Abstract: Methods, apparatuses and systems are provided for use in a wireless routing network. One apparatus, for example, includes an adaptive antenna that is configurable to receive a transmission signal from a transmitter and in response transmit corresponding outgoing multi-beam electromagnetic signals exhibiting a plurality of selectively placed transmission peaks and transmission nulls within a far field region of a coverage area. The adaptive antenna may also be configured to selectively receive at least one incoming electromagnetic signal directed through the coverage area. The adaptive antenna includes at least one antenna array and logic. The antenna array has a plurality of antenna elements. The logic is operatively coupled to the antenna array and configured to selectively control the placement of the transmission peaks and transmission nulls within the outgoing multi-beam electromagnetic signals.

Abstract: A system and method for forming a beam and creating nulls. The inventive method combines frequency domain suppression technology for narrow-band jammer rejection with orthogonal weighting using Eigen analysis for jammer nulling and signal beam-forming for an array antenna system. The inventive system is adapted for use with an adaptive array antenna having a plurality of radiating elements. The system includes a frequency domain suppressor connected to the array antenna and an orthogonal weighting subsystem connected to the frequency domain suppressor. In the illustrative implementation, signals received by each radiating elements are processed by an analog front-end and digitized. The frequency domain suppressor includes a Fast Fourier transformer (FFT) and a frequency domain suppressor for each element in the array. The frequency domain suppressor further includes a threshold evaluator which reads the signals output by the FFT's and provides threshold controls to the spectral suppressors.

Abstract: A dipole antenna with a radiating structure comprises at least one device adapted to the conversion of analog signals into digital signals and/or digital signals into analog signals, said device being positioned in a part of the antenna that is insulated from electromagnetic waves or phenomena The antenna can be used in radiocommunications systems.

Abstract: A direction for a desired radio signal arriving at a receiving station is determined from a plurality of estimated signal medium response coefficients for a ray of the desired radio signal. According to an aspect of the present invention, the estimated signal medium response coefficients for the ray are generated according to an interference rejection combining (IRC) process. According to another aspect, a direction of arrival for a ray of the desired signal is determined and used to compute a power spectral density for the ray for a plurality of directions. A direction of arrival for the ray is then determined by determining a direction for which the power spectral density has a maximum value. In addition to desired signal direction, direction of arrival for an interfering signal can be determined using an impairment autocorrelation matrix that is also generated as part of the IRC process.

Abstract: A reference signal is modulated in a modulation circuit 101. The modulated reference signal is multiplied by a transmission weight before being performed radio transmission processing at transmission RF circuits 109 to 111. Respective reference signals are combined at a combining circuit 119. Then, the combined reference signals are compared with original reference signal at a correction value control circuit 121. On the basis thereof, respective correction values of a phase and an amplitude are obtained. A radio transmission device adjusts the phase and the amplitude of transmission signal while employing the correction values.

Abstract: A system and method of tracking ambient signals, detecting or receiving desired signals, and suppressing undesired signals. An array of sensors receives ambient signals and generates N channels of data. A transformation device accepts the data from the array and generates N′ channels of data. An adaptive processor accepts the N′ channels of data from the output of the transformation device and processes the N′ channels of data to update the settings of the transformation device, such that only N′ degrees of freedom are adaptively manipulated by the adaptive processor at an instant, the manipulation being done in a manner that instantaneously senses changes in signal environment and adjusts the settings of the transformation device in a closed-loop. The adaptive processor optionally combines these N′ channels to produce system output beam(s) that remove residual interference present out the output of the transformation device.

Abstract: There are provided adaptive beamforming algorithms for an adaptive array smart antenna. According to one embodiment of the present invention, the adaptive array smart antenna constructs an input signal matrix with a predetermined number of input signals, computes a transmission signal matrix that minimizes a cost function using a first steering matrix set to an initial value and the input signal matrix, computes a second steering matrix that minimizes the cost function using the transmission signal matrix and the input signal matrix, maps the second steering matrix on a unit circle, constructs a third steering matrix with the mapped values, normalizes the third steering matrix and determining whether the third steering matrix converges, and demodulates data using the transmission signal matrix if the third steering matrix converges.

