# US 7,613,977 B2 · Retransmission control method and transmitter in wireless communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,613,977 B2 - Document ID: US7613977B2 - Status: Granted - Kind: B2 - Application number: 11/377,497 - Filed: 2006-03-16 - Published: 2007-05-31 - Granted: 2009-11-03 - Earliest claimed: 2005-11-29 - Assignees: Fujitsu Limited - Inventors: Kotaro Shiizaki; Daisuke Jitsukawa; Kenji Suda; Hiroyuki Seki - Web page: https://patentgrep.com/patent/US7613977B2 ## CPC - H04L 1/0083: {Formatting with frames or packets; Protocol or part of protocol for error control} - H04L 1/1671: {the supervisory signal being transmitted together with control information} - H04L 1/1867: Arrangements specially adapted for the transmitter end - H04L 1/1812: Hybrid protocols; Hybrid automatic repeat request [HARQ] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In a wireless communication system, in which a frame comprising data and control information necessary for reception processing of the data is transmitted from a transmitter, and in which, when a reception failure is notified by a receiver, the frame that failed to be received is retransmitted, the control information is classified into first control information that can be different for a new frame transmission and a repeat frame transmission and second control information that is the same for the new frame transmission and the repeat frame transmission, information indicating whether or not the receiver has correctly received the control information and data is acquired, and when the control information has been correctly received, control is conducted so that the second control information is not transmitted during the repeat frame transmission. ## Claims ### Claim 1 A retransmission control method in a wireless communication system in which a frame comprising data and control information necessary for reception processing of the data is transmitted from a transmitter and, when a reception failure is notified by a receiver, the frame that failed to be received is retransmitted, the method comprising the steps of: classifying the control information into first control information that can be different for a new frame transmission and a repeat frame transmission and second control information that is the same for the new frame transmission and the repeat frame transmission; acquiring information indicating whether or not the receiver has correctly received the control information consisting of the first and second control information and data; and executing, when the control information has been correctly received, control so that the second control information is not transmitted during the repeat frame transmission. ### Claim 2 (depends on 1) The retransmission control method according to claim 1, further comprising a step of transmitting the first and second control information during the repeat frame transmission if the control information has not been received correctly. ### Claim 3 (depends on 1) The retransmission control method according to claim 1, further comprising a step of additionally providing the frame with an identification information for indentifying whether or not the second control information is contained. ### Claim 4 (depends on 1) The retransmission control method according to claim 1, further comprising a step of inserting a pilot, or the first control information, or the data into an empty space that appears because the second control information is not transmitted, and executing transmission in duplicate thereof. ### Claim 5 (depends on 3) The retransmission control method according to claim 3, comprising the steps of checking whether each of the control information consisting of the first and second control information and data has been correctly received each time the is received, and conveying the check results to the transmitter; determining whether the second control information is contained in the frame based on the identification information contained in the frame; when the second control information is contained in the frame, executing the reception control of the data based on the received first and second control information, and storing the second control information; and executing the reception control of the data based on the received first control information and the second control information that has been stored if the second control information is not contained in the frame. ### Claim 6 (depends on 1) The retransmission control method according to claim 1, further comprising a step of time-division multiplexing, or frequency multiplexing, or code multiplexing, in the data frame, the data, the first and second control information and the pilot. ### Claim 7 A transmitter for a wireless communication system which transmits a frame comprising data and control information necessary for reception processing of the data and, when a reception failure is notified by a receiver, retransmits the frame that failed to be received, the transmitter comprising: a control information generation unit for generating first control information that can be different for a new frame transmission and a repeat frame transmission and second control information that is the same for the new frame transmission and the repeat frame transmission; a control unit for acquiring information indicating whether or not the receiver has correctly received the control information consisting of the first and second control information and data and, when the control information is not transmitted during the repeat frame transmission; and a transmission unit for transmitting a frame in which the data and the control information consisting of the first and second control information are multiplexed and for transmitting a frame in which the data the first control information are multiplexed. ### Claim 8 (depends on 7) The transmitter according to claim 7, comprising an identification information generation unit for generating identification information for identifying whether or not the second control information is contained, wherein the transmission unit transmits the identification information with said frame. ### Claim 9 (depends on 7) The transmitter according to claim 7, comprising an insertion unit for inserting a pilot, or the first control information, or the data into an empty space that appears because the second control information is not transmitted. ### Claim 10 (depends on 8) The transmitter according to claim 8, wherein the transmission unit transmits (1) the data, (2) the first control information or the control information consisting of the first and second control information and (3) pilot by time-division multiplexing, or frequency multiplexing, or code multiplexing. ### Claim 11 A wireless communication system, which comprises a transmitter and a receiver, and in which a frame comprising data and control information necessary for reception processing of the data is transmitted from the transmitter to the receiver and, when a reception failure is notified by the receiver, the transmitter retransmits the frame that failed to be received, wherein the transmitter comprises: a control information generation unit for generating first control information that can be different for a new frame transmission and a repeat frame transmission and second control information that is the same for the frame transmission and the repeat frame transmission; a control unit for acquiring information indicating whether or not the receiver has correctly received the control information consisting of the first and second control information and data and, when the control information has been correctly received, executing control so that the second control information is not transmitted during the repeat frame transmission; an identification information generation unit for generating identification information for indentifying whether or not the second control information is contained in the frame; and a transmission unit for transmitting a frame in which (1) the data, (2) the first control information or the control information consisting of the first and second control information, and (3) the identification information are multiplexed; and the receiver comprises; a receiving unit for receiving the frame; a normal reception check unit for checking whether the control information consisting of the first and second control information and data have been correctly received for each reception of the frame, and conveying the check results to the transmitter; a control information storage unit for storing the second control information contained in the frame; and a reception control unit for indentifying whether the second control information is contained in the frame based on the indentification information contained in the frame and, when the second information is contained in the frame, executing reception control of the data based on the received first and second control information, and storing the second control information, and when the second information is not contained in the frame, executing the reception control of the data based on the first control information that has been received and the second control information that has been stored. ### Claim 12 (depends on 11) The wireless communications system according to claim 11, wherein the transmission unit comprises an insertion unit for inserting a pilot, or the first control information, or the data into an empty space that appears because the second control information is not transmitted. ### Claim 13 (depends on 11) The wireless communication system according to claim 11, wherein the transmission unit transmits (1) the data, (2) the first control information or the control information consisting of the first and second control information and (3) pilot by time-division multiplexing, of frequency multiplexing, or code multiplexing.