Abstract: A receiver includes an antenna array, a plurality of phase shifters, a matrix module, a low noise amplifier module, and a down conversion module. The antenna array is coupled to receive an inbound wireless signal. The plurality of phase shifters is coupled to the antenna array and to produce a plurality of phase shifted inbound wireless signals. The matrix module is coupled to beamform the plurality of phase shifted inbound wireless signals to produce a plurality of beamformed and phase shifted inbound wireless signals having a radiation pattern that is aligned with an angular position of a source of the inbound wireless signal with respect to the receiver.

Abstract: A receiver includes an antenna array, a plurality of phase shifters, a matrix module, a low noise amplifier module, and a down conversion module. The antenna array is operably coupled to receive an inbound wireless signal. The plurality of phase shifters is operably coupled to the antenna array and to produce a plurality of phase shifted inbound wireless signals. The matrix module is operably coupled to beamform the plurality of phase shifted inbound wireless signals to produce a plurality of beamformed and phase shifted inbound wireless signals. The low noise amplifier module is operably coupled to amplify one or more of the plurality of beamformed and phase shifted inbound wireless signals to produce one or more amplified inbound signals. The down conversion module is operably coupled to convert the one or more amplified inbound wireless signals into one or more baseband or near baseband signals.

Abstract: Methods and apparatus according to various aspects of the present invention operate in conjunction with a phased array system. The phased array system may include an array structural frame defining an array of module-receiving mounting locations. The phased array system may further include multiple array modules. Each array module may be adapted to be mounted in one of the mounting locations, and may include an antenna and a power source. The power source may supply power to the array module during an array transmit operation.

Abstract: A method is disclosed for mixed analog/digital beamforming in a wireless communication system having transmit and receive antennas and analog front-ends connected to either the transmit antennas or the receive antennas.

Abstract: A method and device for realizing smart antenna in WCDMA system are disclosed in the invention, including array antenna, radio frequency channel module, beam forming module, channel environment detection and classification module, beam-forming algorithm selection and weight value generation module. After processing the signals received by the antenna array in RF channel, the baseband array data X including multiple components is obtained, then the channel environment is estimated and identified according to the characteristics of said array data, and the channel type which the channel belongs to is determined; the corresponding adaptive beam forming algorithm is selected according to the identification result of the channel type, so as to calculate the uplink weight value W including multiple components; said array data X and weight value W are multiplied so as to form beam Y.

Abstract: A beamformer is arranged to receive an input from a first antenna element and from at least one other antenna element and to generate at least a first and second output beam. The first and second output beams are combined at a connecting port such that signals received at the first antenna element are constructively combined at the connecting port and signals received at another antenna element or elements are destructively combined at the connecting port, so that a receiver connected to the connecting port may receive signals from the first antenna element and may not receive signals from the other antenna element or elements. The arrangement may also be used to transmit a signal which is fed into the connecting point from the first antenna element and not from the other antenna element or elements.

Abstract: The present invention relates to a first node (1) in a wireless communication system (2), where the first node (1) comprises at least two antenna ports (3, 4), and is arranged for communication with a second node (5) via a channel (H) by means of at least one antenna radiation lobe (6, 7, 8, 9). The second node (5) comprises at least two antenna ports (10, 11) and is positioned at a certain direction (12) in relation to the first node (1), and is arranged for transmitting one of at least two precoding weight set requests to the first node (1) at certain times. Each transmitted precoding weight set request is chosen in dependence of the channel (H) such that the first node (1) receives instructions for a certain beam-forming. The first node (1) is arranged to apply such a beam-forming that the precoding weight set requests received from the second node (5) have one certain distribution, of a set of at least one certain distribution, over a certain time period.