Abstract: A reception radio circuit 104 and a reception radio circuit 105 receive radio communication signals from a mobile station 109 and calibration signals from a CAL-CDMA radio signal transmission section 110 through respective a reception antenna 102 and a reception antenna 103, followed by performing down-conversion of received signals. A reception CDMA signal processing section B (for CAL) 107 measures characteristic errors of respective reception radio circuits while observing the calibration signals undergoing down-conversion, before holding the measured characteristic errors in a compensation table of a recorder 108. A reception CDMA signal processing section A (for communication) 106 performs CDMA demodulation processing of radio communication signals from the mobile station 109, which signals are subjected to the down-conversion, at the same time as observing operation of the reception CDMA signal processing section B (for CAL) 107, on the basis of the characteristic errors held in the compensation table.

Abstract: A radio equipment 1000 separates a signal of a specific terminal from signals from adaptive array antennas #1 to #4, based on a reception weight vector calculated by a reception weight vector calculator 20. Reception coefficient vector calculator 22 provides an impulse response of a signal propagation path of the specific terminal. A transmission coefficient vector estimator 32 predicts a propagation path at the time of transmission, from the result of estimation by the reception coefficient vector calculator 22. The transmission weight vector calculator 30 controls, based on the result of prediction by the transmission coefficient vector estimator 32, the antenna directivity at the time of transmission. Thus, degradation of error rate of the down link generated by the time difference between up/down links can be suppressed.

Abstract: A radar system and method for detecting and tracking a target of interest in the presence of interference, wherein the interference emits interfering signals, includes a receiver for receiving the interfering signals directly from the interference. The receiver also receives reflected signals, wherein the reflected signals is the interfering signals reflected by the target of interest. The interfering signals and the reflected signals are compared to detect the target of interest. In one embodiment, the reflected signals and the interfering are cross-correlated. The results of the cross-correlation are used to obtain range, position, and velocity information about the target of interest from a range/Doppler map.

Abstract: A signal detector is provided in which complex samples of a received signal are multiplied by data representative of a hypothesis, and the resulting product data is coherently integrated over a desired duration to provide correlation data representative of the level of correlation between the hypothesis and the signal. In one embodiment, the signal detector is part of a GPS receiver.

Abstract: A weight computation unit finds a weight used in a maximum ratio combining carried out on data sub-carrier signals for each user terminal. A direction vector computation unit finds direction vectors on the basis of the weight. A user separation weight computation unit finds a user separation vector on the basis of the direction vectors. A user separation combining unit uses the user separation vector to well separate a data sub-carrier signal transmitted by a predetermined terminal from data sub-carrier signals received from all terminals.

Abstract: To suppress interfering stationary targets in radar source data, a STAP filtering method is used. Filtering coefficients are determined, and filtering of the data takes place, in the frequency domain; the process is therefore limited to a few computing operations per matrix element of the range/Doppler matrix. Since, by means of the STAP filter according to the invention, the optimal filtering characteristics can be implemented, the stationary target suppression also functions in the range of the minor lobes of the antenna. Therefore, data of individual adjacent channels (L/R, left/right) can be processed as well as summation and difference signals (&Sgr;/&Dgr;).

Abstract: Method of obtaining a transmission gain function for an array of antennae communicating to a telecommunication terminal. The method includes determining a first weighting vector {overscore (b)}u maximizing on reception by the array a ratio (C/(Iu+Nu))u of a received signal coming from the telecommunication terminal to a noise plus interference disturbing an uplink channel, and calculating from the first weighting vector {overscore (b)}u a second weighting vector {overscore (b)}d maximizing on reception by the telecommunication terminal a ratio (C/(Id+Nd))d of a received signal coming from the array to a noise plus interference disturbing the downlink channel. The second weighting vector is in the form of a matrix product including a first noise matrix Du which is a function of a power of the first isotropic noise and/or a power of the first directional noise and a second noise matrix Dd which is a function of a power of the second isotropic noise and/or a power of the second directional noise.

Abstract: A method for estimating an arrival direction of a desired wave in which the arrival direction of the desired wave can be estimated even in case of existence of a multiple reflection wave. An identical signal series is repetitively transmitted two or more times from a transmitting side. The transmitted signal series is received by an array antenna having a plurality of element antennas on a receiving side. When the signal is received by each of the element antennas, cross-correlation is calculated between the signal series corresponding to the different repetition of the signal transmission from the transmitting side. Then, a MUSIC algorithm or an ESPRIT algorithm using the cross-correlation matrix is applied to estimate the arrival direction of the desired wave.

