Abstract: A first device may encode a first bit sequence of length K including a first information block, a second information block, a first cyclic redundancy check (CRC) for the first information block, and a second CRC for the second information block, based on a polar code of size; transmit a first signal based on the encoded first bit sequence; receive first hybrid automatic repeat request acknowledgement/negative-acknowledgement (HARQ ACK/NACK) information for the first bit sequence; divide the second information block into a first sub information block and a second sub information block and generate a third CRC for the first sub information block based on the first HARQ ACK/NACK information including information indicating failure of the transmission of the second information block; encode a second bit sequence including the third CRC based on the polar code; and transmit a second signal based on the encoded second bit sequence.

Abstract: A method for transmitting signals using polar coding to a second device by means of a first device according to the present disclosure may include: a step for encoding a first bit sequence of length K which includes a first information block, a second information block, a first cyclic redundancy check (CRC) for the first information block, and a second CRC for the second information block, on the basis of a polar code of size N; a step for transmitting a first signal on the basis of the encoded first bit sequence; a step for receiving first hybrid automatic repeat request acknowledgement/negative-acknowledgement (HARQ ACK/NACK) information for the first bit sequence; a step for dividing the second information block into a first sub information block and a second sub information block and generating a third CRC for the first sub information block, on the basis of the first HARQ ACK/NACK information including information indicating failure of the transmission of the second information block; a step for encoding

Abstract: The present specification provides a method for performing a physical layer security-based hybrid automatic repeat request (HARQ). The method comprises the steps of: generating a first code comprising information bits for forming data to be transmitted, and non-information bits which are unrelated to the data to be transmitted; generating a second code, having a length which differs from that of the first code, by puncturing the first code; determining locations of the information bits and non-information bits within the second code such that a variance of mutual information for each of the information bits and the non-information bits is maximized; and performing the HARQ by using the second code in which the locations of the information bits and the non-information bits are determined.

Abstract: Provided are a method and an apparatus for performing a HARQ based on a polar code in a wireless communication system. The apparatus transmits multiple first output bits, which are generated from multiple first input bits, to a receiver. Upon receiving a retransmission request, the apparatus generates multiple second output bits from multiple second input bits. The apparatus selects multiple third output bits from among the multiple second output bits, and transmits the selected multiple third output bits to the receiver. Bits, which are encoded differently from the multiple first output bits among the multiple second output bits, are preferentially selected as the multiple third output bits.

Abstract: Disclosed herein is method and device for performing a Hybrid Automatic Repeat request (HARQ) based on polar codes in a wireless communication system. A transmitter transmits a first packet to a receiver. The transmitter receives a re-transmission request for the first packet from the receiver. The transmitter transmits a second packet to the receiver. Herein, each of the first packet and the second packet includes at least one information bit and at least one frozen bit. An information bit having a smallest mutual information corresponding to a bit channel within the first packet is re-transmitted through a first bit channel capable of transmitting at least one information bit included in the second packet. Alternatively, a new information bit is transmitted through a second bit channel capable of transmitting at least one information bit included in the second packet.

Abstract: Provided are a method and an apparatus for performing a HARQ based on a polar code in a wireless communication system. The apparatus transmits multiple first output bits, which are generated from multiple first input bits, to a receiver. Upon receiving a retransmission request, the apparatus generates multiple second output bits from multiple second input bits. The apparatus selects multiple third output bits from among the multiple second output bits, and transmits the selected multiple third output bits to the receiver. Bits, which are encoded differently from the multiple first output bits among the multiple second output bits, are preferentially selected as the multiple third output bits.

Abstract: The present specification provides a method for performing a physical layer security-based hybrid automatic repeat request (HARQ). The method comprises the steps of: generating a first code comprising information bits for forming data to be transmitted, and non-information bits which are unrelated to the data to be transmitted; generating a second code, having a length which differs from that of the first code, by puncturing the first code; determining locations of the information bits and non-information bits within the second code such that a variance of mutual information for each of the information bits and the non-information bits is maximized; and performing the HARQ by using the second code in which the locations of the information bits and the non-information bits are determined.

Abstract: Disclosed herein is method and device for performing a Hybrid Automatic Repeat request (HARQ) based on polar codes in a wireless communication system. A transmitter transmits a first packet to a receiver. The transmitter receives a re-transmission request for the first packet from the receiver. The transmitter transmits a second packet to the receiver. Herein, each of the first packet and the second packet includes at least one information bit and at least one frozen bit. An information bit having a smallest mutual information corresponding to a bit channel within the first packet is re-transmitted through a first bit channel capable of transmitting at least one information bit included in the second packet. Alternatively, a new information bit is transmitted through a second bit channel capable of transmitting at least one information bit included in the second packet.

Abstract: There is a provided a method for deciding transmission power in order to transmit at least one of secret data and non-secret data. The method may comprise: determining whether data to be transmitted by a transmitting device is sensitive to a delay; determining whether both the secret data and the non-secret data are required to be simultaneously transmitted when the data to be transmitted is sensitive to the delay; and applying different weights to the secret data and the non-secret data and deciding transmission power to maximize a total channel capacity according to the application, when it is determined that both the secret data and the non-secret data are required to be transmitted.

