# US 8,787,475 B2 · Method of designing codebook for network multiple input multiple output communication system and method of using the codebook > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,475 B2 - Document ID: US8787475B2 - Status: Granted - Kind: B2 - Application number: 13/861,581 - Filed: 2013-04-12 - Published: 2013-08-29 - Granted: 2014-07-22 - Earliest claimed: 2008-09-25 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Yongxing Zhou; Hua Li; Sung Jin Kim - Web page: https://patentgrep.com/patent/US8787475B2 ## CPC - H04B 7/0456: Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting - H04B 7/0478: {Special codebook structures directed to feedback optimisation} - H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection} - H04B 7/0465: {taking power constraints at power amplifier or emission constraints, e.g. constant modulus, into account} - H04B 7/0469: {taking special antenna structures, e.g. cross polarized antennas into account} - H04B: TRANSMISSION ## Abstract Provided herein is a method of designing a network codebook that may be shared by a plurality of base stations. Also provided herein is a feedback method of a terminal using the network codebook. The network codebook design method may design the network codebook by processing a pre-defined first codebook based on large scale fading of the base stations. The terminal may more effectively feed back a preferred matrix indicator with respect to the network codebook. ## Claims ### Claim 1 A feedback method of a terminal using a network codebook, the method comprising: feeding back to a first base station a preferred matrix indicator of the terminal with respect to a codebook of the first base station, and a channel quality indicator between the first base station and the terminal; and feeding back to a second base station a preferred matrix indicator of the terminal with respect to a codebook of the second base station, and a preferred matrix indicator of the terminal with respect to the network codebook, wherein the network codebook is shared by the first base station and the second base station. ### Claim 2 (depends on 1) The method of claim 1, wherein: where a third base station sharing the network codebook exists, the feeding back to the second base station comprises feeding back to the second base station a portion of the preferred matrix indicator of the terminal with respect to the network codebook, and the method further comprises feeding back, to the third base station, a portion of the preferred matrix indicator of the terminal with respect to the network codebook. ### Claim 3 (depends on 1) The method of claim 1, wherein the network codebook is designed by performing: designing a second codebook based on information associated with large scale fading from the first base station and the second base station to the terminal, and a pre-defined first codebook; and designing the network codebook from the second codebook, based on a concatenated codebook that is designed from codebooks of the first base station and the second base station. ### Claim 4 (depends on 1) A non-transitory computer-readable medium comprising a program for instructing a computer to perform the method of claim 1. ### Claim 5 (depends on 1) The method of claim 1, wherein the preferred matrix indicator (PMI) is associated with a channel between the first base station and the terminal. ### Claim 6 (depends on 1) The method of claim 1, wherein the preferred matrix indicator (PMI) is associated with a channel between the second base station and the terminal. ### Claim 7 (depends on 1) The method of claim 1, wherein the terminal feeds back channel status information to the first base station and the second base station. ### Claim 8 A communication method of a terminal in a multiple input multiple output (MIMO) communication system comprising: generating a network codebook based on information associated with large scale fading from a plurality of base stations to a terminal and a concatenated codebook that is generated from codebooks of the base stations; calculating a preferred matrix indicator of the terminal with respect to the network codebook; feeding back to at least one of base station the preferred matrix indicator of the terminal with respect to the network codebook. ### Claim 9 (depends on 8) The method of claim 8, further comprising: feeding back to at least one of base station a preferred matrix indicator of the terminal with respect to each of the codebooks. ### Claim 10 (depends on 8) The method of claim 8, wherein the generating of the network codebook comprises: generating a second codebook based on the information associated with large scale fading and a pre-defined first codebook; and generating the network codebook from the second codebook, based on the concatenated codebook. ### Claim 11 (depends on 8) The communication method of claim 8, wherein feeding back to at least one of base station the preferred matrix indicator of the terminal with respect to the network codebook comprises: dividing the preferred matrix indicator of the terminal with respect to the network codebook; and feeding back to at least two base stations the divided preferred matrix indicator. ### Claim 12 (depends on 8) A non-transitory computer-readable medium comprising a program for instructing a computer to perform the method of claim 8. ### Claim 13 A communication method of a terminal in a multiple input multiple output (MIMO) communication system comprising: generating a network codebook based on information associated with channels from base stations to a terminal and a concatenated codebook that is generated from codebooks of the base stations; calculating a preferred matrix indicator of the terminal with respect to the network codebook; and feeding back to at least one base station the preferred matrix indicator of the terminal with respect to the network codebook. ### Claim 14 A terminal in a multiple input multiple output (MIMO) communication system comprising: a network codebook design apparatus configured to generate a network codebook based on information associated with large scale fading from a plurality of base stations to a terminal and a concatenated codebook that is generated from codebooks of the base stations, wherein the terminal is configured to calculate a preferred matrix indicator of the terminal with respect to the network codebook, and to feed back to at least one of base station the preferred matrix indicator of the terminal with respect to the network codebook. ### Claim 15 (depends on 14) The terminal of claim 14, further configured to feed back to at least one of base station a preferred matrix indicator of the terminal with respect to each of the codebooks. ### Claim 16 (depends on 14) The terminal of claim 14, wherein the network codebook design apparatus comprises: a second codebook design unit configured to generate a second codebook based on the information associated with large scale fading and a pre-defined first codebook; and a network codebook design unit configured to generate the network codebook from the second codebook, based on the concatenated codebook. ### Claim 17 (depends on 14) The terminal of claim 14, configured to feed back to at least one of base station the preferred matrix indicator of the terminal with respect to the network codebook by: dividing the preferred matrix indicator of the terminal with respect to the network codebook; and feeding back to at least two base stations the divided preferred matrix indicator. ### Claim 18 A terminal using a network codebook, comprising: a processor; and a memory, wherein one or more programs are stored in the memory and configured to be executed by the processor, the one or more programs including: instructions for feeding back to a first base station a preferred matrix indicator of the terminal with respect to a codebook of the first base station, and a channel quality indicator between the first base station and the terminal; and instructions for feeding back to a second base station a preferred matrix indicator of the terminal with respect to a codebook of the second base station, and a preferred matrix indicator of the terminal with respect to the network codebook, wherein the network codebook is shared by the first base station and the second base station. ### Claim 19 (depends on 18) The terminal of claim 18, wherein, where a third base station sharing the network codebook exists, the one or more programs further including: instructions for feeding back to the second base station comprises feeding back to the second base station a portion of the preferred matrix indicator of the terminal with respect to the network codebook; and instructions for feeding back, to the third base station, a portion of the preferred matrix indicator of the terminal with respect to the network codebook. ### Claim 20 (depends on 18) The terminal of claim 18, wherein the one or more programs further including: instructions for generating a second codebook based on information associated with large scale fading from the first base station and the second base station to the terminal, and a pre-defined first codebook; and Instructions for generating the network codebook from the second codebook, based on a concatenated codebook that is generated from codebooks of the first base station and the second base station.