Abstract: A system and process for maintaining correlated contacts (e.g., sonar/radar contacts) utilizes diagonal averaging. A covariance matrix is formed from signals received by an array of sensors. These sensors may be acoustic and/or electromagnetic sensors. The covariance matrix is replaced with Toeplitz matrix. The Toeplitz matrix is a Toeplitz matrix that most closely matches the covariance matrix in the least squares sense. The Toeplitz matrix is used to calculate weight vectors for the adaptively formed response signals.

Abstract: The invention relates to a method for improving smart antenna array coverage. Arbitrary beam forming of an antenna array can be implemented by adjusting n antenna units beam forming parameter W(n), based on difference of size and shape between coverage required in engineering design and actually realized coverage. The method includes: setting an accuracy of W(n), i.e. an adjusting step length, setting a set of initial values W0(n), an initial value of mean-square error &egr;0, setting counting variable, setting threshold of ending adjustment M and maximum emission power of an antenna unit T(n). With the settings, a loop for W(n) adjustment is executed. A step-by-step approximation method is deployed for adjusting antenna radiation parameters, based on the minimum mean-square error criterion. Finally, an actual coverage of an antenna array approximates to the required coverage, under local optimization condition.

Abstract: A radar system including a blanker and a sidelobe canceler is described including an open loop nulling circuit for introducing one or more nulls in the main beam and a blanker beam. With this arrangement, the blanker can be operated even in the presence of strong sidelobe jamming without the conventional problems attributable to noise amplification. Also described is an antenna configuration for implementing the open loop nulling, including a pair of orthogonal linear arrays. One of the arrays is omnidirectional in azimuth and directional in elevation and the other array is omnidirectional in elevation and directional in azimuth in order to point the main and blanker beams in the direction of jammers. In one embodiment, the radar system further includes a spoofer and the crossed linear arrays process the spoofer signals on transmit and process blanker signals on receive.

Abstract: A system and method for measurement domain data association in a passive coherent location system is disclosed. According to the system and method, detection reports are received and associated with line tracks. The detection reports correlate to target signals received at the passive coherent location system. Measurements of the detection report correlate to the data of the target signals. A line track state estimation function associates new detection reports with the line tracks and estimates update states for the line tracks. A signal type is determined. Kalman filters are selected for the measurements according to the signal type. Measurement residuals are computed for the detection reports according to the Kalman filters. The detection reports are selected for association with the line tracks according to the residuals. The line tracks can be merged or terminated during updates according to specific criteria. Further, new line tracks are initialized as new targets are detected.

Abstract: A mobile station transmitted signal received at array antenna 11 is converted into an intermediate frequency signal in frequency conversion section 12, and converted into a digital signal in analog-digital conversion section 13. Arrival direction estimating section 15 estimates the number of mobile stations and directions thereof by processing the digital signal. Arrival direction tracking section 16 estimates a direction of a mobile station by sequential processing using an estimated result in arrival direction estimating section 15. Beam forming means 17 forms an antenna radiation beam to a direction of the estimated result in arrival direction tracking section 16.

Abstract: A radio section(RS) 102 receives, through antennas 101-1 through 101-3, a plurality of signals transmitted on a plurality of channels from a communication partner; demodulation sections(DS) 103-1 through 103-3 despread the signals of the channels; reception weight generation sections(RWGS) 104-1 through 104-3 generate reception weights 1 through 3 for the signals of the channels; respectively; a common weight generation section 105 generates, from the reception weights 1 through 3, a common reception weight, by which each of the signals of the channels is commonly multiplied; and multipliers 106-1 through 106-3 multiply each of the signals of the channels by the common reception weight. Thereby, the array antenna radio communication apparatus receives all of the signals of the channels with the same directional pattern.

