises a pre-calibration step and a periodical calibration step to antennas, wherein the pre-calibration step is mainly used for acquiring compensation coefficients in a transmission direction and a reception direction of antenna units with respect to an antenna calibration unit; and the periodical calibration step performs transmission calibration and reception calibration to each antenna unit in quasi real-time according to a preset period. The method and the device disclosed by the invention can realize real-time and high-precision calibration of consistency of phases of a reception channel and a transmission channel of a Long Term Evolution (LTE) system, through common compensation to time delay and the phases through a Building Baseband Unit (BBU) and a Radio Remote Unit (RRU), can guarantee high consistency of phases of an air interface sending signal and a BBU reception signal of an antenna array, and is particularly suitable for a communication system which has high demand on consistency of antennas, for example, a Time Division Duplex (TDD)-LTE, etc..

The present invention discloses a method and device for self-calibrating an antenna in a base station of a CoMP-based TDD system, where firstly the relative reciprocity {tilde over (w)}_i of each pair of base station transmitter and receiver of the present base station relative to a calibration transmitter and receiver is calculated, and the relative reciprocity w_i of each pair of base station transmitter and receiver of the present base station relative to a reference base station transmitter and receiver is calculated by selecting one pair of base station transmitter and receiver as the reference base station transmitter and receiver, wherein i=1, 2, . . . , N; then a measurement signal is transmitted from the calibration transmitter of the present base station to the calibration receiver, and a channel response h_c,k of the calibration transmitter and receiver of the present base station is measured, wherein h_c,k=h_ct,kh_cr,k, and k=1, 2, . . . , M; _{then a channel} response h_cr,k of the calibration receiver of the present base station is measured; next the absolute reciprocity w_c,k of the calibration transmitter and receiver of the present base station is calculated in the formula of

and finally a global relative calibration weight ŵ_i of each pair of base station transmitter and receiver of the present base station from an acquired global reference w_m is calculated in the formula of

The technical solution of the invention can perform antenna calibration of a CoMP-based TDD radio communication system.

The apparatus comprises a calibration signal supply means, which supplies calibration signals to a plurality of antenna elements that are to be subjected to calibration; a calibration signal extracting means, which extracts the calibration signals from signals received by the antenna elements placed, one on each side of the plurality of antenna elements that are to be subjected to calibration, and a calibration control means and which individually controls the phases of signals to be transmitted from the plurality of antenna elements that are to be subjected to calibration, based on the phase differences among the calibration signals extracted by the calibration signal extracting means. This will realize accurate calibration of an array antenna, irrespective of antenna element interval deviation.

The invention provides a calibration method of an array antenna receiving system of a navigation satellite. The objective of the invention is to provide the calibration method which is capable of restraining interference and improving estimation accuracy of guidance vectors of the antenna array. The calibration method comprises steps of during channel calibration, sending multi-channel data output by multiple paths of analog-digital converters into a channel calibration processing module for channel calibration signal processing, measuring inconsistency between channels, successively selecting at least two channels from the channels, keeping the other channels to be normally operated, updating channel consistency response along with the time change, calculating to obtain channel responses used by an array processing algorithm module, and finishing the channel calibration; and during antenna calibration, by taking satellite signals as measurement signals, multiple paths of antenna calibration signals are synthesized through an array signal weighting processing module DBF and then sent to a navigation satellite digital receiver, outputting the antenna calibration signals to an antenna calibration processing module, calculating antenna responses of the array in the incidence direction of the satellite signals and finishing the antenna calibration.

The invention discloses a method for calibrating an antenna of a distributed base station. The method mainly comprises the following steps that: when a remote radio-frequency unit (RRU) and a base band unit (BBU) are determined to be capable of calibrating the antenna, the BBU indicates starting of calibration and sends a calibration sequence to the RRU; the RRU receives the calibration sequence and returns the received calibration sequence to the BBU; and the BBU obtains a calibration result by using a calibration algorithm according to the calibration sequence which is returned by the RRU. Moreover, the invention also discloses a system for calibrating the antenna of the distributed base station. An antenna calibration flow is realized by interaction of the BBU and the RRU, so the antenna of a frequency domain of an orthogonal frequency division multiplexing (OFDM) system can be calibrated. By adoption of the method, the amplitude and phase difference of sub-carriers or sub-carrier groups in the OFDM system can be effectively compensated, and better performance is provided for realizing of a wave beam forming function of the OFDM system.

Disclosed are a method and device for calibrating an antenna. By applying a technical solution of embodiments of the present invention, a calibration pilot frequency is transmitted by a base station to a terminal device to allow the terminal device to perform, on the basis of the calibration pilot frequency, channel measurement and information feedback for calibrating the antenna. Through such processing, the terminal device is allowed to calibrate the antenna in coordination with the base station on the basis of a pilot frequency signal meeting a requirement of a multiple antenna scenario, and, under the premise of uplink-downlink reciprocity not being established strictly, is allowed to accurately calibrate the antenna.

