76 results about "Downlink beamforming" patented technology

A multi-user MIMO downlink beamforming system with limited feedback (200) is provided to enable preceding for multi-stream transmission, where a channel codeword (ui) and one or more channel quality indicator values (CQIA, CQIB) are computed at the user equipment (201.i) on the basis of maximizing a predetermined SINR performance metric (ρi) which estimates the receive signal-to-noise-ratio (SINR) at the user equipment (201.i). The computed codeword (ui) and CQI values (or differential values related thereto) are quantized and fed back to help the base station (210) which applies a correction to the appropriate CQI value in the course of designing the transmit beamforming vectors w and determining the appropriate modulation and coding level to be used for downlink data transmission.

Provided is a method and apparatus for determining a downlink beamforming vector in a hierarchical cell communication system. Small base stations may determine transmit beamforming vectors of the small base stations so that interference from the small base stations may be reduced in a macro terminal. A macro terminal and small terminals may determine receive beamforming vectors based on the transmit beamforming vectors of the small base stations. A macro base station may determine a transmit beamforming vector based on effective channels to terminals using the receive beamforming vectors of the terminals.

A multi-user MIMO downlink beamforming system (200) is provided to enable transmit beamforming vectors to be efficiently provided to a subset of user equipment devices (201.i), where spatial separation or zero-forcing transmit beamformers (wi) are computed at the base station (210) and used to generate precoded reference signals (216). The precoded reference signals (216) are fed forward to the user equipment devices (201.i) which apply one or more hypothesis tests (207.i, 208.i) to the precoded reference signals to extract the precoding matrix (W), including the specific transmit beamforming vector (wUE) designed for the user equipment, and this extracted information is used to generate receive beamformers (vi).

A multi-user MIMO downlink beamforming system with limited feed forward (200) is provided to enable preceding matrix information to be efficiently provided to a subset of user equipment devices (201.i), where zero-forcing transmit beamformers (wi) are computed at the base station (210) and assembled into a precoding matrix (W). The precoding matrix is encoded using a compact reference signal codebook (225, 207.i) for forward link signaling, either by sending bits indicating the index of the transmission matrix used, or by transmitting one or more precoded pilots or reference signals wherein the pilot signals are precoded using vectors uniquely representative of the transmission matrix used which includes candidate reference signal matrices which meet a predetermined condition number requirement, such as a condition number threshold. The preceding matrix information (227) is extracted at the user equipment devices (201.i) using the compact reference signal codebook (207.i) and used by the MMSE receiver (209.i) to generate receive beamformers (vi).

Dedicated pilot signals are transmitted from a transmitting device to a receiving device through a multicarrier MIMO channel in addition to data signals and common pilot signals. The dedicated pilot signals may be used by the receiving device to validate whether a predetermined beamforming matrix (i.e., a beamforming matrix identified by the receiving device) was used by the transmitting device to precode the transmitted data. If a different beamforming matrix was used for the preceding, the receiving device may use this matrix to demodulate the received data.

A TDD antenna array S-CDMA system for increasing the capacity and quality of a wireless communications is disclosed. By simultaneous exploiting the spatial and code diversities, high performance communications between a plurality of remote terminals and a base station is achieved without sacrificing system flexibility and robustness. The time-division-duplex mode together with the inherent interference immunity of S-CDMA signals allow the spatial diversity to be exploited using simple and robust beamforming rather than demanding nulling. Measurements from an array of receiving antennas at the base station are utilized to estimate spatial signatures, timing offsets, transmission powers and other propagation parameters associated with a plurality of S-CDMA terminals. Such information is then used for system synchronization, downlink beamforming, as well as handoff management. In an examplary embodiment, the aforementioned processing is accomplished with minimum computations, thereby allowing the disclosed system to be applicable to a rapidly varying environment. Among many other inherent benefits of the present invention are large capacity and power efficiency, strong interference / fading resistance, robustness power control, and easy hand-off.

Spatial Division Multiple Access (SDMA) offers multiplicative spectral efficiency gains in wireless networks. An adaptive SDMA beamforming technique is capable of increasing the traffic throughput of a sector, as compared to a conventional tri-cellular arrangement, by between 4 and 7 times, depending on the environment. This system uses an averaged covariance matrix of the uplink signals received at the antenna array to deduce the downlink beamforming solution, and is equally applicable to Frequency Division Duplex (FDD) and Time Division Duplex (TDD) systems. A scheduling algorithm enhances the SDMA system performance by advantageously selecting the users to be co-scheduled.

A downlink beamforming apparatus and method. In one embodiment, a method in accordance with the teachings of the present invention includes receiving uplink communication signals from a plurality of antenna array elements, selecting an operating condition of an environment and estimating downlink beamforming weights used in downlink communication signals in response to the selected operation condition of the environment.

