35results about How to "Efficient retransmission" patented technology

The present invention provides a data transmitting method with hybrid automatic repeat request in multi-carrier system. In this method, the signal-to-noise ratios of respective sub-carriers are compared with a threshold, the data on the sub-carriers having the signal-to-noise ratios lower than the threshold are selectively retransmitted by mapping these data onto the sub-carriers having the good channel conditions, and then the retransmitted data are combined hybrid-automatically in the receiver of the opposite terminal. By using the method the system throughput can be enhanced effectively without impairing the bit error rate of the system.

A method for retransmitting signals in a MIMO system that uses an HARQ scheme is provided. In the method, an additional codeword-to-layer mapping scheme for retransmission in a MIMO system that uses an HARQ scheme is defined and used to efficiently retransmit signals. In addition, required information is obtained using existing control information to more efficiently retransmit signals in terms of control signal overhead.

Removing adverse effects in case error detection using error detection codes cannot be performed correctly, and improving the data transmission efficiency. The turbo decoder 6 compares data which is decoded this time with data which is decoded previous time, both of which are decoded in repetitive decoding processing, to obtain discord number information indicative of the number of discordant sign bits, and sends the information to a terminal I/F unit 7 and a packet flow retransmission controlling unit 10. Even though it is determined that error detection result from a CRC recalculating unit 9 shows that there exists no bit error, in case the number of discordant sign bits is larger than a predetermined threshold value, it is determined that there is generated error. And, a packet flow retransmission controlling unit 10 sends a signal requesting retransmission of data. Furthermore, data amount to be retransmitted is varied in accordance with the number of discordant sign bits to improve the data transmission efficiency.

The embodiment of the invention provides a data transmission method for an uplink chain in wireless communication. When MAC-es SDU needs to be cut and processed, an MAC-es SDU is cut by an MAC-es protocol entity of a terminal side; and HARQ is mixed and automatically retransmitted by the MAC-es protocol entity of the terminal side. The embodiment of the invention also provides a data transmission method for an uplink chain in wireless communication, which is as follows: receiving MAC-es PDU transmitted by the MAC-es protocol entity of a network side; detecting MAC-es SDU segment cut in MAC-es PDU by the MAC-es protocol entity of the network side; carrying out reordering, macro diversity and combination on the MAC-es PDU; carrying out segment package on the MAC-es SDU segment; and carrying out demux on the MAC-es SDU. By cutting and segment package, the invention can solve the problems that the MAC-es protocol entity of the terminal side only supports the sizes of several fixed and limited RLC PDU, and has no function of cutting the PLC PDU.

A method for retransmitting data in wireless communication system is disclosed. MS can receive a NACK (Not-Acknowledge) signal from a base station (BS) through a specific downlink subframe of a specific frame in a first superframe, and the MS can retransmits the data using a second uplink subframe in a first frame in a second superframe subsequent to a first superframe. In this case, a index of the second uplink subframe may be 1. The wireless communication system can support the Half-Frequency Division Duplex (H-FDD) scheme. A first uplink subframe in the first frame of the second superframe can be punctured.

In a message retransmission apparatus, a storage unit stores store a plurality of non-transmission messages, each being assigned a respective destination device to which delivery, over a communication network, is indicated as unsuccessful. A calculation unit sets a respective retransmission time for each of the plurality of non-transmission messages. A communication unit retransmits a given non-transmission message at a given respective retransmission time a given respective destination device, and, in response to an indication that delivery of the given non-transmission message over the communication network is successful, retransmits the other non-transmission messages to the respective destination devices without waiting for the respective retransmission times thereof. Accordingly, it is possible to set retransmission periods for the plurality of non-transmission messages and retransmit only a non-transmission message of which a retransmission time arrives to the destination one by one, thereby reducing system load and enhancing retransmission efficiency.

A method for an Automatic Repeat reQuest (ARQ) at a receiver in a Multiple Input Multiple Output (MIMO) system wherein when a received packet is erroneous and the erroneous packet is received from the weakest antenna in a Space Multiplexing (SM) mode, a first smallest number of retransmissions is computed to acquire a Signal to Noise Ratio (SNR) within or above an Adaptive Modulation and Coding (AMC) level. When the first number of the retransmissions is greater than a threshold, the sender is requested to retransmit the packets from the strongest antenna in the SM mode and when the first number of the retransmissions is smaller than the threshold, the sender is requested to retransmit the packets from the weakest antenna in the SM mode.