Abstract: Described is a method of modifying an antenna pattern for a phased array antenna having at least one failed antenna element. A number of proximate beamformers in a proximate angular region about a beamformer at an angle of interest are determined. Each of the proximate beamformers has a proximate beamformer weight vector. A corrected beamformer weight vector is determined for the angle of interest as a linear combination of the proximate beamformer weight vectors. Each element of the corrected beamformer weight vector that corresponds to one of the failed antenna elements has a value of zero. The method enables computation of low spatial sidelobe antenna patterns without requiring a recalibration of the antenna thereby enabling uninterrupted operation of systems that employ phased array antennas. The method can also be used to control taper loss or sidelobe level for phased array antennas that have no failed antenna elements.

Abstract: A distributed control system for an active array antenna system is disclosed. In an exemplary embodiment, the array system employs many transmit/receive (T/R) modules each with an associated radiator element, a phase shifter element and a set of RF switch elements to set the module to transmit or receive modes. The array system is arranged to generate a transmit or receive array beam. The distributed control system in an exemplary embodiment includes an array processor for controlling the array, the processor configured to generate command signals to set the T/R module elements to transmit or receive mode and to steer the array beam to a desired direction. The command signals to steer the array beam include phase slopes common to all T/R modules in a given array or subarray.

Abstract: A radar apparatus comprises a substrate having first and second sides, an antenna including radiative elements disposed on the first side of the substrate, a Butler matrix supported by the substrate having input and output ports, where each output port of the Butler matrix is electrically connected to a group of radiative elements, and input connections between a radio-frequency (RF) circuit and the input ports of the Butler matrix. The RF circuit may be supported by the second side of the substrate.

Abstract: System and method for calculating a transmitter beamforming vector related to a channel vector h under per-antenna power constraints combined with total power constraint, under per-antenna power constraints combined with overall line of site (LOS) effective isotropic radiated power (EIRP) and under all three constraints. Calculating a transmitter beamforming vector may be done in the transmitter, in the receiver and feedback to the transmitter or in both. The method may be adapted to perform with a multi-antenna receiver and with multi-carrier systems.

Abstract: A low sidelobe beam forming method and dual-beam antenna schematic are disclosed, which may preferably be used for 3-sector and 6-sector cellular communication system. Complete antenna combines 2-, 3- or -4 columns dual-beam sub-arrays (modules) with improved beam-forming network (BFN). The modules may be used as part of an array, or as an independent 2-beam antenna. By integrating different types of modules to form a complete array, the present invention provides an improved dual-beam antenna with improved azimuth sidelobe suppression in a wide frequency band of operation, with improved coverage of a desired cellular sector and with less interference being created with other cells. Advantageously, a better cell efficiency is realized with up to 95% of the radiated power being directed in a desired cellular sector.

Abstract: A method and system for beamforming signal transmission under a per-antenna power constraint is presented. In one aspect, a multiple input multiple output (MIMO) transmitting station may compute a per-antenna power gain factor for each of a plurality of transmit chain signals. The transmit chain signals may be concurrently transmitted by a plurality of transmitting antennas at the MIMO transmitting station. The plurality of transmit chain signals may correspond to beamforming signals, which are generated by performing spatial mapping on a plurality of space-time signals. The plurality of power gain factors may be computed based on a per-antenna power constraint. Alternatively, the plurality of power gain factors may be computed based on joint per-antenna power and total-power constraints. Each of the transmit chain signals may be amplified or attenuated based on the corresponding antenna gain factor. The amplified or attenuated signal is then transmitted by the corresponding transmitting antenna.

Abstract: An antenna system and electronic scanning method that employs feed subarray electronic offset beam scanning. The system includes a feed element containing an array of electronic transmitting/receiving elements. The system further includes a reflector for reflecting signals received from the feed element to a target region, and for reflecting signals received from a target region to the feed element. Electronic beam scanning is achieved by activating and deactivating in turn subarrays within the array of transmitting/receiving elements of the feed element.

