41 results about "Multiuser communication" patented technology

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.

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 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.

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.

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.