41 results about "Multiuser communication" patented technology

The present invention relates to improved multiple access communications. In one form, the invention relates to an improved signal processing method and apparatus for an iterative method of determining the reception of a signal in a multi user packet based wireless OFDM (Orthogonal Frequency Division Multiplexing) communication system. In other forms the present invention provides recursive filtering for joint iterative decoding in a variety of systems and functions such as linear multiple access channel decoders, iterative equalisation, iterative joint channel estimation and detection / decoding, iterative space-time processing, iterative multi user interference cancellation and iterative demodulation. In one particular form the present invention provides an iterative decoding circuit for a wireless multiuser communications receiver comprising a first signal processing means for receiving at least one received signal, said first signal processing means comprising at least two linear iterative filters such that the first linear iterative filter provides an estimate of a selected received signal to an estimated signal output and a second linear iterative filter provides estimates of at least one other received signal, delayed by one iteration cycle, to an input of said first linear iterative filter, a second signal processing means for receiving the estimated signal output of the first linear iterative filter and providing a further received signal estimate to the input of the first signal processing means in a succeeding iteration cycle of the decoding circuit.

Certain embodiments of the invention may be found in a method and system for an improved user group selection scheme with finite-rate channel state information feedback for frequency division duplex (FDD) multiuser multiple-input-multiple-output (MIMO) downlink transmission. Aspects of the method may include selecting, from a plurality of users in a FDD multiuser communication system, a first user having a channel gain that is greater than a channel gain corresponding to a remaining portion of the plurality of users. A second user may be selected from the remaining portion of the plurality of users, based on a channel gain of the second user and orthogonality of the second user's channel direction with respect to the first user. The selected second user may have a channel gain that is greater than a channel gain corresponding to the remaining portion of the plurality of users.

Certain embodiments of the invention may be found in a method and system for an improved user group selection scheme with finite-rate channel state information feedback for frequency division duplex (FDD) multiuser multiple-input-multiple-output (MIMO) downlink transmission. Aspects of the method may include selecting, from a plurality of users in a FDD multiuser communication system, a first user having a channel gain that is greater than a channel gain corresponding to a remaining portion of the plurality of users. A second user may be selected from the remaining portion of the plurality of users, based on a channel gain of the second user and orthogonality of the second user's channel direction with respect to the first user. The selected second user may have a channel gain that is greater than a channel gain corresponding to the remaining portion of the plurality of users.

The present invention relates to improved multiple access communications. In one form, the invention relates to an improved signal processing method and apparatus for an iterative method of determining the reception of a signal in a multi user packet based wireless OFDM (Orthogonal Frequency Division Multiplexing) communication system. In other forms the present invention provides recursive filtering for joint iterative decoding in a variety of systems and functions such as linear multiple access channel decoders, iterative equalisation, iterative joint channel estimation and detection / decoding, iterative space-time processing, iterative multi user interference cancellation and iterative demodulation. In one particular form the present invention provides an iterative decoding circuit for a wireless multiuser communications receiver comprising a first signal processing means for receiving at least one received signal, said first signal processing means comprising at least two linear iterative filters such that the first linear iterative filter provides an estimate of a selected received signal to an estimated signal output and a second linear iterative filter provides estimates of at least one other received signal, delayed by one iteration cycle, to an input of said first linear iterative filter, a second signal processing means for receiving the estimated signal output of the first linear iterative filter and providing a further received signal estimate to the input of the first signal processing means in a succeeding iteration cycle of the decoding circuit.

Multiuser communication systems are presented. The disclosed systems include a database of communication room objects and a communication room management server. The management server can instantiate one or more of the room objects as a persistent meeting room through which users can share multimedia content. The meeting room can remain persistent independent of user participation. The system can further include a display manager capable of configuring a display of a user device into multiple display regions where each display region can render one or more types of multimedia room content. A user can, with a single gesture, rearrange the display regions under governance of the display manager.

The invention relates to a multi user communication wire disturbing testing method and device that carries preset orthotropic spread spectrum to the send end on each line, taking cross talk testing to xDSL line according to the received signal vector at receiving end to effectively recognize the cross talk resource, cross talk extent and phase. The invention could also realize the measuring for cross talk value between the lines. The invention supplies basic data for dynamic frequency spectrum managing and DSLAM system optimizing.