The embodiment of the invention discloses an antenna transmission calibration method, which comprises that: a baseband signal processor transmits a calibration sequence by a transmission radio frequency channel, and a calibration signal processor receives the calibration sequence by a calibration channel; the calibration signal processor judges whether errors of coupling networks are required to be compensated or not according to the accuracy of a receiving coupling network, calculates a calibration coefficient by the received calibration sequence, and transmits the calculated calibration coefficient to the baseband signal processor; and the baseband signal processor performs coefficient compensation according to the calibration coefficient. The embodiment of the invention also discloses an antenna transmission calibration device, which comprises the baseband signal processor, the calibration signal processor, a coupling signal processor and a coupling data memory. The embodiment of the invention can take the errors among channels of the coupling networks into account in calibration, perform the error compensation on the coupling networks, and effectively improve the antenna calibration accuracy, thereby improving beamforming performance.

An array antenna calibration apparatus simple in configuration and inexpensive while ensuring an accurate calibration of an array antenna is provided. This array antenna calibration apparatus includes supply means supplying original calibration signals to a plurality of antenna elements constituting an array antenna, the original calibration signals being orthogonal to one another among the antenna elements; a phase and amplitude characteristic calculation means calculating correlations between calibration signals, which are emitted from the antenna elements and received by the adjacent antenna elements, and the original calibration signals related to the received calibration signals; a relative calibration factor calculation means obtaining a relative calibration factor among all the antenna elements constituting the array antenna based on phase and amplitude characteristics of the respective antenna elements; and calibration means calibrating transmission signals to be supplied to the respective antenna elements based on the relative calibration factor.

The invention discloses an intelligent calibration method of an antenna transmitting channel and an antenna receiving channel and a relevant device, which is used for solving the problem that signals transmitted in an LTE (Long Term Evolution) system can not be calibrated accurately by the traditional antenna calibration technology. The method comprises the following steps of: determining frequency domain calibration factors corresponding to subcarriers loading signals to be sent, exchanging the time domain estimation value of each transmitting channel, which is isolated from the time domain signal received by the calibration channel, to obtain the frequency domain estimation value of each subcarrier of each transmitting channel by the frequency domain calibration factors, and determiningthe frequency domain calibration factors corresponding to the subcarriers according to the frequency domain estimation value of each subcarrier; and when sending signals, calibrating the signals to be sent according to the determined frequency domain calibration factors corresponding to the subcarriers.

The invention discloses an electric-adjusting antenna communication system and a method. The system comprises a base station side control unit and an electric-adjusting antenna remote control unit which are connected by a radio frequency cable. The base station side control unit is used for combining a direct current power supply signal, an antenna calibration radio frequency signal and a demodulated electric-adjusting antenna control signal into a first combining radio frequency signal, and sends the first combing radio frequency signal to the electric-adjusting antenna remote control unit through the radio frequency cable. Compared with the system and the traditional method, the invention overcomes the defects of multiple transmission signals, complicated connection, low reliability andthe like between equipment at the base station side and equipment at the antenna side, realizes the decrease of difficulty, development cost, engineering installation complexity and the like at different degrees in design, and enhances the efficiency of the electric-adjusting antenna communication.

The invention discloses a shortwave transmitting antenna three-dimensional directional diagram aerial mobile measurement system and method. The system comprises a field intensity measurement system which is composed of a loop antenna and a field intensity instrument host and an unmanned aerial vehicle platform and other parts. Computation is performed by a field intensity signal preprocessing module, a standard directional diagram computing submodule, a spatial spectrum processing submodule, a digital beam forming submodule and a transmitting antenna calibration factor computing submodule. The omnidirectional loop antenna is mainly adopted to measure field intensity signals, acquire and store the field intensity signals and preprocess the field intensity signals, then the signals are further processed through the spatial spectrum estimation technology, and finally testing is performed on the unmanned aerial vehicle platform. The index is provided for assessment of a shortwave transmitting antenna directional diagram, and online automatic monitoring of the antenna directional diagram can be realized without influencing the real-time performance and the effectiveness of the shortwave transmitting antenna so that the system and the method have the characteristics of being simple in equipment and convenient to operate.

The invention provides antenna emission calibration system and method, antenna receiving calibration system and method, and an antenna calibration system, wherein the antenna calibration system comprises a predistortion module, one or more operation emission channels, a calibration receiving channel, a calibration emission channel and one ore more operation receiving channels, wherein the predistortion module is used for carrying out digital predistortion processing on an emission calibration sequence; the one or more operation emission channel are respectively used for processing the predistorted emission calibration sequence and transmitting the processed and predistorted emission calibration sequence to a coupling network, wherein the operation emitting channel comprises a power amplification part; the calibration receiving channel is used for receiving an emission calibration sequence from the coupling network; and the one or more operation receiving channels are respectively used for receiving a receiving calibration sequence from the coupling network. The invention ensures that DPD (Digital Pre-Distortion) and AC (Antenna Calibration) cooperatively work and eliminates the nonlinearity caused by power amplification, thereby not influencing the amplitude and the phase position of the calibration sequence, ensuring that the antenna calibration is more accurate and greatly saving hardware resources by adopting a sharing mode of an operation antenna and a calibration antenna.