Abstract: Described herein are systems and methods that eliminate the need for costly and complex switching networks for routing channelized data between antenna elements and beamformers. In one aspect, a beamforming system comprises a beamformer for each antenna element of an antenna array, in which the beamformers for the different antenna elements are arranged in parallel. The beamforming system also comprises a combiner that combines the outputs of the beamformers into a single beam. In one aspect, the beamformers of antenna elements that do not contribute to a desired beam output zeros to the combiner, which when added to the subbeams of the other beamformers have no affect of the final beam. In another aspect, operations (e.g., multiplication, memory reads) of each beamformer that does not contribute to a desired beam may be turned off to conserve power.

Abstract: Provided are a multiple-input multiple-output (MIMO) radar apparatus and a wireless communication method using the same. The MIMO radar apparatus includes a transmitter generating and transmitting different signals having a frequency modulated continuous wave (FMCW) form to a moving object as a target through transmitting antennas of a transmitting antenna array respectively, and a receiver receiving echo signals which are the signals transmitted through the transmitting antennas and reflected from the moving object through receiving antennas of a receiving antenna array respectively. At least one of the transmitting antenna array and the receiving antenna array is a planar antenna array.

Abstract: The present invention relates to an array antenna arrangement comprising at least two antenna sub-arrays and at least one antenna element in each antenna sub-array. The array antenna arrangement is adapted for calculation of a total covariance matrix (R) of a received signal vector (x). The array antenna arrangement further comprises at least one switch, where the number of switches corresponds to the number of antenna elements in each antenna sub-array. Each switch is connected to a respective radio chain, and is arranged to connect the antenna elements of a respective corresponding antenna sub-array to the respective radio chain cyclically. At least one full switch cycle, comprising a set of received signals for each switch configuration, is carried out for a calculation of the total covariance matrix (R). The present invention also relates to a corresponding method.

Abstract: A system and method for coordinated spatial multiplexing using second order statistical information is provided. A method for controller operations includes receiving second order statistics from a plurality of communications devices, computing a beamforming vector for each communications device in the plurality of communications devices, selecting a subset of communications devices from the plurality of communications devices to receive transmissions, and transmitting transmissions to the subset of selected communications devices. The beamforming vector for a communications device is based on the second order statistics provided by the communications device, and the transmitting uses the computed beamforming vector for each selected communications device to transmit the transmissions to the selected communications device.

Abstract: A beam-forming network having: a plurality (NI) of input signal ports (IP); a plurality (NO) of output signal ports (OP); a weighting and interconnecting network (WIN) comprising a plurality of signal dividers (SD), phase and amplitude weighting elements (WE), switches (SW1, SW2) and signal combiners (SC), for associating each input port to output ports through respective weighting units; wherein either input (IP) or output (OP) ports, or both, are partitioned into disjoint equivalence classes (IEC, OEC), at least a majority of said equivalence classes having more than one port; and in that the network is either configured in order to associate each input port to at most one output port for each output equivalence class, or to associate each output port to at most one input port for each input equivalence class, or both. Also provide is a multibeam antenna comprising having such a beam-forming network, and an electronic circuit for implementing such a beam-forming network.

Abstract: This invention relates to the use of a sufficiently-sampled auxiliary array in combination with one or more under-sampled sub-arrays. The sufficiently-sampled auxiliary array is used to create a signal-free reference (SFR) beam that contains grating lobe interference. The SFR may be used to cancel the interfering grating lobe in an under-sampled main beam by coherently eliminating or subtracting the SFR from the main beam. Exemplary aspects of the invention thus support significant under population of the full aperture and avoid the problems and limitations of previous solution, with consequent savings in sensor hardware cost and weight.

Abstract: A vertically integrated electronically steered phased array that employs beamsteering using a programmable phase locked loop including a local oscillator. The local oscillator provides an oscillator signal that is converted to an RF signal that can be either up-converted for a transmit operation or down-converted for a receive operation. The relative off-set between independently generated local oscillator signals forms the basis of the off-set phase required for a phased array. The absolute measure of off-set phase is referenced to a globally distributed clock signal that aligns the zero degree phase shift of the oscillator.