A cooperative code-enhanced multiuser communications system having a receiver for resolving user ambiguity in a received composite signal by using convolutional encoder state machine properties to analyze strings of bit sums and separate out individual user data. The receiver comprises a signal sampler which converts a received composite signal to a digital data. A single point cluster mapper determines a closest pseudo-constellation point, and the pseudo-constellation point is formed with the aid of power and timing control in the transmitters. A bit sum look-up table maps symbol points to bit sums. A deterministic loop tests for bit sum cases where symbols can be determined immediately. A guess loop tests the bit sum after the deterministic loop test and performs guesses until all bits are decided. The bit sum is provided to a multiuser convolutional decoder to decide all user data streams.

The invention discloses a method, a system and a device used for multiuser communication and a method used to release event status, wherein the method used for multiuser communication comprises the following steps that: an application server, after receiving a multiuser communication request carrying the group condition of the current multiuser communication, controls the current multiuser communication according to the group condition of the current multiuser communication obtained from the request. The method, the system and the device provided by the embodiment of the invention can set the group condition of multiuser communication and limits the participants of the multiuser communication through the group condition. The method used to release event status provided by the invention comprises the following steps that: an application server, after receiving a release message carrying the event status and the authorization information of resource, controls the subscription right of the event status of the resource according to the authorization information. Moreover, the method can realize subscription limitation of the event status.

The invention discloses a multiuser mobile communication terminal, wherein various user identification cards share a wireless transmitting and receiving unit and a baseband processing unit; the multiuser mobile communication terminal classifies the various user identification cards according to networks to which the user identification cards belong, and carries out simultaneous standby or communication with the networks by multiuser wireless resource management, multiuser mobile management and multiuser communication management. When calling, the multiuser mobile communication terminal sends position information and a priority sequence table of expected called numbers to the other side, and selects the optimal communication route and mobile phone card according to the various user identification cards, and positions and time of the communication of two sides, so that a user can not only select a mobile phone card to call out according to the self will, but also select a mobile phone card to be called according to the self will. The multiuser mobile communication terminal has functions of calling position identification and called position identification, reduces cost, volume, weight and power consumption, and is convenient to realize multicard mobile phones or multi-mode multicard mobile phones.

The invention provides a general method for realizing group communication on a webpage and belongs to the technical field of network technology. The method comprises that: a user opens the webpage; a flash is loaded on the webpage; a webpage program acquires all IDs of a group, in which the user joins; all IDs together with the user name of the user are sent to a socket server; and the socket server stores all IDs, the user name and socket thread numbers in a hash table. When the user sends a message to the group, and the socket server searches the hash table for the socket thread numbers corresponding to the user names of users corresponding to the IDs in the group and sends the message to users corresponding to the IDs in the group through socket threads corresponding to the socket thread numbers. The method can realize webpage group and multiuser communication and is a feasible method for instant multiuser communication and group chat on the webpage.

A method for beamforming by a transmission device in a multiantenna multiuser communication system. The method includes grouping codebook indexes included in a codebook into codebook index combinations, and calculating a sum of transmission rate for each of the codebook index combinations; selecting a codebook index combination with a maximum sum of transmission rate as an optimal codebook index combination; and transmitting a codebook index corresponding to a particular reception device among codebook indexes included in the optimal codebook index combination, to the particular reception device.

A computer implemented method is provided for implementing user centric advertising and multiuser communication. The method includes providing a communication interface between advertiser devices, user devices and publisher devices, receiving advertiser preferences from the user devices, matching the preferences with advertisements from the advertiser devices and displaying the matched advertisements on a portal. The method also includes providing functionality for conducting two way communication between select user devices and advertiser devices, and conducting e-commerce transactions. The method also including a social exchange platform with functionality for user to user communication.

A communication method and system facing multiple users in immediate communication, relate to an electrinic communication technic. When an immediate communication client terminal receives messages, the received messages from a plurality or senders are displayed in a same message window of the immediate communication client terminal, the displayed messages are carried with marks of the corresponding senders sending the messages. When the client terminal sends messages, at first a receiver is determined, the determined receiver is a current receiver for the immediate communication client terminal sending the messages, and a corresponding receiver mark is displayed in a message input window of the immediate communication client terminal; the immediate communication client terminal performs visible marking on the messages carried with the sender marks in the message window, reflects that the sender is determined as the current receiver of the client sending messages, the invention realizes simultaneous immediate communication between a same message window or message input window and a plurality of client terminals, convenient communication and display, strong practicability and operability.

