60results about "Spatial transmit diversity" patented technology

Adaptive modulation techniques for multi-antenna transmissions with partial channel knowledge are described. Initially, a transmitter is described that includes a two-dimensional beamformer where coded data streams are power loaded and transmitted along two orthogonal basis beams. The transmitter optimally adjusts the basis beams, the power allocation between two beams, and the signal constellation. A partial CSI model for orthogonal frequency division multiplexed (OFDM) transmissions over multi-input multi-output (MIMO) frequency selective fading channels is then described. In particular, an adaptive MIMO-OFDM transmitter is described in which the adaptive two-dimensional coder-beamformer is applied on each OFDM subcarrier, along with an adaptive power and bit loading scheme across the OFDM subcarriers.

A computer implemented method and apparatus utilizing a multi-diversity synchronization technique for improving time synchronization in wireless applications, such as TDMA applications is disclosed. The multi-diversity synchronization technique utilizes cross-correlations between multiple diverse received signals to determine relative offsets between the signals. The signals are then time aligned. An absolute synchronization word location is determined using the time aligned signals and is used along with the relative offsets to determine respective synchronization word locations for each received signal in an accurate, efficient and improved manner.

The invention discloses a communication method and device. The method comprises the steps that a network device sends configuration information to a terminal device; the terminal device determines a channel state information (CSI) measurement behavior and/or CSI feedback related information, wherein the channel state information (CSI) measurement behavior and/or the CSI feedback related information is related to the configuration information; and the terminal device performs CSI measurement to acquire at least one piece of CSI according to the CSI measurement behavior and/or the CSI feedback related information and the configuration information, and sends all or part in the at least one piece of CSI to the network device. According to the method, for a scene in support of various transmission modes, the terminal device can measure the CSI and feeds back the measured CSI to the network device.

A radio frequency transceiver for a wireless local area network (LAN) may have two or more antennae. An active antenna that delivers a data-bearing signal having a signal quality at least as good as any of the antennae may be selected based upon measurements of the signal quality during a preamble field of data frames having a substantially longer preamble field than other data frames.

A MIMO transmitter including an interleaving system for parsing encoded bits to a plurality of spatial streams and a plurality of interleavers to interleave bits for spatial streams such that at least a first spatial stream uses a first stream interleaver that interleaves with a pattern distinct from a second stream interleaver interleaving for a second spatial stream.

An S/P converting section (101) converts input transmission signals A1, A2, B1, B2, . . . , K1, K2 to parallelized data, separated in individual transmission lines. Spreading sections (102, 103) spread the respective data under control of a spread control section (107). Adding sections (104-1, 104-2) multiplex spread data. Transmitting sections (105-1, 105-2) provide radio transmission processing to the multiplexed signals, and transmit the data via antennas (106-1, 106-2) by radio. The spread control section (107) controls the spreading methods in the spreading sections (102, 103) based on channel quality. This makes it possible to improve error rate characteristics of the received signal and as maintain spectrum efficiency when varying data is transmitted from multiple antennas.

A method and apparatus is disclosed herein for scheduling, load balancing and/or pilot assignment in MIMD cellular deployments (e.g., reciprority-based MIMO cellular deployments). In one embodiment, the method comprises receiving, by the central controller from at least one AP, for at least one user terminal, a size of a user set and user rate information indicative of a rate that can be provided to the user terminal when served in a group of one or more user terminals; and determining, by the central controller, based on user rate information and the user set size, an allocation of AP resources among the user terminals for the at least one

The invention relates to a low earth orbit satellite smart antenna receiving system and method. The receiving system is composed of an array antenna consisting of N element antennas, N paths of digital receivers and a self-adaptive anti-interference smart antenna digital circuit; the smart antenna receiving system adopts a nulling anti-interference digital multi-beam forming technology and a multi-objective angle estimation technology, which can form a capture beam and a tracking beam at the same time; the tracking beam pointing is adjusted in real time according to a user angle estimation result or satellite orbit characteristics; and the interference nulling positions of the capture and tracking beams are adjusted in real time according to an interference angle estimation result or the satellite orbit characteristics. The low earth orbit satellite smart antenna receiving system provided by the invention can quickly locate the interference and the target, and form a nulling direction pattern in the airspace to suppress the interference of dynamic changes, so that the low earth orbit satellite smart antenna receiving system is especially suitable for a smart antenna system for low earth orbit satellite earth communication.

A method, provided by the present disclosure, of transmitting a reference signal by means of a base station in a wireless communication system using a plurality of antenna ports comprises the steps of: mapping wireless resources, for transmitting a reference signal, to a plurality of antenna ports for transmitting the reference signal; and using the wireless resources and transmitting the reference signal to a terminal through the mapped antenna ports. The step of mapping to the antenna ports is characterized by being executed on the basis of a combination of a first mapping pattern between the wireless resources and the antenna ports and a second mapping pattern between the wireless resources and the antenna ports.