Abstract: A system and method for forming a beam and creating nulls. The inventive method combines frequency domain suppression technology for narrow-band jammer rejection with orthogonal weighting using Eigen analysis for jammer nulling and signal beam-forming for an array antenna system. The inventive system is adapted for use with an adaptive array antenna having a plurality of radiating elements. The system includes a frequency domain suppressor connected to the array antenna and an orthogonal weighting subsystem connected to the frequency domain suppressor. In the illustrative implementation, signals received by each radiating elements are processed by an analog front-end and digitized. The frequency domain suppressor includes a Fast Fourier transformer (FFT) and a frequency domain suppressor for each element in the array. The frequency domain suppressor further includes a threshold evaluator which reads the signals output by the FFT's and provides threshold controls to the spectral suppressors.

Abstract: Methods, apparatuses and systems are provided for use in a wireless routing network. One apparatus, for example, includes an adaptive antenna that is configurable to receive a transmission signal from a transmitter and in response transmit corresponding outgoing multi-beam electromagnetic signals exhibiting a plurality of selectively placed transmission peaks and transmission nulls within a far field region of a coverage area. The adaptive antenna may also be configured to selectively receive at least one incoming electromagnetic signal directed through the coverage area. The adaptive antenna includes at least one antenna array and logic. The antenna array has a plurality of antenna elements. The logic is operatively coupled to the antenna array and configured to selectively control the placement of the transmission peaks and transmission nulls within the outgoing multi-beam electromagnetic signals.

Abstract: Process for estimating the correlation matrix of signals of unknown characteristics in an array of N sensors comprising the following steps:

Abstract: A system and method for narrowband pre-detection signal processing in passive coherent location applications is disclosed. A receiving subsystem receives a reference signal and a target signal from an uncontrolled transmitter. The target signal is reflected from a target. The passive coherent location system includes sub-processors that perform pre-detection operations on the reference and target signals. The functions include zero-doppler cancellation, quadrature demodulation, reference beam regeneration, coherent processing interval selection, power spectral density estimation, cross ambiguity function formation, and the like. Within these operations, the reference signal is filtered with respect to the target signal to form a first output reference signal. The first output reference signal is combined with the first target signal to form a first output target signal. The output target signal then is used for subsequent passive coherent location processing operations.

Abstract: The invention concerns a method and a device for receiving a signal transmitted by a source by means of a plurality of antennas, in which a plurality of beam signals are obtained by weighting the signals received by the different antennas. The beam signals are correlated with the replica of a reference signal transmitted by the said source and then combined by means of coefficients obtained from correlation results.

Abstract: In a Wireless Location System, reception and demodulation of signals is often performed at many sites. A collision may occur, e.g., in a TDMA, AMPS, GSM, GPRS, EDGE, CDMA, CDMA 2000, or WCDMA system, when a signal of interest (a transmission from a mobile transmitter to be located) and an interfering signal are received at the same time and at the same site. In the event such a collision occurs, the interfering signal may have been demodulated by a receiver system, or SCS, at another site, and the demodulated data be known by the TLP. This-interferer can be reconstructed and subtracted from the raw data representing the combined signal of interest and interferer at the site where the collision occurred. This technique can provide significant (e.g., approximately 10-15 dB) interference rejection, with little degradation to the signal of interest.

Abstract: In an adaptive antenna device having directivity pattern generators operable in accordance with different algorithms, respectively, in a baseband modem, beam steering processing, null steering processing, and estimating processing of an arrival direction are executed in parallel to one another. Parameters resulting from the beam and the null steering processing are controlled by processing results of the estimating processing and are weighted and combined to individually generate directivity patterns based on the different algorithms.

Abstract: A system and method for detection and feature extraction in a passive coherent location system is disclosed. During a coherent processing interval, detection and feature extraction operations are performed to determine peak detections and target parameters for targets. The system forms an ambiguity surface that has ambiguity surface data or the coherent processing interval. Bins from a previous ambiguity surface are associated with the ambiguity surface data. New bins are identified for new target echoes within the ambiguity surface. Peak detections are formed from the bins. The peak detections correlate to the target echoes of the coherent processing interval. Target parameters for the targets are estimated from the peak detections.

Abstract: In an adaptive array antenna receiving apparatus, signal to interference ratio (SIR) measuring units are provided in signal processing units, respectively. The SIR measuring units measure signal to interference ratios of existing fingers to supply the measured results for an antenna weight succession processing unit. The antenna weight succession processing unit selects one of the existing fingers on the basis of the measured results. The antenna weight succession processing unit extracts antenna weights from one of the signal processing units that corresponds to the selected finger. The antenna weight succession processing unit supplies the extracted antenna weights to a newly assigned finger or one of the existing fingers that path timing is greatly changed.

