491 results about "Channel state information feedback" patented technology

Methods for a User Equipment (UE) to transmit Channel Quality Index (CQI) feedback information, and an indicator in feedback information, to an evolved Node B (eNB) in a wireless communication system, and apparatuses therefore, are provided. A method for a UE to transmit CQI feedback information to eNB in a wireless communication system, includes obtaining one or more Transmission Points Configurations for Coordinated MultiPoint (CoMP) (TPCCs), each TPCC including a unique combination of one or more cells in a CoMP measurement set, estimating a channel for one or more cells in the CoMP measurement set, computing a CQI for each of at least one of the one or more TPCCs, each CQI being computed using one or more estimated channels that correspond to the combination of one or more cells included in a corresponding TPCC, generating CQI feedback information based on the one or more CQIs, and transmitting the CQI feedback information.

In a multi-carrier communication system where a base station performs resource allocating power allocation and adaptive modulation processes for a mobile station by using CSI (Channel State Information) received from the mobile station, a CSI feedback method in accordance with the present invention determines a CSI transmission mode according to an amount of data traffic on a reverse link, encodes CSI for subcarriers into one CSI codeword according to the determined CSI transmission mode, and transmits the CSI codeword to the base station. Since the CSI is adaptively transmitted according to the amount of the data traffic of the reverse link, it can effectively use resources of the reverse link.

A Channel State Information (CSI) feedback method and apparatus is provided for transmitting, at a base station, the CSIs for plural transmit antennas with a limited amount resource and receiving, at a mobile station, the CSIs efficiently in a massive Multiple Input Multiple Output (MIMO) system operating in the Frequency Division Duplex (FDD) mode.

The invention provides a method for feeding back channel state information (CSI), comprising the following steps of: receiving a CSI reference signal CSI-RS (CSI-Reference Signal) measurement set configuration signaling from a base station, and the CSI-RS measurement set configuration signaling comprising indications which aim at a CSI-RS measurement set configured by a user device; measuring the CSI-RS in the CSI-RS measurement set according to the indications of the CSI-RS measurement set to obtain metrics corresponding to the format of the CSI-RS in the CSI-RS measurement set; obtaining a CSI-RS report set which is selected from the CSI-RS measurement set according to the metrics; determining a CSI feedback resource corresponding to the format of the CSI-RS in the CSI-RS report set; and using the determined CSI feedback resource to feed back the CSI corresponding to the format of the CSI-RS in the CSI-RS report set to the base station. As well, the invention also provides the corresponding user device and the base station.

A method of transmitting information over a feed back channel of a communication system that has multiple antenna systems is provided. Long term channel condition information is obtained from received measured and/or calculated channel parameter values. The obtained long term channel condition information is arranged in a particular manner and transmitted over a defined time period during which the long term channel condition information varies relatively slowly. Because the long term information remains relatively constant for one or more defined time periods, the amount of bandwidth needed to communicate this value is small because it need only be communicated occasionally. Thus only a small bandwidth needs to be allocated for transmitting this long term information.

Disclosed are a determination method and device for the instruction signaling of a channel measurement pilot frequency and a CSI feedback method and device. The determination method for the instruction signaling of a channel measurement pilot frequency comprises: a base station sends to a terminal a downlink control signaling comprising the transmission resource configuration information of a non-periodic channel state information reference signal (CSI-RS), said information being used to determine the position of the non-periodic CSI-RS, and the non-periodic CSI-RS being used to instruct the terminal to perform channel measurement. The present invention determines the non-periodic CSI-RS using the transmission resource configuration information of the non-periodic CSI-RS, and uses the non-periodic CSI-RS to perform channel measurement, thereby solving the problem in the prior art that periodic CSI-RS transmissions have high cost and waste resources, conserving resources, and reducing transmission costs.

This invention relates to a method and a system for realizing adaptive down-link in the multi-user multi-in/out system including the following steps: UE measure the channel state of a down-link and feeds it to the base station, which distributes sub-carriers to the UE based on the state information and informs the distribution result to the corresponding UE, which estimates the channel quality of the down channel based on the sub-carrier and feeds back the information to the base station, which selects corresponding emission antennas and modulates each selected antenna adaptively and selects the code mode to distribute and control the emission power.