The invention discloses active antenna associated equipment, a system and a transmitting and receiving calibration method. Extensible design of an antenna array is achieved, construction implementation difficulty is reduced, and meanwhile construction implementation reliability is provided. The active antenna equipment comprises N active antenna arrays, a main calibration coupling circuit unit, a transmitting and receiving calibration unit, a calibration parameter storage unit and a radio over fiber (ROF) photoelectricity conversion unit, wherein the N is larger than 1. Each active antenna array at least comprises an antenna coupling circuit unit and M antenna oscillators connected to the antenna coupling circuit unit, wherein the M is larger than 1. Antenna calibration coupling circuit units of the active antenna arrays are connected to the main calibration coupling circuit unit through a calibration channel. The main calibration coupling circuit is connected with the transmitting and receiving calibration unit. The transmitting and receiving calibration unit and the calibration parameter storage unit are respectively connected to the ROF photoelectricity conversion unit.

Systems and methods for providing antenna calibration can be used in a variety of applications. A method of calibrating an antenna array for use in a traffic advisory system or traffic alert and collision avoidance system provide a mechanism that renders complex combining circuitry unnecessary in the array. A method can include receiving an unsolicited reply that contains absolute position information of an intruder aircraft. The method can also include determining a bearing of a signal encoding the reply based on a phase relationship of the signals from an antenna array not configured to operate with an internal self-test phase calibration mechanism. The method can further include comparing the bearing based on the phase relationship with a bearing calculated by a comparison of the absolute positions of a host aircraft and the intruder aircraft. The method can additionally include calibrating the antenna array based on the result of the comparison.

Embodiments of the present invention propose a method for channel state information feedback, including the following steps: a user equipment UE receives information sent by a base station, the information includes frequency band subset information for channel measurement; The channel corresponding to the frequency band subset is measured, and according to the channel measurement report mode configuration, the measurement information is sent to the base station through the physical uplink shared channel PUSCH. On the other hand, the embodiments of the present invention also propose a user equipment UE. The above solution proposed by the present invention solves the problem that the long-term/broadband PMI in the existing two-level feedback scheme can only feed back one wideband PMI for each CC, which will lead to loss of precoding performance in the case of large antenna calibration errors The problem.

A wireless communication apparatus includes a loopback transfer function acquisition section that, when a first path including all paths from each branch of the first set to each branch of the second set via the antenna is formed, acquires a loopback transfer function of each path included in the first path based on a reception status of a reference signal transmitted from each branch of the first set and received by each branch of the second set, and when a second path opposite to the first path is formed, acquires a loopback transfer function of each path included in the second path based on a reception status of a reference signal transmitted from each branch of the second set and received by each branch of the first set, and a calibration factor calculation section to calculate a calibration factor of each branch based on the acquired loopback transfer functions.

The invention provides a base station testing system and a base station testing method. The base station testing system comprises a first power divider, a second power divider, a third power divider and a band elimination filter; the first power divider is used for dividing antenna calibration port signals sent by a base station to be tested into two paths and respectively sending the two paths of the antenna calibration port signals to a coupling disc and a switching matrix to carry out antenna calibration testing; the second power divider is used for generating one or a plurality of interference signals from a plurality of signal sources according to a control command of a base station console and simultaneously sending the interference signals to the base station to be tested by a circulator and the switching matrix so as to carry out blockage and/or intermodulation testing together with a radio frequency signal transmitted by the system; and the third power divider is used for receiving the radio frequency signal sent by the switching matrix by the band elimination filter and carrying out coexistence and co-location testing on the received radio frequency signal together with the band elimination filter. By the adoption of the base station testing system and method provided by the invention, all indexes required by the standard can be tested on one platform.

A calibration apparatus for smart antenna and a method thereof are disclosed. The calibration apparatus in a receiving mode of an array antenna system includes: an additional antenna for receiving a calibration signal, which is used for calibration, from one of transmitting antennas; a frequency converter for converting a frequency of the calibration signal received from the additional antenna and generating a frequency-converted signal; a plurality of receiving frequency-converted signal from the frequency converter and outputting the frequency-converted signal; a plurality of receiving modules for converting the frequency-converted signal from the receiving antenna to have characteristics for the array antenna system; a transmitting module for generating the calibration signal and providing the calibration signal to the transmitting antenna; a calibration unit for controlling each of the receiving antennas, the receiving modules, the transmitting antenna and the transmitting modules to have the same phase characteristics based on signals received from the receiving modules; and a plurality of switches for switching a connection between the frequency converter and the receiving antennas.