Abstract: A phased array antenna system with two dimensional scanning includes a two dimensional array A of antenna elements A1,1 to A12,12 arranged in lines; each line is associated with a respective first rank corporate feed network 161 to 1612 having outputs 171,1 to 1712,12 connected to respective antenna elements A1,1 to A12,12 and inputs for variable relative phase input signals. These corporate feed networks each have first and second inputs A1/B1 to A12/B12 connected respectively to outputs 171 CD/1712CD to 171EF/1712EF of different second rank corporate feed networks 16CD and 16EF. The corporate feed networks 161 to 16EF convert input signals of variable relative phase into relatively greater numbers of output signals for a phased array.

Abstract: The invention concerns a network for distributing a plurality of input microwave signals into a plurality of output signals having a Gaussian amplitude and in-phase distribution per said input signal, the network comprising: a plurality of N input ports providing N different input signals; a plurality of M output ports, M being a multiple number of N; a plurality of P layers disposed between the inputs ports and the outputs ports, the input signals being distributed through these layers, each layer comprising an arrangement of power combiners (C) and/or power dividers (D), the arrangement is self similar with an angular rotation of k2?/N radian around the symmetry axis (AA?) of the polygonal closed shape formed by said input ports, k being an integer comprised between 1 and N.

Abstract: A method and system for analog beamforming in a wireless system is provided. Analog beamforming involves performing an iterative beam acquisition process based on beam search training, determining transmit and receive beamforming vectors including phase weighting coefficients, based on the iterative beam acquisition process. Each iteration includes estimating the receive and transmit beamforming coefficients alternatively, until the receive and transmit beamforming coefficients converge.

Abstract: A method and apparatus for performing blind signal separation in an orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) system are disclosed. A transmitter generates a plurality of spatial streams of data and transmits the spatial streams via a plurality of transmit antennas. A receiver receives the transmitted spatial data streams with a plurality of receive antennas and generates a plurality of receive data streams. The receiver performs a discrete Fourier transform (DFT) on each of the receive data streams to generate a plurality of frequency domain data streams. The receiver then performs a blind signal separation on the frequency domain data streams to recover spatial streams transmitted by the transmitter. The blind signal separation may be performed by using an independent component analysis (ICA) in the complex domain. The blind signal separation may be performed individually for each OFDM subcarrier.

Abstract: A method for synthesizing an array factor for an array antenna based on a target shape of an array factor amplitude, includes: calculating an array factor phase based on the target shape of the array factor amplitude, and calculating array antenna weight coefficients using the least mean square method, where a target function used in the least mean square method is a complex function composed by the target shape of the array factor amplitude and the calculated array factor phase, wherein the calculated weight coefficients determine the array factor.

Abstract: Adaptive antenna beamforming may involve a maximum signal-to-noise ratio beamforming method, a correlation matrix based beamforming method, or a maximum ray beamforming method. The adaptive antenna beamforming may be used in a millimeter-wave wireless personal area network in one embodiment.

Abstract: Techniques are provided to improve receive beamforming at a wireless communication device that receives energy in a frequency band at M plurality of antennas, where the received energy includes desired signals and interference signals. The wireless communication device has no knowledge of the spatial signatures of the desired signals and interference signals. A weighted sum signal vector is computed from the received signals and a covariance matrix is computed from the receive signals. Eigenvalue decomposition of the covariance matrix is computed to obtain M eigenvalues of corresponding M eigenvectors of the covariance matrix. A correlation rate is computed between the M eigenvectors and the weighted sum signal vector. A combined receive beamforming and nulling weight vector is computed from the M eigenvectors and the weighted sum signal vector and based further on the correlation rate.

Abstract: A beamforming apparatus obtains the beamforming parameters that realize arbitrary desirable PSF by using optimization theories. The apparatus uses at least one of the beamforming parameters such as the intensities, frequencies, bandwidths and shapes of the signals transmitted by the transmitting unit, the filtering of noises, amplifications (gains) and shapes of the signals received by the receiving unit, delays of the directions of propagation and array used by the delay units, apodization functions of the directions of propagation and array used by the apodization units, the number of the additions of the signals by the addition unit, array element parameters such as element size or shape and how to implement the elements in transducers (e.g., connections by leads between the elements and with the surroundings), which are determined by the specified optimization process to realize the desirable PSF.

