# US 2014/0192762 A1 · Methods and apparatuses for channel measurement and feedback of multi-dimensional antenna array > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192762 A1 - Document ID: US20140192762A1 - Status: Published application - Kind: A1 - Application number: 14/239,052 - Filed: 2012-08-14 - Published: 2014-07-10 - Earliest claimed: 2011-08-15 - Assignees: Alcatel Lucent - Inventors: Dong Li; Lu Wu; Hongwei Yang - Web page: https://patentgrep.com/patent/US20140192762A1 ## CPC - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04L 25/03929: {with layer mapping, e.g. codeword-to layer design (for space-time coding H04L1/0618)} - H04W 24/08: Testing, {supervising or monitoring} using real traffic - H04L 1/0026: {Transmission of channel quality indication} - H04L 25/0204: {of multiple channels} - H04W 28/06: Optimizing {the usage of the radio link}, e.g. header compression, information sizing {, discarding information (system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365)} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Embodiments of the present invention generally relate to methods and apparatuses for the channel measurement and feedback of a multi-dimensional antenna array. Specifically, according to embodiments of the present invention, the primary inventive idea is to allow a base station equipped with a multi-dimensional antenna array to configure more than one class of CSI-RS, wherein each class of CSI-RS is for use in a channel measurement at the UE for a different dimension of the multi-dimensional antenna array. The base station then transmits the generated configuration information to the UE so that the UE may perform channel measurement specific to different dimensions, for example, by selecting different codebooks for the channel measurement for different dimensions. In this way, it is possible to increase the channel measurement precision of the multi-dimensional antenna array, reduce the measurement feedback overhead and improve the system performance. ## Claims ### Claim 1 A method for enabling channel measurement and feedback of a multi-dimensional antenna array in a wireless communication system, the method comprising: generating configuration information for at least two classes of channel state information reference signals (CSI-RS), wherein each of the at least two classes of CSI-RS is for use in a channel measurement at a user equipment for a different dimension of the multi-dimensional antenna array; and transmitting the configuration information to the user equipment, so that the user equipment receives the at least two classes of CSI-RS according to the configuration information. ### Claim 2 (canceled) ### Claim 3 (depends on 1) The method according to claim 1, wherein the configuration information indicates that the at least two classes of CSI-RS are simultaneously transmitted to the user equipment in a same sub-frame. ### Claim 4 (depends on 1) The method according to claim 1, wherein the configuration information indicates that the at least two classes of CSI-RS are alternately transmitted to the user equipment in different sub-frames. ### Claim 5 (depends on 4) The method according to claim 4, wherein the configuration information indicates that the at least two classes of CSI-RS are transmitted to the user equipment in different sub-frames with equal cycles. ### Claim 6 (depends on 4) The method according to claim 4, wherein the configuration information indicates that the at least two classes of CSI-RS are transmitted to the user equipment in different sub-frames with different cycles. ### Claim 7 (canceled) ### Claim 8 (canceled) ### Claim 9 A method for enabling channel measurement and feedback of a multi-dimensional antenna array in a wireless communication system, the method comprising: receiving, from a base station, configuration information for at least two classes of channel state information reference signals (CSI-RS), wherein each of the at least two classes of CSI-RS is for use in a channel measurement for a different dimension of the multi-dimensional antenna array; and receiving the at least two classes of CSI-RS from the base station according to the configuration information, for performing and feeding back channel measurements for different dimensions of the multi-dimensional antenna array. ### Claim 10 (depends on 9) The method according to claim 9, wherein the receiving the at least two classes of CSI-RS from the base station according to the configuration information comprises: simultaneously receiving the at least two classes of CSI-RS in a same sub-frame from the base station according to the configuration information. ### Claim 11 (depends on 9) The method according to claim 9, wherein the receiving the at least two classes of CSI-RS from the base station according to the configuration information comprises: alternately receiving the at least two classes of CSI-RS in different sub-frames from the base station according to the configuration information. ### Claim 12 (depends on 11) The method according to claim 11, wherein the alternately receiving the at least two classes of CSI-RS in different sub-frames from the base station according to the configuration information comprises: receiving from the base station the at least two classes of CSI-RS in different sub-frames with equal cycles according to the configuration information. ### Claim 13 (depends on 11) The method according to claim 11, wherein the alternately receiving the at least two classes of CSI-RS in different sub-frames from the base station according to the configuration information comprises: receiving from the base station the at least two classes of CSI-RS in different sub-frames with different cycles according to the configuration information. ### Claim 14 (canceled) ### Claim 15 (canceled) ### Claim 16 (depends on 9) The method according to claim 9, wherein the channel measurements for different dimensions of the multi-dimensional antenna array are performed by selecting different codebooks. ### Claim 17 (depends on 16) The method according to claim 16, wherein codebooks used for the channel measurements for different dimensions of the multi-dimensional antenna array are derived from a common codebook according to respective codeword subset restrictions. ### Claim 18 (depends on 17) The method according to claim 17, wherein a codebook used for a channel measurement for a vertical dimension of the multi-dimensional antenna array is a codebook subset from the common codebook, the codebook subset conforming to a Discrete Fourier Transform (DFT) codebook. ### Claim 19 An apparatus for enabling channel measurement and feedback of a multi-dimensional antenna array in a wireless communication system, the apparatus comprising: configuration information generating means for generating configuration information for at least two classes of channel state information reference signals (CSI-RS), wherein each of the at least two classes of CSI-RS is for use in a channel measurement at a user equipment for a different dimension of the multi-dimensional antenna array; and configuration information transmitting means for transmitting the configuration information to the user equipment, so that the user equipment receives the at least two classes of CSI-RS according to the configuration information. ### Claim at position 20 20-26. (canceled) ### Claim 27 An apparatus for enabling channel measurement and feedback of a multi-dimensional antenna array in a wireless communication system, the apparatus comprising: configuration information receiving means for receiving from a base station configuration information for at least two classes of channel state information reference signals (CSI-RS), wherein each of the at least two classes of CSI-RS is for use in a channel measurement for a different dimension of the multi-dimensional antenna array; and reference signal receiving means for receiving the at least two classes of CSI-RS from the base station according to the configuration information, for performing and feeding back channel measurements for different dimensions of the multi-dimensional antenna array. ### Claim at position 22 28-36. (canceled)