Abstract: A common packet channel assignment method and device in a CDMA (Code Division Multiple Access) communication system is disclosed. The method comprises transmitting an access preamble signal having channel information which is used to access a base station, and then receiving an; access preamble acquisition indicator signal from the base station in response to the access preamble signal. A collision detection preamble for detecting a collision is transmitted in response to the received access preamble acquisition indicator signal. A first signal indicating acquisition of the collision detection preamble and a second signal indicating channel assignment are received, both of which the base station has transmitted in response to the collision acquisition signal. Upon receipt of the first signal, a common packet channel is assigned according to information designated by the second signal.

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: 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: There is provided a data communication apparatus and method in a multi-carrier CDMA communication system. A transmitting device determines whether a supplemental channel is transmitted. If the supplemental channel is transmitted, the transmitting device assigns the supplemental channel to each of all FAs having different carrier frequency bands and the other channels including a fundamental channel, a dedicated control channel, and a common control channel to one of the FAs. A receiving device determines whether the supplemental channel exists in input channel signals. If the supplemental channel exists, the receiving device despreads supplemental channel signals in each of the FAs, connects the despread supplemental channel signals to a supplemental channel decoder, despreads the other channels in one of the FAs, and connects the other channel signals to corresponding channel decoders.

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: 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: 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: A method for generating a preamble sequence for decreasing a peak-to-average power ratio (PAPR) through at least two antennas in an orthogonal frequency division multiplexing (OFDM) communication system. The method comprises generating a first preamble sequence in which odd data of the preamble sequence becomes null data and even data of the preamble sequence becomes data, the first preamble sequence being adapted to be transmitted via one of the two antennas; and generating a second preamble sequence in which even data of the preamble sequence becomes null data and odd data of the preamble sequence becomes data, the second preamble sequence being adapted to be transmitted via another one of the two antennas.

Abstract: Disclosed is an apparatus for generating an error detection information bit sequence for determining a length of data sequence transmitted in a communication system. The apparatus comprises a plurality of cascaded registers, the number of which is identical to the number of bits in the error detection information bit sequence, and a plurality of adders arranged on paths determined by a predetermined generator polynomial, each of the adders adding a bit sequence received through an input path to a feedback bit sequence. During reception of the control information sequence, an operator generates the feedback bit sequence by sequentially adding bits of the control information sequence to output bits of a final register and provides the generated feedback bit sequence to the adders. After completion of receiving the control information sequence, the operator sequentially adds a preset input bit to output bits of the final register and outputs the addition result as the error detection information bit sequence.

Abstract: There is provided a method of providing site selection diversity in a mobile communication system. If an active set is updated, the category of the old active set is compared with that of the updated active set. According to the comparison result, station (BS) identification (ID) codes are reassigned to base stations in the updated active base set. The reassigned BS ID codes are transmitted to the corresponding base stations and the category of the updated active set is transmitted to all the base stations of the updated active set.

Abstract: An apparatus and method for providing closed-loop transmit antenna diversity in a mobile communication system is provided. To maximize the sum of the vectors of signals received from at least two antennas at a base station, a mobile terminal calculates the vectors of the signals received from the antennas of the base station, calculates differential vectors for the input signal vectors in order to maximize the sum of the input signal vectors, and transmits information about the calculated differential vectors to the base station, which uses them to maximize the sum of the vectors of signals subsequently received by the mobile terminal.

Abstract: A method and apparatus for generating a preamble sequence in an orthogonal frequency division multiplexing (OFDM) communication system having m subcarriers in a frequency domain. The method comprises generating a preamble sequence of length n that is mapped to n subcarriers on a one-to-one basis, where n is less than m; and assigning components constituting the preamble sequence to the n subcarriers among the m subcarriers on a one-to-one mapping basis, assigning null data to the remaining subcarriers excluding the n subcarriers from the m subcarriers, and then IFFT (Inverse Fast Fourier Transform)-transforming the assigned result into time-domain data.

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.

Abstract: There is provided a transmission diversity system. In the case where an MS supporting a different antenna transmission diversity scheme enters the service area of a 4-antenna transmission diversity UTRAN, the UTRAN can transmit pilot signals and common data signals to the MS without the need of modifications to the MS. Therefore, power is distributed among antennas of the UTRAN and system capacity is increased.

Abstract: A handoff implementing device and method in a mobile communication system. The handoff implementing device including a base station transmitter and a mobile station receiver. The base station transmitter divides a given frame period into a transmission period and a non-transmission period, separates frame data in the frame period into first and second data, spreads the first and second data by different orthogonal codes, and transmits the spread signal in the transmission period. The mobile station receiver receives the first and second data spread by the different orthogonal codes in the transmission period, assembles the first and second data into the frame data, and searches for an adjacent base station to which a call is handed off in the non-transmission period.

Abstract: A mobile station supporting selective transmit diversity (STD) efficiently transmits forward channel status information to a base station in a 1×EV-DV mobile communication system. The mobile station receives signals transmitted from the base station through a plurality of transmission antennas, measures signal strengths of the received signals, compares the measured signal strengths after compensating for a transmission power difference between the transmission antennas, and selects a transmission antenna having the highest signal strength. The mobile station transmits forward channel status information indicating measured signal strength for a signal transmitted from the selected transmission antenna to the base station along with antenna selection information indicating the selected transmission antenna.

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 method and apparatus for transmitting and receiving forward channel status information in a multi-carrier mobile communication system. An MS transmits to a BS forward channel status information representing an average C/I of forward signals with respect to a plurality of carriers, the maximum of the forward signal C/Is, or each of the forward signal C/is. The forward channel status information is absolute C/I information representing a current C/I, or relative C/I information representing a difference of the current C/I from a previous C/I.

Abstract: An apparatus for encoding an information bit sequence and generating coded symbols in a communication system that transmits packet data and the information bit sequence for controlling transmission of the packet data. An encoder encodes the information bit sequence at a preset coding rate and outputs coded symbols. A controller controls the encoder so that the encoder outputs the coded symbols when a frame length of the information bit sequence is a first length, and the encoder outputs partial symbols among the coded symbols when the frame length of the information bit sequence is a second length, the second length being shorter than the first length.

Abstract: A method is disclosed for determining by a UTRAN a persistence value having a value between 0 and 1 for adjusting a number of access preambles from a plurality of UEs requiring assignment of a common packet channel (CPCH). The method includes the steps of counting a number of the access preambles detected in an access preamble period having a predetermined period; and determining the persistence value based on the number of counted access preambles. The persistence value is determined in a unit of transport format (TF), physical common packet channel (PCPCH), or CPCH set.