Abstract: A method and apparatus for secured data transmission is provided. The base station determines a first precoding matrix based on channel information of an eavesdropper. The base station determines a second precoding matrix and a third precoding matrix. The base station generates the secure data by precoding first user data for a target user with the first precoding matrix and the second precoding matrix. The base station transmits the secure data signal to the target user. The second precoding matrix is determined based on the first precoding matrix and the first channel information. The third precoding matrix is determined based on the first channel information and the second channel information.

Abstract: A communication apparatus and method using a massive multiple input multiple output (MIMO) is disclosed, the method including measuring a transmission capacity between terminals disposed in a cell and a base station when a number of terminals disposed in the cell of the base station is greater than a number of terminals to be supported by the base station, and selecting at least one terminal for maximizing a network capacity from among terminals disposed in the cell based on the transmission capacity and the number of terminals to be supported by the base station.

Abstract: There is a provided a method for deciding transmission power in order to transmit at least one of secret data and non-secret data. The method may comprise: determining whether data to be transmitted by a transmitting device is sensitive to a delay; determining whether both the secret data and the non-secret data are required to be simultaneously transmitted when the data to be transmitted is sensitive to the delay; and applying different weights to the secret data and the non-secret data and deciding transmission power to maximize a total channel capacity according to the application, when it is determined that both the secret data and the non-secret data are required to be transmitted.

Abstract: A method and apparatus for secured data transmission is provided. The base station determines a first precoding matrix based on channel information of an eavesdropper. The base station determines a second precoding matrix and a third precoding matrix. The base station generates the secure data by precoding first user data for a target user with the first precoding matrix and the second precoding matrix. The base station transmits the secure data signal to the target user. The second precoding matrix is determined based on the first precoding matrix and the first channel information. The third precoding matrix is determined based on the first channel information and the second channel information.

Abstract: In a multi-input multi-output communication system receiving signals transmitted through a plurality of transmission antennas by using a plurality of reception antennas, a matrix determining a position of a symbol to be detected from a received signal is calculated at a first symbol detection step, and from the subsequent step, a matrix at the current step is acquired through a simple relationship from the matrix calculated at the previous step to determine a position of a symbol to be detected.

Abstract: Disclosed is a method of detecting signals at a receiver of a communication system with a multiple input multiple output antenna. With the signal detection method, a square of the distance between a received signal vector and a channel status-considered transmission symbol vector is calculated first, and the square of the distance is then classified into first and second components. The first component is minimized to calculate a plurality of first soft symbol estimates. A solution set of the first component is calculated on the basis of the plurality of first soft symbol estimates. The second component is minimized to calculate a plurality of second soft symbol estimates. A solution set of the second component is calculated on the basis of the plurality of second soft symbol estimates. A final solution set is calculated by doing the sum of the first component solution set and the second component solution.

Abstract: The present invention relates to a transmission symbol detection method in a multiple antenna system. In the present invention, when a channel matrix is estimated through channel estimation, a receiving side calculates a Q matrix and an R matrix through QR decomposition that is more simplified than a typical QR decomposition from an augmented channel matrix that includes the estimated channel matrix. In addition, the receiving side detects symbols having the minimum Euclidean metric by using the two matrixes, as transmission symbols.

Abstract: In a multi-input multi-output communication system receiving signals transmitted through a plurality of transmission antennas by using a plurality of reception antennas, a matrix determining a position of a symbol to be detected from a received signal is calculated at a first symbol detection step, and from the subsequent step, a matrix at the current step is acquired through a simple relationship from the matrix calculated at the previous step to determine a position of a symbol to be detected.

Abstract: Disclosed is a method of detecting signals at a receiver of a communication system with a multiple input multiple output antenna. With the signal detection method, a square of the distance between a received signal vector and a channel status-considered transmission symbol vector is calculated first, and the square of the distance is then classified into first and second components. The first component is minimized to calculate a plurality of first soft symbol estimates. A solution set of the first component is calculated on the basis of the plurality of first soft symbol estimates. The second component is minimized to calculate a plurality of second soft symbol estimates. A solution set of the second component is calculated on the basis of the plurality of second soft symbol estimates. A final solution set is calculated by doing the sum of the first component solution set and the second component solution.

Abstract: The present invention relates to a transmission symbol detection method in a multiple antenna system. In the present invention, when a channel matrix is estimated through channel estimation, a receiving side calculates a Q matrix and an R matrix through QR decomposition that is more simplified than a typical QR decomposition from an augmented channel matrix that includes the estimated channel matrix. In addition, the receiving side detects symbols having the minimum Euclidean metric by using the two matrixes, as transmission symbols.

Abstract: The present invention relates to a method of detecting a space-time code in a mobile communication system. When detecting a space-time code B for a plurality of transmitting antennas, an ML (maximum likelihood) metric, which is generally calculated by using a specific structure of a matrix B, is defined as a new ML metric by reducing a variable of the ML metric. Two dependent sphere decoding processes are performed and an intersection of the decoding results is calculated, and a signal is detected from the ML metric. Therefore, since detection of the space-time code B for the plurality of transmitting antennas is performed by using the newly defined ML metric, an amount of matrix calculated can be reduced, and a calculation amount can be reduced by performing the two dependent sphere decoding processes. Further, since a detection order of symbols is changed according to a channel situation, it is possible to improve the performance of the system.