Alcatel Lucent

Di Lv

Hongwei Yang

Yang Song

Lu Wu

Jinhui Chen

Hao Liu

Dong Li

JinHui Chen

Dong Sheng Li

The present invention proposes a technical solution of codebook design which is suitable for antennas configured in a uniform circular array. Respective codewords in the designed codebooks have constant modulus, respective columns being orthogonal to each other and nested property. Based on the designed codebook, the invention further provides a method of determining a codeword in a base station of a MIMO communication system, the base station being configured with Nantennas in a uniform circular array, wherein the method comprises the steps of receiving codeword index information from a user equipment; and determining a target codeword corresponding to the codeword index information from a set of codebooks according to the codeword index information,wherein the set of codebooks comprises Ncodebooks corresponding respectively to respective ranks and the Ncodebooks are determined based upon a codebook of rank 1 and a N&#xd7;NHadamard matrix, the first column of the Hadamard matrix is all 1 or all &#x2212;1. As compared with the existing Rel-10 codebook, the codebooks designed according to the invention can reduce a feedback overhead and improve the average spectrum efficiency of a cell and spectrum efficiency of a user at the edge of the cell.

Method of generating codebook of uniform circular array and acquiring codeword from the codebook

A method and device for generating and feeding back high rank adaptive codebook in multiple input multiple output system are disclosed in the embodiments of the invention. The method for generating high rank adaptive codebook includes: using different levels of a long time channel correlation matrix to transform different row vectors in high rank basic codebook, so as to aim at the directions of different eigenvectors of the long time channel correlation matrix; and using the transformed row vectors to construct the high rank adaptive codebook. The method of the invention has well system performance gain and no any additional feedback cost.

Methods and apparatuses for generating and feeding back high rank adaptive codebook in multiple input multiple output system

Methods and apparatuses for information feedback and precoding have been provided. A method for processing communication data at a user equipment in a wireless communication system may comprise: deriving a spatial correlation matrix R of multiple transmit antennas of a base station based on an obtained downlink channel transmission matrix H; transforming a precoding codebook F according to the spatial correlation matrix R; selecting a precoding matrix Fbased on the transformed precoding codebook; and feeding back information about the spatial correlation matrix R and information about the selected precoding matrix Fto the base station. A method for data precoding at a base station in a wireless communication system may comprise: obtaining, from a user equipment, information about a spatial correlation matrix R of multiple transmit antennas of the base station and information about a precoding matrix Fselected by the user equipment; determining a desired precoding matrix Fbased on the obtained information and a precoding codebook; and precoding downlink data to be transmitted to the user equipment with the desired precoding matrix F.

Method and apparatus for information feedback and precoding

In order to improve the performance of the precoding scheme for closely-spaced cross-polarized CLA antennas, the invention proposes a new precoding codebook and precoding matrix. The invention also proposes a method for determining precoding matrix based on the new precoding codebook, and corresponding method and device for communicating by using this precoding matrix. The precoding codebook and matrix proposed in the invention has better performance.

Method of determining precoding matrix and corresponding communication methods and devices

The present invention provides a precoding method for a cross-polarized antenna array, the cross-polarized antenna array comprising a first group of coplanar polarized antennas and a second group of coplanar polarized antennas, the method comprising the following steps: generating, for at least one layer of data stream, a feedback codebook comprising a plurality of codewords; receiving a selection of the codeword in the feedback codebook; determining a corresponding codeword from the feedback codebook according to the received selection; generating a precoding matrix based on the determined codeword to precode the at least one layer of data stream; wherein each codeword in the feedback codebook comprises a first coefficient portion corresponding to a first group of coplanar polarized antennas and a second coefficient portion corresponding to the second group of coplanar polarized antennas, and there is a complex scaling relation between the coefficients in the first coefficient portion and the second coefficient portion corresponding to the same layer of data stream. Correspondingly, the present invention further provides a precoder for a cross-polarized antenna array.

