Abstract: A method and apparatus for joint unicast using multi-user superposition coding in a wireless relay system are provided. A BS superposition-encodes first and second data messages directed to first and second MSs, respectively, scheduled at a current scheduling instant. The first and second data messages carry first and second information bit streams for the first and second MSs, respectively. The first MS has a relatively good direct link to the BS, and the second MS has a relatively bad direct link to the BS. The superposition-coded data is transmitted to the first MS and an RS connected between the BS and the first and second MSs. The RS receives the superposition-coded data from the BS, extracts the second information bit stream by decoding the superposition-coded data, and transmits a third data message carrying the second information bit stream to the first and second MSs.

Abstract: Disclosed is a method of transmitting common control information by a base station in a communication system including a first communication system and a second communication system different from each other. In the communication system, a frame for carrying the common control information includes an uplink sub-frame and a downlink sub-frame, each of which includes a resource allocation area for the first communication system and a resource allocation area for the second communication system. The method includes: configuring the common control information to be received by a mobile station belonging to the second communication system; and transmitting the common control information through the resource allocation area for the second communication system included in one of the uplink sub-frame and the downlink sub-frame.

Abstract: A method and system for transmitting/receiving data in a heterogeneous communication system. A terminal accesses a first controller of a first communication system supporting a first communication service to make a communication path to the first communication system. After making the communication path to the terminal, the first controller determines whether it is possible to provide the first communication service to the terminal over the first communication system. If it is not possible, the first controller transmits to an interworking unit a first request indicating that the terminal requires the first communication service over the second communication system. The interworking unit transmits a second request to a second controller of the second communication system in response to the first request, the second request indicating that the second controller provides the first communication service to the terminal.

Abstract: A method and system for configuring a frame in a communication system is provided.

Abstract: A transmitter for a mobile communication system based on an OFDM scheme and a method for controlling the same. The transmitter can implement a characteristic of a multiple access scheme based on an OFDM scheme, a characteristic of a CDMA scheme, and a characteristic of a frequency hopping scheme which has very strong resistance to the frequency selective fading.

Abstract: A method to transmit a packet of a BS in a communication system using a HARQ scheme is provided. The method includes assigning resource for transmitting a packet to a mobile station, and transmitting a first packet to the mobile station using the assigned resource; transmitting timing information on which a second packet is transmitted to the mobile station when the BS does not receive information indicating that the mobile station decoded the first packet successfully or when the BS receives information indicating that the mobile station failed to decode the first packet; and transmitting the second packet to the mobile station on a timing point corresponding to the timing information.

Abstract: Disclosed is a system and method for service interworking between heterogeneous communication systems. The service interworking system includes a first system and a second system that is evolved from the first system and can decode control and broadcast signals used in the first system. The first and second systems provide services by using frequency bands that do not overlap with each other.

Abstract: Disclosed is an apparatus for performing power control on a reverse channel quality indicator channel (CQICH) received from a mobile station by a base station in a mobile communication system including the base station for transmitting a power control bit for power control on reverse channels and the mobile station for controlling transmission power of the reverse channels according to the power control bit. An erasure detector determines whether to perform an erasure process by measuring reception power of the reverse channel quality indicator channel. An erasure rate calculator accumulates the erasure-determined result for N slots and calculates an erasure rate for the N slots. A control bit generator determines a ratio control bit to be transmitted to the mobile station according to the erasure rate, to issue a command to increase or decrease a CQICH traffic-to-pilot ratio.

Abstract: Disclosed is an apparatus for encoding k consecutive inputs indicating a TFCI (Transport Format Combination Indicator) of each of successively transmitted frames into a sequence of m symbols in an NB-TDD (Narrowband-Time Division Duplex) mobile communication system. An encoder encodes the k input bits into a sequence of at least 2n symbols where 2n>m, using an extended Reed-Muller code from a Kasami sequence. A puncturer performs puncturing on the sequence of 2n symbols from the encoder so as to output a sequence of m symbols.

Abstract: An apparatus and method for maintaining backward compatibility with a narrow-band wireless communication system in a wide-band wireless communication system is provided. The base station comprises a scheduler, a control information generator, a resource mapping unit and a transmitter. The terminal comprises a resource allocation information checking unit, a receiver and a transmitter.

Abstract: A method for generating a preamble sequence in an orthogonal frequency division multiplexing (OFDM) communication system having A subcarriers in a frequency domain. The method comprises generating a length-2×M×N preamble sequence, where 2×M×N is less than A, by using a length-N Golay complementary sequence and a length-M Golay complementary sequence; and assigning elements constituting the preamble sequence to 2×M×N subcarriers among the A subcarriers on a one-to-one mapping basis, assigning null data to the remaining subcarriers excluding the 2×M×N subcarriers from the A subcarriers, and then IFFT-transforming the assigned result into time-domain data.