Abstract: The Energy spectral density of OFDM signals inherently rolls off slowly. Slow OFDM spectral rolloff has system level implications traditionally mitigated by some combination of the following: addition of bandlimiting filtering; use of significant guard bands of zeroed tones; and, guard time shaping. Each of these techniques negatively impact system performance and/or flexibility. This application presents a methodology for active cancellation of out of band spectral energy. The technique can be used by itself or in conjunction with above traditional methods to help control out of band emission. Examples of the use of the new technique are provided. Computational cost of the new technique is also discussed.

Abstract: A low cost radar system that employs monopulse beamforming to detect objects in the road-way both in elevation and azimuth. In one non-limiting embodiment, a beamforming receiver architecture includes a first beamforming device and a plurality of antennas coupled to the first beamforming device, and a second beamforming device and a plurality of antennas coupled to the second beamforming device. The first and second beamforming devices are oriented 90° relative to each other so that the receive beams provided by the first beamforming device detect objects in azimuth and the receive beams provided by the second beamforming device detect objects in elevation. A first switch is provided to selectively couple the sum pattern signal from the first and second beamforming devices to one output line, and a second switch is provided to selectively couple the difference pattern signals from the first and second beamforming devices to another output line.

Abstract: Techniques are provided herein to detect ranging codes in energy received at a plurality of antennas of a wireless communication device. Energy is received at a plurality of antennas of a first wireless communication device and received signals are generated from the received energy. The received energy comprises a ranging transmission from one or more second wireless communication devices, wherein each ranging transmission comprises a ranging code selected from a set of possible ranging codes. A ranging code specific receive beamforming weight vector is generated for a ranging code in the set of possible ranging codes from the received signals. The ranging code specific receive beamforming weight vector is applied to corresponding ranging code specific signals derived from the received signals to produce ranging code specific beamformed signals. The ranging code specific beamformed signals are correlated to produce correlation results.

Abstract: The present invention provides a reduced or compact sized Butler matrix with improved performance for use in beam forming antennas and beam forming networks (BFN) applications. The reduced or compact size of the Butler matrix is enabled by shorter transmission lines between the hybrid elements as a result of using multi-layer support surfaces with substantially parallel and overlapping hybrid elements disposed thereon. Moreover, the conductive through traces of the hybrid elements have inwardly projecting and mutually approaching portions, thereby decreasing the distance between the inputs and outputs of the hybrid elements and thus reducing the size of the Butler matrix. Comparing to antennas implemented using traditional Butler matrices, antennas incorporating the present matrix can approximately reduce effective antenna area by half in bi-sector array applications, and are more suitable for complex beam forming antennas such as downtilt antennas or arrays.

Abstract: The present invention relates to a method for the operation of an antenna group (1) having M?2 transmitters and N?2 receivers (3) for the digital beamforming. In the method, a coherent transmit signal is transmitted in a transmit-receive-cycle via each of the M transmitters (2) into an area to be monitored, and a coherent receive signal from the area is recorded by each of the N receivers (3) for each transmit signal so that M·N receive signals are obtained. To each receive signal, a combination of the respective transmitting transmitter (2) and the respective receiving receiver (3) is allocated. The M·N receive signals are processed by means of digital beamforming to obtain spatial information about objects in the area to be monitored.

Abstract: A first network device includes a calibration module configured to receive a training signal from a second network device. The training signal indicates the second network device is capable of adjusting beamforming weights associated with the second network device based on a steering matrix received from the first network device. A steering module is configured to determine a first steering matrix for the second network device based on the training signal. The steering module is configured to transmit the first steering matrix to the second network device for adjustment of the beamforming weights associated with the second network device.