A method for wireless communication is provided which includes receiving first and second signals transmitted from first and second antennas, respectively, determining a time offset between the first and second antennas based on the first and second signals, and reporting information regarding the time offset, including information regarding the time offset as being above or below a predetermined threshold. Another method for wireless communication is provided which includes generating channel state information feedback based on an assumption that the time offset is being compensated at a transmitter side. Yet another method for wireless communication is provided which includes receiving information regarding a time offset between multiple transmit antennas, including information regarding the time offset as being above or below a predetermined threshold, and adapting downlink transmissions to account for the time offset.

The present invention relates to the technical field of wireless communications. Disclosed in an embodiment of the present invention are a channel state information (CSI) feedback trigger, feedback method and device for enabling a terminal to conduct non-periodic CSI feedback in an expanded non-periodic CSI feedback mode supporting COMP transmission. In the present invention, a base station determines the expanded non-periodic CSI feedback mode adopted by the terminal to conduct the non-periodic CSI feedback, and notifies the terminal the determined feedback mode via signaling; the base station triggers the terminal via signaling to conduct the non-periodic CSI feedback in the expanded non-periodic CSI feedback mode; and the terminal conducts the non-periodic CSI feedback in the expanded non-periodic CSI feedback mode. The present invention enables the terminal to conduct the non-periodic CSI feedback in the expanded non-periodic CSI feedback mode.

A method, an apparatus, and a computer program product for wireless communication are provided in which downlink transmission modes in a wireless network are semi-statically configured for a mobile terminal in multiple-input multiple-output (MIMO) operation. The apparatus provides multiple precoding matrix indicators (PMIs) for a plurality of ranks. The provision of multiple PMIs by the apparatus enables balanced performance among different ranks and avoids less than optimal performance observed when the apparatus provides only a single rank and PMI that are generally not optimal for all transmissions. Feedback configuration information received by an apparatus defines a plurality of channel state information feedback instances conditioned on an admissible rank value. Rank indicators (RIs) and PMIs corresponding to the feedback instances are determined and feedback is provided for the channel state information feedback instances.

The specification and drawings present a new method, apparatus and software related product for using non-codebook based CSI feedback (e.g., in LTE wireless systems) using selection by a UE of one or more of the plurality of logical antenna ports based on a predefined procedure (e.g., SNR or SINR measurement), but without selecting any codeword (precoder) by the UE. This allows not to involve any standardization of codebooks for precoding due to reliance on an alternative CSI feedback framework which does not rely on standardized codebooks. The exemplary embodiments described herein aim at development of 3GPP LTE Release-12.

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 invention discloses a feedback method and a device in a coordinated multiple point (CoMP) transmission system. The embodiment of the invention adopts corresponding feedback modes which are set based on different transmission modes or member carriers, and configures different measurement sets for a terminal according to the different feedback modes, so that after the feedback mode is determined, the terminal can determine the corresponding measurement sets according to the feedback mode and feed the channel state information measured by the measurement set back to a base station, thereby avoiding the problem in the prior art that no matter which feedback mode is configured for the terminal, the terminal needs to take the same cell sets as measurement objects so as to feed all or partial measured channel state information back to the base station. Compared with the prior art, the invention has the advantages of greatly reducing feedback signaling expenses and being favor for improving the frequency spectrum efficiency of the system.

The invention discloses a method and equipment for generating a codebook and sending and feeding back information. The method for sending the information comprises the following steps: after the codebook is generated, receiving signals containing codebook index information and extracting the codebook index information; according to the codebook index information, selecting corresponding precoding matrixes from the codebook or subsets of the codebook; precoding data to be sent according to the precoding matrixes; and sending the precoded signals to a receiving end. The method of feeding back channel status information comprises the following steps: receiving information sent by a sending end; estimating channel information on the basis of the received information; selecting the corresponding precoding matrixes from the codebook or the subsets of the codebook according to the channel information,; and sending signals containing codebook index information corresponding to the selected precoding matrixes. By the invention, dual-precoding matrix index feedback can be supported, the quantization accuracy of small-interval dual-polarization array channels can be improved, and the quantization accuracy of small-interval linear array channels can be enhanced.