Abstract: The invention relates to a method for calibrating a smart-antenna array of a wireless access system using TDD, which antenna array comprises antenna elements with a transmit and a receive branch each. In order to enable a time stable calibration, it is proposed that at least some of the antenna elements are selected in turns to be employed for transmitting broadcast messages. This provides time periods in which only one of said elements is transmitting. Each transmit branch is connected to at least one of the receive branches of another element, signals transmitted via these connections being evaluated for calibration. If receive branches are connected to transmit branches of several elements, it is ensured with the proposed selection that during the broadcast periods these receive branches receive at the most a signal from one element, thus avoiding the need for switches. The invention equally relates to a corresponding radio transceiver unit and a corresponding calibration system.

Abstract: A signal detector is provided in which complex samples of a received signal are multiplied by data representative of a hypothesis, and the resulting product data is coherently integrated over a desired duration to provide correlation data representative of the level of correlation between the hypothesis and the signal. In one embodiment, the signal detector is part of a GPS receiver.

Abstract: An adaptive receiver includes an adaptive array unit and an equalizer unit. In the adaptive array unit, receiving signals of an array antenna are demodulated, weighted by multiplying with a complex weight calculated by an adaptive arithmetic unit, and adaptively combined. In the equalizer unit, propagation path estimation values are calculated from the receiving signals by a propagation path estimating unit, weighted with the complex weight by a complex weight adjusting unit, and adaptively combined. The combined demodulation signal is divided by the combined propagation path estimation value. Thereby, not only the unwanted signal wave of low correlation but also the unwanted signal wave of high correlation can be controlled effectively using an adaptive array antenna.

Abstract: The present invention relates to an arrival direction estimation method using an array antenna and a DS-CDMA receiver unit using this method. The method produces an accurate estimate of the arrival direction of a desired signal regardless of reception level and high interference. In a DS-CDMA communication system for performing a transmission by a spreading process using a code having a period longer than a symbol length, received signals from an array antenna are subjected to a despreading process by despreading units. A cross-correlation function with time lags of the recieved signals is obtained by inverse-modulating despread output signals by a known symbol in an inverse modulator. An arrival direction of a received signal is estimated by an arrival direction estimation unit based on the cross-correlation function. A beam former combines the despread output signals depending on the arrival direction and outputs an output signal to a channel receiver.

Abstract: In a cellular mobile telecommunications system the position of a mobile station can be estimated in terms of its bearing and range from a cell site. A multi-element direction finding antenna at the cell site receives signals from the mobile station and a receiver circuit estimates the bearing using the relative phase of signals received at different antenna elements and estimates the range by measuring round trip delay of signals to and from the mobile station. Motion of the mobile station can introduce errors into the bearing estimate due to frequency offset and frequency spread when element sampling is non-simultaneous. Compensation for these errors is introduced by using signal samples successively received at the same antenna element to estimate Doppler frequency offset and spread. It is necessary to ensure accurate calibration of the direction finding antenna and the receiver circuit.

Abstract: Recently, a smart antenna, i.e., a blind adaptive antenna array, has attracted much attention to suppress multiple access interference (MAI) and multipath signals to improve the capacity of a code division multiple access (CDMA) wireless communications system. Most of the smart antenna algorithms either need matrix computation or complex calculations. In this invented direction-of-arrival (DOA) tracking algorithm only 2M complex multiplications are required per snapshot. Further more the DOA tracking algorithm is not sensitive to the mixer phase distortions. Hence the system complexity is reduced since a separate phase calibration is not required for the DOA tracking algorithm. Also the equivalent DOA tracking error due to the mixer phase distortions is derived. Simulation results show that the DOA tracking algorithm in the present invention works effectively under additive white Gaussian (AWGN) as well as Rayleigh fading environments.

Abstract: A vehicle monitoring system provides real time monitoring of vehicles by receiving position and operational conditions from mobile units over a wireless communication link, such as a cellular telephony connection. In one embodiment, the mobile unit is equipped with both a Global Positioning System (GPS) receiver and a dead reckoning device, which provides position information when the GPS receiver is unable to receive GPS positions from a GPS satellite (e.g., when the vehicle is in a city area surrounded by tall buildings). A novel position request protocol allows multiple position reports to be included in a single data packet, thereby reducing the air time cost of transmitting data over a cellular telephony link. A novel antenna cable detects and reports tempering of a GPS antenna.