Abstract: An embodiment of the present invention provides an apparatus, comprising a plurality of sub-arrays and at least one beamformer driving the plurality of sub-arrays, the at least one beamformer employing at least one phase shifter.

Abstract: A retro-directive antenna for communicating with a geostationary satellite autonomously detects the direction from which a signal is received, and transmits a beam that points back along the same direction. An array feed is used to illuminate a parabolic reflector. Each feed element of the retro-directive antenna is associated with a unique pointing direction of the beam in the far field. As the transmit energy is switched to different feed elements, the far-field beam is scanned, making it possible to track a geostationary satellite in a slightly inclined orbit. This eliminates the need for mechanical tracking and maintains high antenna gain in the direction of the geostationary satellite. The use of a toroidal reflector with multiple linear array feeds spaced in the azimuth direction enables multi-beam operation, allowing multiple geostationary satellites, spaced by up to fifteen beam widths in azimuth, to be tracked simultaneously and independently.

Abstract: Techniques are provided to compute beamforming weights at a communication device, e.g., a first communication device, based on transmissions received at a plurality of antennas from another communication device, e.g., a second communication device. A plurality of transmissions are received at the plurality of antennas of the first communication device from the second communication device. A covariance matrix associated with reception of a plurality of transmissions at the plurality of antennas of the first communication device is computed. Corresponding elements (e.g., all the rows or all the columns) of the covariance matrix are combined to produce a weighted channel signature vector. A receive beamforming weight vector is computed from the weighted channel signature vector.

Abstract: A system and method are provided for configuring an antenna array having a predetermined number of antennas. After providing an antenna correlation matrix for all antennas with regard to a mobile terminal, the antenna array is virtually partitioned into two or more sub-arrays based on the antenna correlation matrix such that correlations among antennas within each sub-array are higher than correlations among antennas belonging to different sub-arrays. One or more beamforming weights are generated corresponding to each antenna within the sub-arrays for applying to one or more signals transmitted therefrom, and at least one predetermined multiple-input-multiple-output (MIMO) mechanism is further applied among the sub-arrays by treating each sub-array as a virtual antenna.

Abstract: Techniques are provided for improving hybrid automatic repeat request retransmissions techniques in a beamformed multiple-input multiple-output wireless communication environment. At a first device comprising a first plurality of antennas, a plurality of beamforming weight vectors are applied to a corresponding plurality of signal streams for simultaneous transmission to a second device having a plurality of antennas. A determination is made whether the plurality of signal streams need to be retransmitted from the first device to the second device. When a retransmission needs to be made, an order in which the plurality of beamforming weight vectors are applied to the plurality of signal streams is switched for a retransmission attempt of the plurality of signal streams from the first device to the second device.

Abstract: A beamformer includes a number (T) of consecutive combining stages. A Tth combining stage includes a converging unit. Each of first to (T?1)th combining stages includes a plurality of converging units. The number of the converging units in a preceding combining stage is greater than that of a succeeding combining stage. Each converging unit in the first combining stage combines three arrival signals from an antenna array in accordance with corresponding weights so as to form an output signal. Each converging unit in each of second to (T?1)th combining stages combines output signals of three corresponding converging units in an immediately preceding combining stage in accordance with corresponding weights so as to form an output signal. The converging unit of the Tth combining stage combines the output signals from the converging units in the (T?1)th combining stage in accordance with corresponding weights so as to form an output signal that serves as an array pattern.

Abstract: In an exemplary embodiment, a monolithic active solution is configured to generate the fixed spatial beams of a Butler matrix operation or a Blass matrix operation. The exemplary Butler matrix comprises active RF hybrids and vector generators, and is designed for broadband performance in an ultra-compact size, which is size independent of the operating frequency. Furthermore, an exemplary Blass matrix comprises vector generators, active power combiners, and active power splitters. The Blass matrix is designed for broadband performance in an ultra-compact size, which is size independent of the operating frequency. Both the exemplary Butler matrix and exemplary Blass matrix may be configured generate steerable beams. Advantages of both the exemplary Butler matrix and exemplary Blass matrix include that they have neutral or slight positive power gain rather than high losses, and have ultra broadband range which enables operation over multiple frequency bands.