The invention discloses a video frame structure and D2D (Device-to-Device) communication based video multicast method. The video frame structure and D2D communication based video multicast method comprises steps that a base station announces a video multicast service, and all the interested users in a cell join in the service to form a multicast cluster; the base station carries out video stream multicast for the users in the cluster by regarding the transmission time of one basic unit GOP (Group of Pictures) in a video code as a cycle; the users check received information and report sequence numbers of frames having packet loss in the GOP to the base station after the multicast sub time slot is ended; the base station after receiving feedback information of the users establishes a sequence list based on the priorities of to-be-restored frames and establishes a CQI matrix of a D2D link between target frames ACK-devices and NACK-devices; relay selection and grouping are performed based on the CQI matrix and the time Tm required for transmission of the target frame m is calculated; and after the transmission is finished, the sequence number of the current target frame in the sequence list is deleted. The video frame structure and D2D communication based video multicast method efficiently overcomes the problem that the multicast rate in the multimedia multicast is always affected by the worst fading channel in the cluster, and greatly improves the video quality within limited spectrum resources from the perspective of the user.

A data transmitter transmitting a data packet containing identifier information including a kind of data, a sequence of data, and/or a packet generating sequence. A receiver extracting a packet number and the identifier information for an error-receipt occurring data packet based upon the identifier information recorded in a header of the packet, generating retransmission control information, such as retransmission times and priority, based on the extracted packet number and the identifier information and transmitting the retransmission control information to the transmitter of the packet. The retransmitting the error-occurring data packet according to the received retransmission control information. The number of retransmissions and the retransmission priority can be varied according to characteristics of the transmitted data, so that retransmissions is suitable for the characteristics of the data and to more stably receive the data that is more influential to the restoration of the data.

A method for efficient retransmission over a satellite network including transmitting data packets to VSATs, receiving retransmission requests for at least one of the data packets from the VSATs, generating a retransmission packet based on the retransmission requests using XOR summing, transmitting the retransmission packet to the plurality of VSATs.

A retransmission method and apparatus in a multi-hop broadband wireless communication system are provided, in which if there is a failed data block among data blocks received from a source node, a Relay Station (RS) transmits a feedback message requesting retransmission of the failed data block to the source node, transmits a successfully received data block to a destination node, receives a retransmitted data block for the failed data block from the source node, transmits the received retransmitted data block to the destination node, receives from the destination node a feedback message about data blocks transmitted to the destination node, and transmits the feedback message to the source node.

A retransmission control method is provided. In the method, all base stations perform error judgment for a signal sent from a mobile station 1. Then, first and second base stations send results of error judgment to a third base station which is a communication partner of the mobile station 1. The third base station sends NACK for requesting retransmission to the mobile station 1 only when every result of error judgment of the first and second base stations indicates that there is an error.

A data transmitter transmitting a data packet containing identifier information including a kind of data, a sequence of data, and/or a packet generating sequence. A receiver extracting a packet number and the identifier information for an error-receipt occurring data packet based upon the identifier information recorded in a header of the packet, generating retransmission control information, such as retransmission times and priority, based on the extracted packet number and the identifier information and transmitting the retransmission control information to the transmitter of the packet. The retransmitting the error-occurring data packet according to the received retransmission control information. The number of retransmissions and the retransmission priority can be varied according to characteristics of the transmitted data, so that retransmissions is suitable for the characteristics of the data and to more stably receive the data that is more influential to the restoration of the data.

The invention belongs to the technical field of multi-network convergence transmission, and discloses a multi-network convergence transmission method, a multi-network convergence transmission system and a computer readable storage medium. A sender allocates a certain number of LLC frames to each link in turn according to the bandwidth ratio of each link; a receiver redundantly sends the same LLC receiving state control frame on a plurality of links; and the sender performs duplication elimination on the LLC receiving state control frame according to the received serial number field of the LLCreceiving state control frame, and judges whether negative confirmation in the fed-back LLC receiving state control frame is valid or not. According to the multi-network fusion transmission ARQ methodprovided by the invention, the bandwidth of each network is fused, large-bandwidth transmission is realized, accurate retransmission is carried out under the condition of packet loss of individual links to reduce packet loss, and unnecessary retransmission caused by different time delays of each link is reduced.

Systems, methods and articles of manufacture for retransmission of data in streaming protocols are described herein. Embodiments enable efficient retransmission of dropped packet data in guaranteed delivery or request-response data transfer protocols such as TCP. In particular, embodiments provide efficient retransmission of dropped packet data based on the short and/or long term historical reliability of the underlying client connection. An embodiment includes maintaining, for one or more clients in a client-server architecture, data representing connection characteristics for one or more client-server connections. Based on collected short-term and long-term client connection characteristics, an efficient data packet retransmission scheme is determined to optimize use of the connection for retransmitting dropped packet data.