Besides normal states of receiving and transmitting channel, the disclosed receiver and transmitter in radio frequency also possesses calibration states. In time of calibrating transmitting channel, the method lets two sets of receiver and transmitter of calibration work at calibration state of receiving channel to receive a calibration signal; and other receivers and transmitters work at normal state to transmit calibration signals. The method obtains each two times of test data of each transmitting channel. In time of calibrating receiving channel, the method lets two sets of receiver and transmitter of calibration work at calibration state of transmitting channel in sequence to transmit calibration signal; and other receivers and transmitters work at normal state to receive calibration signals. The method obtains each two times of tested data of each receiving channel. Based on the said two times of tested data, the method calibrates receiving and transmitting channels.

Certain aspects relate to methods and apparatus for wireless communication. The apparatus generally includes a first interface configured to output one first frame for transmission to solicit CSI feedback from each of one or more first wireless nodes associated with a first BSS and from each of one or more second wireless nodes associated with a second BSS, a second interface configured to obtain the CSI feedback solicited from the first and second wireless nodes, and a processing system configured to generate data frames for the first wireless nodes based on the CSI feedback solicited from the first wireless nodes, and one or more nulling frames based on the CSI feedback solicited from the second wireless nodes. The first interface is configured to simultaneously output the data frames for beamformed transmission to the first wireless nodes, and the nulling frames for beamformed transmission to the second wireless nodes.

The invention requests for protecting a method for safely optimizing a physical layer in a multi-relay cognitive radio network, and relates to the technical field of cognitive wireless communication systems. For a scene that multiple mutually colluded wiretapping nodes exist in the multi-relay cognitive radio network, the invention provides a safe transmission scheme of a zero-space artificial noise and amplified forwarding (AF) relay beam forming physical layer. Firstly, a system is modelled, and designed into a secrecy rate maximization problem; secondly, due to introduction of a slack variable, the fact that the secrecy rate maximization problem can be converted into the tight and slack problem is proved theoretically; furthermore, joint optimization solution of a relay beam forming weighting matrix and an artificial noise covariance matrix is carried out by utilizing a semi-definite programming method; and finally, due to MATLAB simulative verification and analysis, the secrecy rate of the system can be increased to a great degree.

The invention proposes a wireless communication apparatus and its method. The wireless communication apparatus comprises: multiple antennas, a multiple-antenna signal processing module, a RF signal processing module and a baseband processing module. The multiple-antenna signal processing module is designed to combine multiple RF signals received from the multiple antennas into a single RF signal. The RF signal processing module is designed to convert the combined single RF signal into a single baseband signal. The baseband processing module is designed to perform baseband processing on the single baseband signal. This wireless communication apparatus realizes a multi-antenna system by simply inserting a multiple-antenna signal processing module into a typical singleantenna system. Both the RF signal processing module and baseband processing module of existing single-antenna system remain unchanged. Therefore, the redesign process is greatly simplified, which results in remarkable reduction of design difficulty and implementation cost.

Phase and amplitude deviations, which are generated, for example, by cables connecting an array antenna of a CDMA base station and the base station, are calibrated in the baseband.

The base station comprises: an antenna apparatus 1; couplers 2; an RF unit 3 that converts a receive signal to a baseband signal, converts a transmit signal to a radio frequency, and performs power control; an A/D converter 4 for converting a receive signal to a digital signal; a receive beam form unit 6 that multiplies the receive signal by semi-fixed weight; a despreader 7 for this signal input; a time-space demodulator 8 for demodulating user data; a despreader 9 for probe signal; a space modulator 14 for user data; a spreader 13 for user signal; a channel combiner 12; a Tx calibrater 11 for controlling calibration of a signal; a D/A converter 10; a unit 16 for calculation of correlation matrix for generating a probe signal used for controlling an Rx calibration system and a TX calibration system; a spreader 17 for probe signal; a power control unit 18; a D/A converter 19; an RF unit 20 for probe signal; an A/D converter 21 for signal from the couplers 2; and a despreader 22.

Provided are a method for reporting channel state information of a terminal in a wireless communication system and a device using the method. A terminal receives at least one or more A-CSI request message that triggers aperiodic CSI reports for a plurality of CSI processes of a first cell, and as a response to the at least one or more A-CSI request message, updates at least one of the plurality of CSI processes that were triggered, wherein, if a CSI process capability is defined as the maximum number of CSI processes that the terminal may operate for a specific cell, and if the CSI process capability for the first cell is less than the number of the triggered aperiodic CSI reports, and the CSI process capability for a second cell is more than the number of aperiodic CSI reports triggered for the second cell, the residual CSI process capability for the second cell is used for updating the CSI process for the first cell.