Abstract: Examples of the present invention include a radar apparatus comprising a substrate, an antenna disposed on a first side of the substrate, a Butler matrix supported by same the substrate, output ports of the Butler matrix being electrically connected with a group of radiative elements; and input ports configured to be in communication with a radio frequency (RF) circuit. The RF circuit may be supported proximate or adjacent the substrate.

Abstract: A base station is capable of transmitting a signal in a wireless communication network. The base station decides channel state information matrices of respective channels by determining a state of the channels corresponding to respective transmission antennas. The base station calculates transmission beam forming vectors for the respective transmission antennas by a combination of a dot product and a cross product of the channel state information matrices. Thereafter, the base station beam-forms signals for the respective transmission antennas by using the respective transmission beam forming vectors, and transmitting the beam-formed signals.

Abstract: An apparatus and method for removing interference in a transmitting end of a multi-antenna system are provided. The method includes receiving channel information for all Receive (Rx) antennas; calculating a beam-forming matrix that maximizes a Signal-to-Interference plus Noise Ratio (SINR) for each Rx antenna by using the received channel information; calculating an integer value which is in proportion to an interference signal for each Rx antenna by using the received channel information and the calculated beam-forming matrix, and performing Dirty Paper Coding (DPC) on a Transmit (Tx) signal by using the calculated integer value; and performing beam-forming by multiplying the Tx signal that has undergone the DPC by the calculated beam-forming matrix. Accordingly, a highest data rate for each user and a highest diversity can be obtained.

Abstract: Methods, systems and apparatus for ground-based beamforming of a satellite communications payload (200) within a satellite communications network (100). An embodiment of the invention comprises a satellite (11) communicatively coupled to at least one gateway (12) via a feeder link (13) and further coupled to a plurality of user terminals (16), each communicatively coupled with the satellite by a user link (17). A ground based beam forming system (400) measures and corrects amplitude and phase errors of a plurality of return path signals (452) traveling from the user terminals (16) via the satellite (11) to the at least one gateway (12), and measures and corrects amplitude and phase errors of a plurality of forward path signals (457) traveling from the at least one gateway (12) via the satellite (11) to the user terminals (16).

Abstract: An adaptive antenna array control system and associated method is provided for continuously and automatically assigning resources to either protect against strong interferers or to shade a spatial region, reducing gain in that spatial region, to protect against potential low power interference, thus providing improved adaptive interference cancellation system performance with limited resources. The Array biasing system is provided as an element of an adaptive antenna array control loop.

Abstract: A method and apparatus for a simplified approach for determining the output of a total covariance signal processor. A single set of offline calculations is performed and then used to estimate the output of the total covariance signal processor. A simplified approach for performing matrix inversion may also be used in determining the output of the total covariance processor.

Abstract: A method for determining beamforming weights used onboard a satellite and ground-based beamforming weights used in a ground-based station as part of a satellite communication system. This beamforming method is a two-stage beamforming process that requires a reduced downlink bandwidth between the satellite and the ground-based station yet achieves optimal signal-to-noise ratio for bandwidth allocated for the downlink. values for the fixed onboard beamforming weights are computed to yield a maximum, max A ? ( min U ? S N ? ? W = W ? ) , where the maximum is computed over all possible fixed weights A represented by an L×M matrix, the minimum is computed over all possible positions of remote communication devices U, and the signal-to-noise ratio (S/N) is computed for the optimal set of ground-based beamforming weights W={hacek over (W)}.

Abstract: The method for beamforming in a wireless communication system comprises the steps of: receiving a sounding packet so as to estimate channel state information between a transmitter and a receiver; generating a beamforming matrix in accordance with the channel state information; generating a beamforming steering matrix by multiplying the beamforming matrix by a rotation matrix; and feeding back the beamforming steering matrix.