Abstract: A radio section(RS) 102 receives, through antennas 101-1 through 101-3, a plurality of signals transmitted on a plurality of channels from a communication partner; demodulation sections(DS) 103-1 through 103-3 despread the signals of the channels; reception weight generation sections(RWGS) 104-1 through 104-3 generate reception weights 1 through 3 for the signals of the channels, respectively; a common weight generation section 105 generates, from the reception weights 1 through 3, a common reception weight, by which each of the signals of the channels is commonly multiplied; and multipliers 106-1 through 106-3 multiply each of the signals of the channels by the common reception weight. Thereby, the array antenna radio communication apparatus receives all of the signals of the channels with the same directional pattern.

Abstract: Methods, apparatuses and systems are provided for use in a wireless routing network. One apparatus, for example, includes an adaptive antenna that is configurable to receive a transmission signal from a transmitter and in response transmit corresponding outgoing multi-beam electromagnetic signals exhibiting a plurality of selectively placed transmission peaks and transmission nulls within a far field region of a coverage area. The adaptive antenna may also be configured to selectively receive at least one incoming electromagnetic signal directed through the coverage area. The adaptive antenna includes at least one antenna array and logic. The antenna array has a plurality of antenna elements. The logic is operatively coupled to the antenna array and configured to selectively control the placement of the transmission peaks and transmission nulls within the outgoing multi-beam electromagnetic signals.

Abstract: Spatial profile creation section 102 creates an intensity distribution, that is, a spatial profile or spatial information of reception signals with respect to the directions of arrival of signals using reception signals prior to despreading received via antenna elements 101-1 to 101-4. Direction of arrival estimation section 103 estimates the directions of arrival of signals sent from other parties of communication from the spatial information created by spatial profile creation section 102 and divides and outputs the information of the directions of arrival to reception units 104-1 to 104-4 according to the direction of arrival. Beam formers 111 in reception units 104-1 to 104-4 each rotate the phase of the output reception signals from antenna elements 101-1 to 101-4 at predetermined angles based on the information of directions of arrival and combines these rotated reception signals so as to increase the reception levels of the signals sent from the directions of arrival.

Abstract: A system for detecting a predictable time varying signal within a noisy environment. Rather than merely comparing the output of a matched filter implementation to a threshold, a parallel reference is also generated by autocorrelating the weighting function from the matched filter. The original output and this reference are both acted upon by a mathematical operator and the two then compared for closeness of fit using a Chi-Square Goodness of Fit Test, a Mean Square Error Test, or some other test for closeness of fit. A value indicates the closeness of the two curves and is then compared to a threshold to determine whether the signal of interest is present or not.

Abstract: An antenna apparatus (and corresponding innate method) comprises an array of antenna elements each having a phase center. An “observable signal” that contains a low-frequency component and a high-frequency component is generated. The high-frequency component is summed with the signal received by each antenna element near its phase center, forming a plurality of sum signals. These are fed into a signal processing arrangement that processes these signals with the low frequency component of the observable signal, including analog to digital conversion to (i) remove the high frequency component of the observable signal, (ii) normalize the effects of the signal transfer characteristics on the digital sum signals, (iii) synchronously re-sample the digital sum signals, and (iv) differentially time-reference each digital sum signal to the phase center of the corresponding antenna element. The thusly, processed digital signals are combined into a single composite signal.

Abstract: In a multi-beam receiving apparatus, radio receiving sections receive radio signals through antenna elements. Correlators calculate code correlation values of desired wave signals contained in reception signals output from the radio receiving sections. Each first beam formation device forms a beam on the basis of all outputs from the correlators. Delay profile estimation sections individually generate delay profiles on the basis of the outputs from the first beam formation devices. A detector detects, on the basis of the outputs from the delay profile estimation sections, a reception timing of a multipath formed from the beams. Demodulators demodulate all the reception signals output from the radio receiving sections at the detected reception timing. Each second beam formation device forms a beam on the basis of all demodulation outputs from the demodulator. A synthesizer synthesizes the outputs from the second beam formation devices after weighting.