The embodiment of the invention discloses an LTE receiving channel delay correction method, a device and a base station with the device. The method comprises the steps of receiving uplink sounding signals of multiple users with multiple antennas; selecting a user from multiple users as a set user, and according to the uplink sounding signal of the set user acquiring the power delay spectrum of the set user in each receiving channel; according to the power delay spectrum of each receiving channel respectively acquiring the delay value of each receiving channel; and according to the delay value of each receiving channel respectively carrying out delay adjustment on each receiving channel. In this embodiment, the characteristic that the LTE system needs to employ the sounding signal of the user and a power delay spectrum estimation algorithm to compute the PDP estimation so as to obtain the power delay spectrum is employed, and then the delay adjustment value is obtained according to the power delay spectrum, thus the delay correction of the radio frequency receiving channel in the base station is realized.

The invention discloses an adaptive multiple input multiple output method and system for aviation communication. The adaptive multiple input multiple output method for the aviation communication comprises the following steps of: 1, establishing a three-dimensional multiple input multiple output channel model; 2, computing optimal channel capacity; 3, acquiring a distance between an airplane and a ground antenna array and a direction angle of the airplane relative to the ground antenna array; 4, computing a distance dr between every two adjacent antennae in a virtual receiving antenna array on an airplane body according to the optimal channel capacity, the distance and the direction angle by using an adaptive minimum mean square error interpolation algorithm; and 5, computing a distance dt between every two adjacent antennae in a virtual transmitting antenna array on the airplane body according to the optimal channel capacity, the distance and the direction angle by using an adaptive delay algorithm. According to the adaptive multiple input multiple output method and system disclosed by the embodiment of the invention for the aviation communication, maximum system capacity can be provided according to the position of the airplane in real time.

A method for determining weight factors of antenna beams, the method comprising using at least one directional antenna beam implemented with an antenna array to establish a radio link, forming a radio cell with the antenna beam, dividing the radio cell into at least two different cells by dividing the antenna beam, selecting weight factors of antenna elements of the antenna array such that the antenna element specific sums of weight factors of a radio cell formed with the antenna array and corresponding weight factors of at least one, second radio cell formed with the same antenna array are at least substantially equal within predetermined limits in order to achieve a predetermined power balance between different antenna elements.

The invention provides a directional modulation signal design method based on spatial Fourier transformation. The method comprises the following steps of establishing desired phase wave beam spatial coverage functions in ideal conditions relative to different communication models; and acquiring a phased array element weighted value according to the spatial Fourier transformation pair relation among phase wave beams and the array element weighted value of a phased array in a directional modulation signal transmitter to achieve a directional modulation signal design in different communication models. By using the directional modulation signals designed by the method, valid users can normally demodulate received directional modulation signals through common digital signal receivers. As to wiretappers in undesirable directions, their wiretapping receivers cannot demodulate useful communication information from received signals due to the relative phase relationship distortion of constellation points in a received signal constellation diagram. The invention provides a safe transmission method for transmitting communication information in wireless channels.

The invention discloses a technical project which uses multiple antennas and realizes synchronization in a multi-antenna environment. The invention distributes an antenna address code to each antenna in a base station and denotes the antenna address code of the used antenna to a mobile external. According to the antenna address code denoted by the base station, the mobile terminal demodulates and obtains the data on the antenna distributed by the base station. In the technical project of the invention, because each antenna in the multiple antennas has respective antenna address code, the mobile terminal can distinguish each antenna and get the corresponding data from the antenna used by the terminal in addition to making the use of the space gain brought by the multiple antennas by denoting the antenna address code of the antenna used by the mobile terminal to the mobile terminal. At the same time, the requirement that consumers or operations are measured off on the antennas can be satisfied.

The invention provides a method and device for shaping wave beams. The method includes the steps of obtaining position information of users to be served by a current time slot, determining a handling capacity function of the total handling capacity of the users relative to downward inclination angle combinations according to the position information of the users, estimating the downward inclination angle combination by which the maximum value of the handling capacity function is obtained with the DIRECT algorithm, and then adjusting the downward inclination angles of the two wave beams according to the downward inclination angle combination obtained through calculation. By means of the technical scheme, the system hanging capacity can be improved.

A system having a multi-layer (multi-stream) multiple-input-multiple-output (MIMO) receiving system, having a MIMO baseband module and a radio distribution network (RDN) connected to the MIMO receiving system. The RDN has two or more beamformers that are fed by two or more antennas, so that a total number of antennas in the system are greater than the number of branches of the MIMO baseband module. Each of the beamformers combines RF signals coming from the antennas. The system further implements an antenna routing module that swaps antennas between different beamformers according to one or more qualitative indicators derived from the baseband module, thus increasing the probability of grouping antennas that have lower conflicts between best phases of different layers' transmitted signals. The system increases the range of antenna selection beyond the set of antennas available for each beamformer.