A code-enhanced, multi-user detection, Reduced Algorithm Receiver in a multiuser communication system reduces the signal processing requirements by limiting the number of searches between consecutive symbol cycles using information from an encoder state diagram. The Receiver makes use of a convolutional encoder's state machine properties to mark possible transitions as invalid based on the current state of the multiple users'encoders, thus removing them from the search tree. The Reduced Algorithm Receiver comprises a Signal Sampler for converting a single composite waveform signal (Rx) to digitized composite signal (DRx), a Parameter Estimator for determining waveform characteristics of each of the multiple users, a Memory for storing predetermined training sequences for each of the users, a Next State Predictor that reduces the amount of symbols being checked during a current cycle, a Waveform Approximator that receives the user waveform characteristics data and a set of possible bits from the next state predictor and attempts to simulate modulation of the individual user signal, a Demodulator for comparing the set of possible composite waveforms (~Tx) from the Waveforms Approximator to the digitized composite waveforms (DRx) and determining the best match waveform, and a Convolutional Decoder for receiving the best match symbols and decoding them for each of the users.

A system and method are provided for facilitating multiuser communication in a Virtual Reality [VR] environment (10). The multiuser communication may involve a VR device configured to render the VR environment (10) to a local user (5), a plurality of remote communication devices which enable respective remote users to participate in the multiuser communication, and a camera (120) configured to record video of the local user (5) and to transmit the video as part of communication data to the plurality of remote communication devices for remote rendering of the video. The system and method may detect communication (15), or an intent of communication, from the local user (5) to at least one of the remote users so as to identify a target user and thereby a target communication device of the target user, and differently generate the communication data for a) the target communication device, and b) other remote communication devices of other remote users, to signal whether a particular remote communication device is addressed by the communication, e.g., using a graphical indicator (50).

The invention relates to the technical field of cooperative multipoint communication, in particular to a multi-cell zero-forcing interference suppression method. According to the multi-cell zero-forcing interference suppression method, a singular value decomposition method in the prior art is combined with rectangular projection transformation of a matrix, so that an optimal pre-coding matrix among various base stations and object users of the base stations is obtained, and the interference in a multiuser communication system is suppressed. Compared with a technical scheme based on beam forming, the multi-cell zero-forcing interference suppression method has the advantages of simple algorithm and easiness in realization; compared with a technical scheme based on singular value decomposition, the multi-cell zero-forcing interference suppression method increases the velocity of the system communication, and achieves very high communication quality even in an area with a low signal-to-noise ratio.

A code-enhanced, multi-user detection, Reduced Algorithm Receiver in a multiuser communication system reduces the signal processing requirements by limiting the number of searches between consecutive symbol cycles using information from an encoder state diagram. The Receiver makes use of a convolutional encoder's state machine properties to mark possible transitions as invalid based on the current state of the multiple users'encoders, thus removing them from the search tree. The Reduced Algorithm Receiver comprises a Signal Sampler for converting a single composite waveform signal (Rx) to digitized composite signal (DRx), a Parameter Estimator for determining waveform characteristics of each of the multiple users, a Memory for storing predetermined training sequences for each of the users, a Next State Predictor that reduces the amount of symbols being checked during a current cycle, a Waveform Approximator that receives the user waveform characteristics data and a set of possible bits from the next state predictor and attempts to simulate modulation of the individual user signal, a Demodulator for comparing the set of possible composite waveforms (˜Tx) from the Waveforms Approximator to the digitized composite waveforms (DRx) and determining the best match waveform, and a Convolutional Decoder for receiving the best match symbols and decoding them for each of the users.

This invention relates to a distribution network multiuser communication method which tests multiuser vector channel occupying state in the network by real-time, describes the three-phase circuit into multiuser vector channels to be resolved to scalar channels to be distributed in bit according to the real-time tested channel occupation state. The method equalizes the multiuser distribution network to multiuser communication vector channels to be resolved and get equivalent point-to-point channel model to realize dynamic bit distribution so as to realize dynamic bit distribution and multiuser high efficient communication.

A cooperative code-enhanced multiuser communications system having a receiver for resolving user ambiguity in a received composite signal by using convolutional encoder state machine properties to analyze strings of bit sums and separate out individual user data. The receiver comprises a signal sampler which converts a received composite signal to a digital data. A single point cluster mapper determines a closest pseudo-constellation point, and the pseudo-constellation point is formed with the aid of power and timing control in the transmitters. A bit sum look-up table maps symbol points to bit sums. A deterministic loop tests for bit sum cases where symbols can be determined immediately. A guess loop tests the bit sum after the deterministic loop test and performs guesses until all bits are decided. The bit sum is provided to a multiuser convolutional decoder to decide all user data streams.

An adaptive receiver for multiple access communication, illustratively UWB multiple access communication, is provided. One embodiment of a detector is derived based on the finding that an symmetric alpha-stable model is more suitable for modeling the MAI in multiuser UWB systems than existing models. A myriad filter detector works better than all the known receiver structures proposed for statistical MAI cancellation. An intuitive expression for the tuning parameter K is provided which worked well in the examples considered.