Abstract: An apparatus and method for transmitting/receiving a PDCCH (Packet Data Control Channel) for efficient packet data transmission in a communication system supporting packet data service. To allow both TDM-transmission and TDM/CDM-transmission of packet data, the PDCCH has a different format depending on the transmission scheme of the packet data. A receiver operates in BSD (Blind Slot Detection) to detect the transmission scheme of received packet data and the format of the PDCCH.

Abstract: An apparatus and method for Automatic Repeat reQuest (ARQ) in a Multi Input Multi Output (MIMO) system. The method includes computing weights of erroneous packets and weights of transmitting antennas by using channel information; sorting the weights of the erroneous packets in descending order; sorting the weights of the transmitting antennas in ascending order; and assigning the transmitting antennas to the erroneous packets according to sorting results.

Abstract: A base station transmission apparatus for transmitting MAC (Medium Access Control) ID (Identification) information indicating a terminal to receive transmission packet data and length information of the transmission packet data in a mobile communication system for high-speed packet transmission, having an encoder for encoding a bit stream indicating the MAC ID information and generating coded symbols; a Walsh cover section for Walsh-covering the coded symbols from the encoder with a Walsh code based on the length information; and a Walsh spreader for spreading the Walsh-covered symbols from the Walsh cover section with a predetermined Walsh code.

Abstract: A method and apparatus for efficiently transmitting and receiving information about spreading codes used for a packet data-transmitting channel in a spread spectrum communication system. A BS determines Walsh codes for spreading a PDCH and transmits on a PDCCH an index of a last determined Walsh code. Also, if the determined Walsh codes cannot be fully represented by the use of the last Walsh code index only, the BS transmits a Walsh space bitmap indicating the availability of the Walsh codes individually on another PDCCH or a WAICH.

Abstract: A apparatus and method for estimating a channel condition of a forward link by a mobile station in a mobile communication system including the mobile station and a base station for performing an operation of transmitting/receiving data using a plurality of subcarriers having mutual orthogonality. The method comprises measuring carrier-to-interference ratio (C/I) values of the subcarriers using a signal received from the base station; determining from the received signal a subcarrier for transmitting feedback information in a given coherence bandwidth; generating feedback information to be transmitted over the determined subcarrier; and transmitting the generated feedback information to the base station as information for estimating a channel condition of the forward link.

Abstract: An apparatus and method for efficiently distributing energy to a packet data channel. A turbo encoder generates a sequence of systematic symbols and a sequence of parity symbols by encoding an information bit stream. An interleaver interleaves the systematic symbol sequence and the parity symbol sequence, separately and serially concatenates the interleaved systematic symbol sequence and the interleaved parity symbol sequence. An energy distributor rearranges the concatenated symbols so that the systematic symbols are disposed in a high energy-having portion of a predetermined transmission period when transmission energy varies for the transmission period. A modulator modulates the rearranged symbols.

Abstract: A method for generating a preamble sequence in an OFDM (Orthogonal Frequency Division Multiplexing) communication system that uses A sub-carriers in a frequency domain and uses N Tx (Transmission) antennas, includes the steps of: generating N sequences, each having a length of ‘B/N’, by dividing B sub-carriers from among the A sub-carriers by the ‘N’ indicative of the number of the Tx antennas; and mapping, for each of the N sequences, individual components of the sequence to the B/N sub-carriers from among the A sub-carriers on a one by one basis in order to assign the components of the sequence to the B/N sub-carriers, and assigning null data to remaining sub-carriers other than the B/N sub-carriers from among the A-sub-carriers, such that a preamble sequence of a corresponding Tx antenna is generated.

Abstract: An encoding method in a mobile communication system, for receiving 4 input information bits, encoding the 4 input information bits with different Walsh codes of length 16, and outputting a coded symbol stream having 24 coded symbols using a coded symbol stream having 16 coded symbols obtained by XORing the encoded input information bits by an XOR operator. The encoding method comprises repeating the coded symbol stream having 16 coded symbols once, and thus outputting a coded symbol stream having 32 coded symbols; and puncturing 0th, 1st, 2nd, 3rd, 4th, 5th, 6th and 16th symbols from the 32 coded symbols, and thus outputting the coded symbol stream having 24 coded symbols.

Abstract: A method for generating a preamble sequence in an orthogonal frequency division multiplexing (OFDM) communication system having A subcarriers in a frequency domain. The method comprises generating a length -M×N preamble sequence, where M×N is less than A, by using a length-N Golay complementary sequence and a length-M Golay complementary sequence; and assigning elements constituting the preamble sequence to M×N subcarriers among the A subcarriers on a one-to-one mapping basis, assigning null data to the remaining subcarriers excluding the M×N subcarriers from the A subcarriers, and then IFFT-transforming the assigned result into time-domain data.