The invention proposes a method for channel state information feedback of a large-scale multi-input-multi-output (MIMO) system. In one embodiment, the method includes the following steps: a piece of UE detects a plurality of downlink reference signal ports and feeds back indexes of part of reference signal ports which are better in channel quality so as to assist in uplink reception precoding operations. Through use of the method and device, a problem of CSI feedback in a Massive MIMO system is solved and through support of uplink reception precoding, a problem of pilot-frequency pollution is prevented and moreover, a calculation complexity needed by uplink channel estimation is reduced significantly and at the same time, compatability with an existing system is maintained to the largest degree.

A spatial channel state information (CSI) feedback technique is incorporated into multiple-input multiple-output mobile communications technologies. Spatial channel state information is measured at receiving equipment and then decomposed into components. The components are then quantized using codebook(s) and fed back as multiple indices to transmitting equipment.

The invention discloses a channel state information transmission method and a channel state information transmission device. The method comprises that: user equipment determines channel state information based on a channel estimation value; and the user equipment feeds the channel state information back by utilizing a cyclic reporting mode supporting coordinated multiple point (CoMP) transmission. By the method and the device, channel state information feedback supporting the CoMP transmission can be realized.

An embodiment of the present invention relates to a wireless communication system, wherein said wireless communication system uses multiple input and multiple output antenna (MIMO) on both transmission and receiving ends.

The invention relates to the wireless communication field and discloses a state information feedback method of channels and a wireless transceiver; in the invention, at least two codebooks generated according to different rules are used. A receiving end is used for selecting a pre-coding matrix combination that is most suitable for the present states of the channels and sending the pre-coding matrix combination with limited bit to a sending end, therefore, the pre-coding treating performance can be improved without adding the amount of feedback information, and storing space needed for storing the codebooks can be saved. A main codebook and an assistant codebook can be used; the assistant codebook can be regarded as a disturbance added on the basis of the main codebook; wherein, the main codebook can be generated and chosen according to the prior technical scheme, and the assistant codebook can be generated based on Fourier matrix or extended rotation matrix.

The embodiment of the invention discloses a channel state information feedback method, channel state information feedback equipment, a channel state information receiving method and channel state information receiving equipment. By the technical scheme provided by the embodiment of the invention, user equipment feeds channel state information back to network side equipment in a periodic reporting mode supporting coordinated multiple point (CoMP) transmission, wherein a corresponding periodic reporting mode comprises a reporting type used for feeding the rank indication (RI) of a main transmission point back, a reporting type used for feeding a channel quality indicator (CQI) and a precoding matrix indicator (PMI) of the main transmission point back, and/or a reporting type used for feeding the CQI and PMI of a non-main transmission point back, and/or a reporting type used for feeding the CQI and PMI, based on the hypothesis of RI=1, of the main transmission point back. Therefore, various CoMP transmission schemes can be supported.

Improving jitter performance of time delay of C-MCPFS proportion fairness algorithm in multicarrier system, the disclosed method accomplishes allocation of frequency resources. The method includes following five operation steps: (1) preparative step for partitioning resources, and setting up initialization parameters; (2) step for feeding back information of channel state; (3) step for allocating RB resources; (4) data transmission step; (5) step for estimating time delay of data packet. Considering channel state of user and practical transfer rate of traffic in scheduling process, the method keeps good proportion fairness performance. Two points of innovation are: introducing time delay control mechanism, and estimating time delay of data packet. The method provides smooth data rate for transmission layer, and keeps efficiency and fairness of C-MCPFS algorithm.

The invention discloses an aperiodically channel state information feedback method and device to feed back channel state information corresponding to E-PDCCHs (enhanced-physical downlink control channel) aperiodically so as to better schedule corresponding terminals according to the channel state information of the E-PDCCHs. The aperiodically channel state information feedback method comprises the steps of: determining the channel state information to be fed back according to the configured channel state information feedback mode, wherein the channel state information to be fed back comprises the channel state information of PDSCHs (physical downlink shared channel) and/or the channel state information of the E-PDCCHs; and reporting the determined channel state information to be fed back.