The invention provides a pseudo-random phase sequence for time-frequency estimation, and the phase sequence is characterized in that the phase sequence has a linear time-frequency characteristic and has good self-correlation and cross-correlation characteristics, so a group of pilot frequency symbols which are not correlated pairwise can be constructed by utilizing the pseudo-random phase sequence, and are used for a multi-user communication system. Furthermore, the invention provides a method for constructing pilot symbols by using the pseudo-random phase sequence pairs, which comprises parallel pilot symbols and serial pilot symbols. Furthermore, the invention provides a method for performing time frequency estimation by adopting frequency domain correlation and time domain circumference correlation based on the pilot frequency symbol, and the key technology of pilot frequency of a multi-user communication system is solved.

The invention discloses a multi-user communication method based on a geographic position and a spatial range and relates to the technical field of data communication. By the adoption of the multi-user communication method based on the geographic position and the spatial range, provided by the embodiment of the invention, after a user sends information, the information can be spread in a certain peripheral space and in a time range, and users in the range can receive the information; the distance permission of information spreading can also be set, and the spreading distance of a message can be controlled by utilizing the permission. Thus, large-scale interactive communication can be carried out for users between neighbors, in the same street community and in the same office building or garden, and a notice, an announcement and an advertisement can be given in a region; a better user experience is brought.

Techniques for compensating for frequency mismatch between transmitters and receivers of a multiuser communication system having a plurality of users are disclosed. In particular, the mismatch of carrier frequency estimates are estimated and compensated for each user of the system. This is accomplished without increasing the training overhead of the system. Symbol phase drift and offset is computed by estimating phase error profile parameters (e.g., slope and offset). The disclosed techniques may be used to correct for symbol rotation in any one decision region, or in neighboring decision regions.

A method for beamforming by a transmission device in a multiantenna multiuser communication system. The method includes grouping codebook indexes included in a codebook into codebook index combinations, and calculating a sum of transmission rate for each of the codebook index combinations; selecting a codebook index combination with a maximum sum of transmission rate as an optimal codebook index combination; and transmitting a codebook index corresponding to a particular reception device among codebook indexes included in the optimal codebook index combination, to the particular reception device.

Systems and methods are provided for generating and rendering an enhanced audiovisual recording of a user, which may be used for multiuser communication, e.g., in Virtual Reality. Such an enhanced recording may be generated by determining a face orientation of the user in the audiovisual recording, and generating orientation data specifying an orientation which represents said determined face orientation. During rendering, the audio data may be rendered based on the orientation data, namely by rendering the audio data as a spatial audio source having a spatial direction which is congruent withthe face orientation of the user in a visual representation of the user. Accordingly, the spatial direction of the voice of the user may better match the user's face direction in the user's visual representation.

It is characterized in that the information to be modulated in the phase difference, that belongs to the set of information possible according to the number of phases of the constellation to be used, an injective application between this set and the set of information possible to be modulated corresponding to the constellation with the maximum number of phases is carried out. This permits bits to be changed by a carrier without sending a new phase reference, to maximize the number of symbols of information within the frame and to implement a modulator and a low complexity modulator and demodulator. Applicable in multiuser digital communication that requires bits to be changed by the carrier of the constellation in one single data frame, in order to adapt to the maximum transmission capacity of the channel, to follow the amplitude variations thereof and to allow information to be transmitted from one to several users.

The invention discloses a method, a system and a device used for multiuser communication and a method used to release event status, wherein the method used for multiuser communication comprises the following steps that: an application server, after receiving a multiuser communication request carrying the group condition of the current multiuser communication, controls the current multiuser communication according to the group condition of the current multiuser communication obtained from the request. The method, the system and the device provided by the embodiment of the invention can set thegroup condition of multiuser communication and limits the participants of the multiuser communication through the group condition. The method used to release event status provided by the invention comprises the following steps that: an application server, after receiving a release message carrying the event status and the authorization information of resource, controls the subscription right of the event status of the resource according to the authorization information. Moreover, the method can realize subscription limitation of the event status.

An operation method of a first communication node in a wireless communication network comprises the steps of: transmitting, to a plurality of communication nodes, a first frame comprising configuration information of a data transmission interval comprising at least one frame transmission interval; and receiving second data frame(s) from at least one of the communication nodes, among the plurality of communication nodes, during the data transmission interval. The first frame may comprise: identifier(s) indicating the plurality of communication nodes; and information for configuring a network allocation vector (NAV) for communication nodes excluding the plurality of communication nodes.