The present invention provides a method for reducing the bandwidth of an Ir interface, which is applied to a remote baseband system that introduces a beamforming function. The method includes: when sending downlink, the indoor baseband processing unit BBU transmits The downlink user data and downlink control signals are sent to the remote radio unit RRU, and the RRU performs downlink beamforming processing according to the downlink user data and downlink control signals; when receiving uplink, the BBU sends the uplink control signals to the RRU through the Ir interface , the RRU performs uplink equalization processing on the received uplink user data according to the uplink control signal, and sends the equalized uplink user data obtained after the uplink equalization processing to the BBU through the Ir interface. The present invention also provides a distributed base station corresponding to the above method. The application of the present invention can greatly reduce the bandwidth requirement of the Ir interface, and increase the effective data occupancy ratio of the Ir interface.

An apparatus for allocating orthogonal codes to mobile stations for use in a CDMA base station that transmits using an adaptive antenna array. The apparatus comprises a database for storing R records. Each record is associated with an active mobile station and comprises an active orthogonal code associated with the active mobile station, corresponding downlink beamforming coefficients associated with the active mobile station, and mobility information associated with the active mobile station. The apparatus further comprises a controller for comparing estimated downlink beamforming coefficients associated with a new mobile station to the R records. The controller selects a first active orthogonal code associated with a first active mobile station to communicate with the new mobile station. The selection is based on the degree of correlation between the estimated downlink beamforming coefficients and first corresponding downlink beamforming coefficients, and 2) first mobility information associated with the first active mobile station.

An apparatus and method are provided for beamforming in a MIMO wireless communication system. A base station includes a first calculator that repeatedly calculates downlink beamforming vectors of the user terminals to calculate the optimal beamforming vectors for the user terminals, a quantizer that quantizes the downlink beamforming vectors in order to transmit information of the downlink beamforming vectors, a control channel transmitter that feeds forward information of the quantized downlink beamforming vectors to the user terminals, a second calculator that calculates the final downlink beamforming vectors of the user terminals, and a beamforming transmitter that sums the beamformed TX signals of the user terminals and transmits the summed TX signals through a plurality of TX antennas.

This invention relates to one mobile communication intelligent antenna down linkage wave beam endows method, which is characterized by the following: the basic station measures and feeds back the linkage signals to adjust the down linkage-weighted vector. The advantages of this invention lie in the following: a, of not strict requirement of aptitude and phase of receiving and emission channels; b, suitable for upper and down linkage and easy for wireless environment and suitable for wireless environment; c, without strict correction of receiving and emission channels.

A system and method is disclosed for improving downlink performance of an adaptive antenna array in a vehicular environment. The system comprises a mobile station that has a first mobile antenna and a second mobile antenna. A spatial signature estimator associated with a base transceiver station obtains spatial signatures from signals from the first mobile antenna and from the second mobile antenna within an uplink interval. Correlation circuitry uses the spatial signatures to identify a least changing spatial signature to obtain an optimal downlink beamforming weight vector to be used in the transmission of a signal to the mobile station in the next downlink interval.

A method for downlink beamforming in a frequency-division-duplex wireless communications system comprising a base station with an antenna array and terminals that are physically remote from said base station, the method comprising the steps of: receiving at said base station antenna array combinations of arriving uplink signals from said plurality of remote terminals, estimating an uplink beamforming weight vector for each of said terminals from said combinations of arriving uplink signal; identifying uplink nulls and an uplink main beam position from said uplink beamforming weight vector; transforming each of said uplink nulls to form a corresponding downlink null; generating a downlink beamforming weight vector from all downlink nulls; and transmitting a set of information signals from said base station antenna array according to said downlink. beamforming weights.

The disclosed embodiments relate to a system and method for providing user specific beams in a fixed beam network, the fixed beam network comprising a plurality of fixed beams, each of the plurality of fixed beams being defined by a plurality of fixed beam correlation coefficients. The system may comprise a device that computes reception correlation data for a received signal, and a beamformer that is adapted to determine transmission weighting coefficients to be applied to a return signal based on the difference between the reception correlation data and the fixed beam weighting coefficients associated with at least one of the plurality of fixed beams.

A downlink beamforming apparatus and a transmission apparatus including the same includes a subcarrier based user identifier for dividing subcarriers according to users, a beamforming weight buffer for storing first beamforming weights for the subcarriers by each of transmitting antennas, an interpolator for outputting second beamforming weights for each transmitting antenna by interpolating the first beamforming weights, and a signal reproducer for reproducing the signal for each transmitting antenna. Subcarriers are allocated to the signal by each user; and a complex multiplier multiplies the signal for each transmitting antenna by the second beamforming weights.