Precoding method and precoder for cross-polarized antenna array

A method for determining precoding matrix for the sub-band precoding in a transmitter with M transmitting antennas. The method includes determining an optimized first matrix Waccording to wideband and/or long-term channel properties, multiplying the optimized first matrix W, with each second matrix W, in a second codebook, to obtain a plurality of candidate precoding matrices, the second matrix Wcorresponds to frequency-selective and/or short-term channel properties; selecting an optimized one from the plurality of candidate preceding matrices for precoding the data to be transmitted, according to a frequency selection and/or a short-term channel state information. The amount of DFT beams may be increased to improve the spatial resolution; a diagonal matrix is involved in the first matrix W; and phase adjustment is involved in the second matrix W, so as to guarantee the adjusted phase is evenly distributed among the whole phase space.

Method for determining precoding matrix and corresponding communication methods and devices

The present invention provides a method and device for obtaining precoding matrix. A network apparatus comprises a plurality of groups of cross-polarized linear array antennas. The method comprises: obtaining first channel indicating information indicating a first code word; obtaining second channel indicating information indicating a second code word; determining the precoding matrix, according to the first channel indicating information and the second channel indicating information, the first code word and/or the second code word comprises phase shifts and/or amplitude differences among the plurality of groups of cross-polarized linear array antennas. Since the first code word and the second code word for determining the precoding matrix by the network apparatus comprise phase shifts and amplitude differences among cross-polarized linear array antennas, the phase shifts and amplitude differences among cross-polarized linear array antennas are considered when the network apparatus sends downlink data according to the precoding matrix, so as to be able to improve the receiving quality of the sent data, thereby improving the system performance effectively.

Method and device for obtaining precoding matrix

The present invention provides a method for feeding back a correlation matrix in a multi-input multi-output system, comprising: constructing codebooks for the correlation matrix based on a conjugation nature of the correlation matrix and based on a predetermined relationship between diagonal elements and off-diagonal elements in the correlation matrix; selecting a codeword from the constructed codebook; and feeding back a corresponding index of the selected codeword in the codebook. Through the present invention, the throughput of the multi-input multi-output system can be enhanced, while reducing the encoder complexity or transfer load.

Method and apparatus for feeding back and constructing correlation matrix in multi-input multi-output systems

The present invention provides a method and system for channel status information feedback based on a hierarchical codebook, the method comprising steps of: generating a hierarchical codebook; configuring the generated hierarchical codebook to a transmit end and a receive end, respectively; and feeding back channel state information from the receive end to the transmit end based on the hierarchical codebook, wherein the step of generating a hierarchical codebook further comprises the following steps: i) dividing each level of codeword in a to-be-generated codebook into a plurality of segments based on a basic codebook; ii) a module configured to generate each level of codeword in a first stage, wherein the each level of codeword is selected from the basic codebook; and iii) generating each level of codeword in other stages, wherein the each level of codeword is selected a pre-provided training sample matrix. And the feeding back the channel status information from the receiving end to the transmitting end based on the hierarchical codebook further comprises using a first bit and a second bit of the feedback bits to represent a signaling for performing tree search to the hierarchical codebook.

Channel status information feedback

A method and apparatus for processing downlink communication and a corresponding assisting method and apparatus are provided. According to an embodiment, a method for assisting a base station in processing downlink communication in a user equipment includes: estimating a downlink channel between the base station and the user equipment; determining a spatial correlation matrix between the base station and the user equipment according to the result of estimating the downlink channel; determining at least one pre-coding vector among a plurality of pre-stored pre-coding vectors based upon the spatial correlation matrix; and notifying the base station about the determined at least one pre-coding vector and spatial correlation matrix. The downlink communication processing disclosed herein improves the performance of a system, improves the average throughput and the throughput of an edge user of the multi-user MIMO system and has a wider applicability scope than the original codebook and feedback mechanism.

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Shanghai, China

Di Lv