Abstract: Systems and methods for selecting a puncturing pattern for a low density parity check (LDPC) code are disclosed. One such method comprises: selecting a puncture pattern distribution for the LDPC code; calculating a security threshold and a reliability threshold for the LDPC, the LDPC having the selected puncture pattern distribution and also described by a degree distribution; storing the selected puncture pattern distribution responsive to a security gap for the LDPC being a lowest value encountered in any prior iterations; selecting another puncture pattern distribution for the LDPC code; and repeating the calculating, the storing, and the selecting another puncture pattern distribution steps.

Abstract: Disclosed is a decoding method and device for low density parity check codes using dynamic scheduling. The low density parity check codes are sequentially decoded, and the messages are scheduled in the descending order of the difference between values before and after updating the message transmitted from the variable node to the check node.

Abstract: Disclosed is a technology for performing a communication using an ultrasonic wave in an environment where an electromagnetic shielding is so severe that a wireless communication using an electromagnetic is difficult. In the environment where the electromagnetic shielding is severe, an ultrasonic terminal according to the present invention may transmit the ultrasonic wave using a solid structure as a medium, and an ultrasonic base station may receive the ultrasonic wave using the solid structure as the medium.

Abstract: Provided are a gravity search adaptive apparatus and method. The gravity search adaptive apparatus includes: a system configured to process and output a received signal; a system modeling unit configured to receive the same signal as a signal input to the system, to convert the signal using a system modeling parameter, and to output the converted signal; and an adaptive controller configured to use a gravity search adaptive algorithm to detect the system modeling parameter so that an error signal which is a difference between an output signal of the system and an output signal of the system modeling unit converges on a minimum value when the system modeling parameter is applied to the system modeling unit.

Abstract: When an event associated with a mobile station occurs, a relay station requests a base station to allocate a dedicated control channel required for transmitting control information on the mobile station to the base station. Next, when the control information on the mobile station is generated, the relay station transmits the control information to the base station through the dedicated control channel. Accordingly, since the base station allocates the dedicated control channel to the relay station in advance before the control information is generated in the relay station, the relay station can transmit the control information to the base station with a minimum of time delay.

Abstract: Disclosed is a binary signal modulator for minimizing deterioration of receiving performance caused by phase error. The binary signal modulator receives binary signals, and converts the binary signals into complex symbols according to a predetermined mapping relation. Here, the mapping relation is generated when a plurality of mapping symbols are arranged on a plurality of trajectories so that the distance between the mapping symbols is greater than or equal to a predetermined distance and the phase between the mapping symbols is greater than or equal to a predetermined angle from among the trajectories starting from a plurality of points on the complex plane, and a distance between the trajectories is greater than or equal to the minimum distance from among the distances between the points.

Abstract: Provided is a method for switching a piconet device to a coordinator in a piconet. The method receives the latest order of precedence as the next PNC information from the current PNC. Thereafter, the method detects a P-CTA allocated to devices of the piconet using a beacon of a superframe received from the PNC. On failing to receive a beacon from the PNC, the method detects whether “beacon non-receipt” indicating information that is transmitted between piconet devices during the detected P-CTA. If the “beacon non-receipt” indicating information is not detected, the method does not perform a PNC appropriation operation. If the “beacon non-receipt” indicating information is detected, the method determines that the PNC has left the piconet without performing a normal PNC handover procedure and thus performs a PNC appropriation operation according to the order of precedence information.

Abstract: A method for signal transmission of a relay, includes estimating a first modulation/demodulation channel between a transmitter and the relay and a second modulation/demodulation channel between the relay and a receiver, and an interference channel of the relay, receiving a radio frequency signal from a transmitter, generating a transformation vector using the channel estimate in order to reduce self-interference of the relay under a predetermined level, converting the radio frequency signal using the transformation vector, and transmitting the converted radio frequency signal to the receiver.

Abstract: Provided is a carrier frequency recovering apparatus and method based on phase shift. The carrier frequency recovering apparatus can recover carrier frequency based on phase shift caused by a frequency offset to thereby perform demodulation without deterioration, no matter how large the frequency offset is, and minimize structural complexity, although a frequency offset tolerance range is higher than a symbol rate and a method thereof. The carrier frequency recovering apparatus includes a phase shift estimation part for estimating a phase shift value caused by a frequency offset based on a received preamble signal; a compensation part for compensating a receiving signal based on the estimated phase shift value obtained in the phase shift estimation part prior to differential decoding; and a detection part for detecting the compensated signal obtained in the compensation part.

