# US 2014/0154970 A1 · Method and Device for Controlling Relay Transmission Based on Non-Reproduction Relay Mode > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0154970 A1 - Document ID: US20140154970A1 - Status: Published application - Kind: A1 - Application number: 14/130,297 - Filed: 2011-06-30 - Published: 2014-06-05 - Earliest claimed: 2011-06-30 - Assignees: Beijing University of Posts and Telecommunications - Inventors: Hang Long; Kan Zheng; Fangxiang Wang - Web page: https://patentgrep.com/patent/US20140154970A1 ## CPC - H04B 7/15: Active relay systems - H04B 7/204: Multiple access - H04B: TRANSMISSION ## Abstract The present invention discloses a method and device for controlling a relay transmission based on non-reproduction relay mode, comprising: each relay node within a service area to which a source node belongs obtaining channel status information between itself and the source node and channel status information between itself and a destination node, calculating required channel information for relay selection and feeding the required channel information back to the source node; after receiving channel information sent by the relay nodes, the source node, according to the channel information, selecting from the relay nodes a group of relay nodes with greatest feedback values in the channel information to forward information and selecting a group of relay nodes with second greatest feedback values to send interference information, selected relay nodes transmitting information to the destination node in cooperation with the source node in non-reproduction relay mode. By means of the method for controlling a relay transmission based on non-reproduction relay mode of the present invention, while greatly reducing network signaling load and computation complexity, the system secrecy capacity is ensured, the performance-to-cost ratio is high, and stronger applicability is achieved. ## Claims ### Claim 1 A method for controlling a relay transmission based on non-reproduction relay mode, characterized by comprising: each relay node within a service area to which a source node belongs obtaining channel status information between itself and the source node and channel status information between itself and a destination node, calculating required channel information for relay selection and feeding the required channel information back to the source node; after receiving channel information sent by the relay nodes, the source node, according to the channel information, selecting from the relay nodes a group of relay nodes with greatest feedback values in the channel information to forward information and selecting a group of relay nodes with second greatest feedback values to send interference information, selected relay nodes transmitting information to the destination node in cooperation with the source node in non-reproduction relay mode. ### Claim 2 (depends on 1) The method according to claim 1, characterized in that, the step of each relay node obtaining channel status information between itself and the source node and channel status information between itself and a destination node, calculating required channel information for relay selection and feeding the required channel information back to the source node comprises: each relay node, after measuring channel coefficients between itself and the source node and between itself and the destination node, calculating absolute values of the channel coefficients between itself and the source node and between itself and the destination node, comparing the absolute values to obtain a smaller one and feeding the smaller value back to the source node. ### Claim 3 (depends on 1) The method according to claim 1, characterized by further comprising: received information yRi of the ith relay node selected to forward information being: yRi=√{square root over (PS)}hSRixS+nRi, where information, to be transmitted from the source node to the destination node is xS, the ith relay node is selected to forward information, hSRi, is a channel between the source node and the ith relay node, PS is transmitting power of the source node, nRi is a noise value of the ith relay node; if a forward coefficient of the ith relay node is βi, then forwarded information xRi of the ith relay node is: xRi=βiyRi where βi−2=PS|hSRi|2+σ2, σ2 is noise power of the ith relay node; the jth relay node selected to send interference information sends interference information, received information yD of the destination node is: yD=√{square root over (PR)}hRiDxRi+nD, where nD is a noise value of the destination node; where received information yE of an eavesdropping node is: yE=√{square root over (PR)}hRiExRi+√{square root over (PR)}hRjExRj+nE; where information that is forwarded by the ith relay node to the destination node and the eavesdropping node is xRi, interference information that is sent by the jth relay node to the destination node and the eavesdropping node is xRj, hRiD is a channel between the ith relay node and the destination node, hRiE is a channel between, the ith relay node and the eavesdropping node, and PR is transmitting power of the relay nodes within a service area to which the source node belongs. ### Claim 4 (depends on 1) The method according to claim 1, characterized, by, further comprising: a step of determining relay nodes within the service area to which the source node belongs, wherein the source node determines the relay nodes within its service area by signaling. ### Claim 5 (depends on 1) The method according to claim 1, characterized by, further comprising: a relay node that is not selected among the relay nodes being kept on standby status, the relay node periodically updating the channel status information for next relay selection. ### Claim 6 A device for controlling a relay transmission, characterized by comprising: an information obtaining unit for obtaining channel status information between each relay node within a service area to which a source node belongs and the source node and channel status information between the each relay node and a destination node; a calculating unit for calculating required channel information for relay selection according to the obtained channel status information; and a relay node selecting unit for, according to the calculated channel information, selecting from the relay nodes a group of relay nodes with greatest feedback values in the channel information to forward information and selecting a group of relay nodes with second greatest feedback values to send interference information. ### Claim 7 (depends on 6) The device according to claim 6, characterized in that, the information obtaining unit obtains the channel status information by measuring channel coefficients between each relay node and the source node and between each node and the destination node; the calculating unit calculates the required channel information for relay selection by calculating absolute values of the channel coefficients between each relay node and the source node and between each relay node and the destination node and then comparing the absolute values to obtain a smaller one. ### Claim 8 (depends on 6) The device according to claim 6, characterized by, further comprising: a relay node determining unit for determining relay nodes within the service area to which the source node belongs. ### Claim 9 (depends on 6) The device according to claim 6, characterized in that, the relay node determining unit is further for using selected relay nodes to transmit information to the destination node in cooperation with the source node in the non-reproduction relay mode. ### Claim 10 (depends on 9) The device according to claim 9, characterized in that, received information yRi of the ith relay node that is selected by the relay node selecting unit to forward information is: yRi=√{square root over (PS)}hSRixS+nRi, where information to be transmitted from the source node to the destination node is xS, the ith relay node is selected to forward information, hSRi is a channel between the source node and the ith relay node, PS is transmitting power of the source node, nRi is a noise value of the ith relay node; if a forward coefficient of the ith relay node is βi then forwarded information xRi of the ith relay node is: xRi=βiyRi, where βi−2=PS|hSRi|2+nD, is noise power of the ith relay node; the jth relay node selected by the relay node selecting unit to send interference information sends interference information, received information yD of the destination node is: yD=√{square root over (PR)}hRiDxRi+nD, where nD is a noise value of the destination node; where received information yE of an eavesdropping node is: yE=√{square root over (PR)}hRiExRi+√{square root over (PR)}hRjExRj+nE, where information that is forwarded by the ith relay node to the destination node and the eavesdropping node is xRi, interference information that is sent by the jth relay node to the destination node and the eavesdropping node is xRj, hRiD is a channel between the ith relay node and the destination node, hRiE is a channel between the ith relay node and the eavesdropping node, and PR is transmitting power of the relay nodes within a service area to which the source node belongs.