Abstract: A method for initializing a protection device PD comprising steps of: receiving by a beacon receiver beacon information from other protection devices around the PD; sending by the beacon receiver the received beacon information to a channel monitoring decision maker within a time period set in a channel monitoring timer; determining by the channel monitoring decision maker whether there exists any primary beacon transmission device PPD; if yes, deciding the PD as a secondary beacon transmission device SPD; if no, deciding the PD as a PPD; receiving by an initialization process decision maker a determination result from the channel monitoring decision maker and determining an operation status of the PD within a time period set in the initialization process timer; outputting by the initialization process decision maker the determination result to a transmitter of the PD to decide whether the transmitter has transmitted any data or request information.

Abstract: The present invention provides a method for transmitting and receiving data in a single carrier frequency division multiple access system to which a precoding matrix is applied, and to a transmitting/receiving apparatus for same. The method for transmitting data comprises the steps of: applying selected mapping algorithm (SLM) sequences of an SLM sequence subset corresponding to a precoding matrix, to respective data; selecting the SLM sequence in which each of the applied data has the smallest peak to average power ratio (PAPR) value; and transmitting the index of the selected SLM sequence and data to which the selected SLM sequence is applied.

Abstract: The present invention relates to a method and a system for transmitting and receiving control information of an Multi-Input Multi-Output (MIMO) system, wherein the control information consists of information bits and parity bits. A base station transmits the control information including the location information for where the control information of the other terminal is transmitted. A terminal receives the control information of the other terminal based on the location information for where the control information of the other terminal is received. Therefore, the precoding matrix of the other terminal can be obtained from the received control information. The invention enables the removal of interference through the obtained precoding matrix when receiving a data symbol in an environment where a channel is not in a good state.

Abstract: A signal processing method in an MIMO multi-carrier system is disclosed comprising: receiving by a receiver signals of a plurality of sub-carriers transmitted from a transmitter; dividing the sub-carriers into a plurality of sub-carrier blocks according to the correlation between adjacent sub-carriers, each sub-carrier block containing K sub-carriers; selecting a feedback sub-carrier pre-coding matrix ( ) and a rotation matrix ( ) for each sub-carrier block, and then sending the information on the pre-coding matrix and the rotation matrix back to the transmitting end. The present invention provides the method and device for effectively settling the feedback problem in an MIMO/OFDMA system, thereby greatly reducing the number of pre-coding weight matrices needed to feed back to the transmitting device.

Abstract: Methods for maintaining continuing existence of a next-in-line protecting device in a beacon network including a primary protecting device (PPD), the next-in-line protecting device (NPD) and a plurality of secondary protecting devices (SPDs). In one method, a subset of the plurality of secondary protecting devices periodically transmit beacon messages to the primary protecting device. When the next-in-line protecting device disappears, the primary protecting device selects a secondary protecting device from among the secondary protecting devices that have transmitted the beacon messages within a certain period to be a new next-in-line protecting device. In another method, the plurality of secondary protecting devices continuously monitor an existence of the next-in-line protecting device. When the next-in-line protecting device disappears for a certain period of time, a subset of the plurality of secondary protecting devices may contend to be a new next-in-line protecting device.

Abstract: The present invention relates to a method and a system for transmitting and receiving control information of an Multi-Input Multi-Output (MIMO) system, wherein the control information consists of information bits and parity bits. A base station transmits the control information including the location information for where the control information of the other terminal is transmitted. A terminal receives the control information of the other terminal based on the location information for where the control information of the other terminal is received. Therefore, the precoding matrix of the other terminal can be obtained from the received control information. The invention enables the removal of interference through the obtained precoding matrix when receiving a data symbol in an environment where a channel is not in a good state.

Abstract: A signal processing method in an MIMO multi-carrier system is disclosed comprising: receiving by a receiver signals of a plurality of sub-carriers transmitted from a transmitter; dividing the sub-carriers into a plurality of sub-carrier blocks according to the correlation between adjacent sub-carriers, each sub-carrier block containing K sub-carriers; selecting a feedback sub-carrier pre-coding matrix ( ) and a rotation matrix ( ) for each sub-carrier block, and then sending the information on the pre-coding matrix and the rotation matrix back to the transmitting end. The present invention provides the method and device for effectively settling the feedback problem in an MIMO/OFDMA system, thereby greatly reducing the number of pre-coding weight matrices needed to feed back to the transmitting device.

Abstract: A method for initializing a protection device PD comprising steps of: receiving by a beacon receiver beacon information from other protection devices around the PD; sending by the beacon receiver the received beacon information to a channel monitoring decision maker within a time period set in a channel monitoring timer; determining by the channel monitoring decision maker whether there exists any primary beacon transmission device PPD; if yes, deciding the PD as a secondary beacon transmission device SPD; if no, deciding the PD as a PPD; receiving by an initialization process decision maker a determination result from the channel monitoring decision maker and determining an operation status of the PD within a time period set in the initialization process timer; outputting by the initialization process decision maker the determination result to a transmitter of the PD to decide whether the transmitter has transmitted any data or request information.

Abstract: Methods for maintaining continuing existence of a next-in-line protecting device in a beacon network including a primary protecting device (PPD), the next-in-line protecting device (NPD) and a plurality of secondary protecting devices (SPDs). In one method, a subset of the plurality of secondary protecting devices periodically transmit beacon messages to the primary protecting device. When the next-in-line protecting device disappears, the primary protecting device selects a secondary protecting device from among the secondary protecting devices that have transmitted the beacon messages within a certain period to be a new next-in-line protecting device. In another method, the plurality of secondary protecting devices continuously monitor an existence of the next-in-line protecting device. When the next-in-line protecting device disappears for a certain period of time, a subset of the plurality of secondary protecting devices may contend to be a new next-in-line protecting device.

Abstract: An apparatus and method for providing a relay service in an OFDM mobile communication system are provided, in which symbol synchronization is acquired from a received OFDM signal, an OFDM signal is acquired using the symbol synchronization, and a relay signal is reconfigured by removing a cyclic prefix from the acquired OFDM signal, amplifying the relay signal, and transmitting the relay signal.