The application relates to the technical field of wireless communication, and provides a communication method between a terminal and the terminal, network side equipment and the terminal. The method comprises the following steps: the network side equipment distributes time frequency resource for transmitting uplink information and sidechain information for the terminal; the terminal transmits theuplink information for performing uplink beam training to the network side equipment at the same moment in the time frequency resource range on the time frequency resource, and transmits the sidechaininformation for performing sidechain beam training to another terminal. Through the scheme provided by the embodiment of the invention, the terminal can perform the beamforming training of the sidechain without additionally using the new time frequency resource based on the traditional uplink and downlink beamforming training procedure.

The present invention provides a system and method for transmit beamforming in a Frequency Division Duplex communication system. A first step (600) includes correcting for differences between transceiver receive and transmit responses within a base station. A next step (604) obtaining a beamforming weight of a phase antenna array on an uplink. A next step (606) transforming the uplink beamforming weight a downlink beamforming weight by applying a phase correction that is a function of wavelength at the uplink and downlink frequencies and distance between antenna elements.

An apparatus having: 1) a database for storing R active wireless terminal records, each of the R active wireless terminal records containing: a) an active orthogonal code and b) corresponding downlink beamforming coefficients used to communicate with one of the wireless access terminals; and 2) a controller associated with the database that receives a notification that a new wireless access terminal is accessing the base station and, in response to the notification, compares each of the R active wireless terminal records to new downlink beamforming coefficients associated with the new wireless access terminal. The controller determines at least one active wireless terminal record containing corresponding downlink beamforming coefficients that have the least correlation with the new downlink beamforming coefficients.

The invention discloses a method for controlling the power of the HSDPA system, which aims at the HS-SICH and includes the steps of: real-time monitoring the corresponding relationship between the HS-SCCH as well as the HS-SICH and UE, and obtaining a time parameter of the corresponding relationship between the channel and the UE; a first stage, which is the stage from the first HS-SCCH subframe transmitted from the base station to the generation of the power control instruction by utilizing the first HS-SICH subframe fed back by the UE, wherein, the power control instruction can be set to be up or down randomly or alternately; a second stage, which is the stage from the generation of the power control instruction by utilizing the first HS-SICH subframe fed back by the UE to the last HS-SCCH subframe transmitted for the UE, wherein, the power control instruction can be set by utilizing the power control parameters obtained from the calculation of the HS-SICH subframe; the base station transmits the HS-SCCH subframe carrying the power control instruction to the UE. The invention also discloses a power control method aiming at the HS-SCCH, a base station and a down beam shaping proposal.

The invention discloses a method, a device and a system for beamforming a smart antenna. The method comprises the following steps: calculating a downlink beamforming weight vector UR according to a spatial covariance matrix R corresponding to a channel impulse response matrix H acquired in advance; calculating a downlink beamforming weight vector URm according to a spatial covariance matrix Rm corresponding to a channel impulse response matrix Hm determined after the channel impulse response matrix H is rearranged in a conjugated way; determining a corrected downlink beamforming weight vectorby taking the downlink beamforming weight vector UR and downlink beamforming weight vector URm as correct parameters; utilizing a downlink beamforming weight vector U to weight each antenna amplitudephase so as to realize downlink beamforming of a user. The method can reduce multipath signal correlation under the condition of not increasing calculation quantity and not reducing array antenna aperture and can still realize better downlink beamforming even if strong correlative signal exists.

The disclosure relates to a method (13) for enabling accurate measurement results for a communication device (16). The method comprises sending (102), by a serving node (12) serving the communication device and to a neighbour network node (13), a request for measuring on the uplink reference signals from the communication device; the serving and neighbour nodes receiving (103), from the communication device, uplink reference signals; the serving and the neighbour nodes obtaining (104) downlink beamforming weights based on the received uplink reference signals; the serving and the neighbour nodes transmitting (105), to the communication device, specific downlink reference signals adapted for the communication device by using the downlink beamforming weights; the UE transmitting (107) a downlink measurement report to the serving node; the serving node taking a mobility decision based on the UE report (108). The disclosure also relates to the corresponding network nodes, computer programs and computer program products.

Techniques are provided herein to generate beamforming weight vectors for transmissions to be made from a first wireless communication device, e.g., a base station, to a second wireless communication device, e.g., a client device. The first device has a plurality of antennas and receives uplink transmissions from the second device, each uplink transmission comprising a group of frequency subcarriers. The first device computes channel information from the received uplink transmission and computes one or more trigonometric waveforms determined to approximate the channel information. One or more downlink beamforming weight vectors are computed at any given frequency subcarrier (thus in any frequency subband) by interpolation using the one or more trigonometric waveforms.