Abstract: A retransmission method maps at least some bits of codeword to symbols according to a first modulation method at the time of first transmission. The retransmission method maps at least some bits of the codeword to symbols according to a second modulation method that is different from the first modulation method at the time of second transmission after the first transmission. In this case, the second modulation method may have a lower modulation order than that of the first modulation method, or a sum of average reliability per bit of symbol according to the second modulation may be larger than a sum of average reliability per bit of symbol according to the first modulation method.

Abstract: In a symbol mapping apparatus, a channel coder outputs a codeword including a plurality of information bits and a plurality of redundancy bits by encoding transmission data. A symbol mapper maps the codeword to the symbol while changing a mapping scheme in the unit of the codeword.

Abstract: An apparatus and method for measuring radio relay channel are provided capable of easily measuring a radio relay channel on each radio link among a base station (BS), a relay station (RS) and a mobile station (MS) and providing a reliable result of measuring the characteristics of radio relay channel by controlling transmission/reception timing based on variation in operation time among the BS, the RS and the MS.

Abstract: In a symbol mapping method, transmission data is encoded to output information bits and redundancy bits. The information bits and the redundancy bits are mapped to a symbol according to a first mapping scheme at a first transmission, and the information bits and the redundancy bits are mapped to a symbol according to a second mapping scheme at a second transmission.

Abstract: A RF relay of a full-duplex generates a conversion matrix to belong to a null space of a channel matrix of an interference channel, generates a transmitting signal by converting a received signal using the conversion matrix, and then outputs the transmitting signal to a transmitting antenna. Therefore, an interference signal of an electromagnetic wave level (EM level) that can be generated while the transmitting signal passes through the interference channel can be canceled.

Abstract: Disclosed a transmission apparatus in a CDMA mobile communication system. Transmission frames each have a plurality of time slots, and each of the time slots includes two data parts having the same length, a midamble intervening between the data parts, and a guard period for dividing the consecutive time slots. The transmission apparatus modulates the frames into a radio signal with a modulation signal and transmits the modulated radio signal using a plurality of antennas. A power amplifier amplifies the radio signal. A controller generates a switching control signal in a guard period of time slots of a frame associated with the radio signal amplified by the power amplifier. A switch switches the amplified radio signal from the power amplifier between a first and a second antenna in response to the switching control signal.

Abstract: An access point allocates a resource for ranging to an access terminal included therein, and receives a ranging channel that includes an identifier of the access terminal and a plurality of pilots. The AP checks the access terminal by using the received identifier, and measures a round trip delay of the access terminal based on the received pilots.

Abstract: The present invention relates to an apparatus and a method for selection of a precoding matrix. In the present invention, a precoding matrix to enable an effective signal-to-noise ratio (ESNR) to have a maximum value with respect to a signal vector that requires retransmission is selected in a codebook and fed back to a transmitter. Accordingly, since the effective signal-to-noise ratio has the maximum value after the signal vector is retransmitted, it is possible to minimize a reception error probability of retransmission.

Abstract: In a symbol mapping method, transmission data is encoded to generate information bits and redundancy bits. An average LLR value of bits on which the information bits are mapped is different from an average LLR value of bits on which the redundancy bits are mapped.

Abstract: Disclosed is a transmitting/receiving method in a multi-user multiple-input multiple-output (MU-MIMO) channel. The transmitting method includes: performing QR decomposition on a Hermitian transpose matrix of a channel matrix to obtain a first matrix and a second matrix as a triangular matrix; obtaining a preprocessing matrix by using the first matrix; and forming an effective channel based on the preprocessing matrix by a block triangulation technique.

Abstract: Provided is that a base station that receives an index and a path attenuation difference of a monitoring sector from a mobile station and receives an amount of interference of the monitoring sector from a base station that corresponds to the monitoring sector. In addition, the base station measures an interference state of the monitoring sector by using the amount of interference and the path attenuation difference and calculates a control value of uplink power based on the interference state of the monitoring sector. Further, the base station transmits the control value of the uplink power to the mobile station.