Abstract: A method for rapidly identifying which one of a plurality of mobile radio frequency (RF) terminals on-board a corresponding plurality of mobile platforms, such as aircraft, accessing a target transponded satellite, is causing interference with one or more non-target satellites orbiting in proximity to the target satellite. The method involves dividing the plurality of mobile RF terminals into two groups and commanding one group of terminals to stop transmitting. A check is then made to determine which group of terminals is causing the interference. That particular group is then subdivided successively by a factor of 2 and alternately checked to see if it is still causing the interference until a single mobile terminal is identified as the source of the interference.

Abstract: This invention relates to a signal processing method and apparatus for an adaptive array antenna. The objective is to suggest an adaptive procedure of computing the suboptimal weight vector for an array antenna system that provides a beampattern having its maximum gain along the direction of the mobile target signal source in a blind signal environment, where the transmitted data are not known (or not to be estimated) at the receiver. It is the ultimate goal of this invention to suggest a practical way of enhancing both the communication quality and communication capacity through the optimal weight vector of the array system that maximizes SINR(Signal to Interference+Noise Ratio).

Abstract: A method of operating a radio-based communications system is described. Signals from a plurality of mobile stations can be received by a plurality of antennae (11) of a base station (10). Profiles of the received signals can be calculated by a plurality of path-profiler-units (12). Specified individual values can be selected from the calculated profiles by a path-selector-unit (14). A plurality of rake-finger-units (16) can be assigned to the arrival times of the selected individual values. A predetermined number of path-profiler-units (12) are provided which can be distributed with the aid of a path-profiler-manager (13) between the plurality of antennae (11) and the plurality of mobile stations.

Abstract: A method and apparatus for measuring time related to satellite navigation data messages used with a satellite-based global positioning systems (GPS). A first record of at least a portion of a satellite data message is received at an entity, which is typically a base station of a wireless communication system. The first record is compared with a second record of the same satellite data message (navigation message) received by a GPS receiver. From the comparison, a time is determined indicating when the satellite date message was transmitted (broadcast). The comparison is made in a way that accounts for the only approximate removal of all modulation of the satellite data message by the acquisition and tracking stages of the GPS receiver.

Abstract: In an adaptive antenna receiving apparatus, a plurality of correlations between adjacent antennas are detected for each path, a fixed beam unique to each path arrival direction of the desired wave is formed on the basis of a vector generated by averaging the detected correlations, and each path is received and combined, or a plurality of correlations between adjacent antennas are detected for each signal sequence despread with a plurality of chip timings, a fixed beam unique to the arrival direction of each signal sequence is formed on the basis of a vector generated by averaging the detected correlations, and a path timing is detected on the basis of a delay profile generated from an output of each signal sequence, or a plurality of correlations between adjacent antennas are detected for each signal sequence despread with a plurality of chip timings, a fixed beam unique to the arrival direction of each signal sequence is formed on the basis of a vector generated by averaging the detected correlations, a path

Abstract: In a multiple propagation wave parameter measuring method, transmission waves are radiated into an outer space. The transmission waves are received as a multiple propagation wave. Arrival directions of the transmission waves are measured on the basis of reception signals. The transmission wave arriving from one direction of the measured arrival directions is defined as a desired wave, and the transmission waves arriving from remaining directions are defined as unnecessary waves. A weight with which a reception power ratio of the desired wave to the unnecessary waves becomes maximum is calculated. The reception signals are multiplied with the weight to extract the reception signal in which the unnecessary waves are suppressed. A change in delay time of the desired wave from a transmitting device to a receiving device is calculated on the basis of the reception signal in which the unnecessary waves are suppressed.

Abstract: This invention discloses an interference cancellation method based on smart antenna, which can solve various interference in mobile communication systems such as multipath propagation, etc., while using smart antenna. The invention includes the steps of: with a beam forming matrix, beam forming the output signal of a receiver based on smart antenna, then getting a set of digital signals NRk(m); canceling other users main path signal included in NRk(m), then getting another set of digital signals NSk(m), which only includes needed signals and all interference signals; searching in digital signal NSk(m) and getting all multipath interference signals coming from other users; canceling other multipath interference signal in NSk(m); and superposing the user main path and each multipath signal in phase coincidence, then getting a digital signal with interference canceled.