Abstract: An apparatus and method for assigning sub-carriers in an orthogonal frequency division multiplex (OFDM) system are disclosed. In the apparatus and method, data is transmitted through at least one transmit antenna. At least two sub-carriers in a predetermined frequency band are assigned to a user equipment (UE), for data transmission. A Node B groups sub-carriers available to the OFDM system into sub-carrier groups, each having at least two sub-carriers, transmits data to the UE on sub-carriers in the sub-carrier groups, selects at least one sub-carrier group for the UE based on channel condition information about each of the sub-carrier groups received from the UE, and assigns the selected sub-carrier group to the UE.

Abstract: An apparatus and method for demodulating signals transmitted from one or more Node-Bs using transmit diversity methods determined on a Node-B basis in a mobile communication system based on code division multiple access (CDMA). In the apparatus, a plurality of fingers assigned on a path-by-path basis discriminates among multipath signals received from the one or more Node-Bs. A combiner selectively combines signals output from the fingers according to the use of transmit diversity. A transmit diversity signal processor demodulates the signals combined by the combiner on the basis of one transmit diversity method determined by a transmit diversity controller. The transmit diversity controller determines the transmit diversity method through transmit diversity information received from the Node-Bs, and controls the transmit diversity signal processor according to the determined transmit diversity method.

Abstract: An apparatus and method for transmitting a control signal using a symbol or bit pattern of an existing pilot channel, instead of using the time multiplexing method in the separate code channel or the existing physical channel, and reducing an error rate while a reception side detects the control signal are provided. For that purpose, a transmission side allocates transmission power corresponding to a pilot pattern determined according to the control information. A corresponding reception side detects control information based on a pilot pattern of pilot bits inserted in a dedicated physical channel (DPCH) and generates transmit power control (TPC) bits referring to a target reception power which is set based on the control information.

Abstract: An apparatus and method for Transmit Diversity mode transition in a mobile communication system for use with transmit diversity is disclosed. In a mobile communication system including a Node B comprising one or more antennas and a Mobile Station (MS) for transmitting Transmit Diversity information to the Node B to enable the plurality of antennas to implement the maximum Transmit Diversity. The apparatus and method for assigning weights to transmission data of the antennas to enable the Node B to implement the maximum Transmit Diversity when the mode transition occurs in the Transmit Diversity modes comprise determining whether the mode transition occurs using the Transmit Diversity information; and assigning a weight generated considering the relationship between a current weight and a previous weight used before the mode transition time to the data transmitted over the antennas if it is determined that the mode transition occurs.

Abstract: An apparatus and method for receiving a signal in a MIMO communication system are provided. In the signal receiving method, a first received signal received at each of the receive antennas is equalized in a predetermined first method. Each of the equalized transmit antenna signals is despread with a plurality of spreading codes used in a transmitter. The strongest transmit antenna signal is detected among the despread transmit antenna signals, and decoded in a predetermined second method, for error verification. The verified strongest transmit antenna signal is reproduced as an interference signal. A second received signal is generated by subtracting the interference signal from the first received signal and equalized in the first method. The above operation is repeated on the equalized transmit antenna signals except the strongest transmit antenna signal.

Abstract: An apparatus and method for assigning sub-carriers in an orthogonal frequency division multiplex (OFDM) system are disclosed. In the apparatus and method, data is transmitted through at least one transmit antenna. At least two sub-carriers in a predetermined frequency band are assigned to a user equipment (UE), for data transmission. A Node B groups sub-carriers available to the OFDM system into sub-carrier groups, each having at least two sub-carriers, transmits data to the UE on sub-carriers in the sub-carrier groups, selects at least one sub-carrier group for the UE based on channel condition information about each of the sub-carrier groups received from the UE, and assigns the selected sub-carrier group to the UE.

Abstract: Disclosed is an apparatus and method for receiving a channel signal using a STTD (Space Time Transmit Diversity) scheme in a CDMA communication system. In the CDMA communication system a transmitter with first and second antennas STTD (Space Time Transmit Diversity)-encodes a channel signal having PC (Power Control) information of a receiver and transmits a STTD-encoded result over first and second antennas, a first antenna signal processor receives a signal transmitted from the transmitter, and processes the received signal as a signal transmitted from the first antenna using a first pattern, a second antenna signal processor processes the received signal as a signal transmitted from the second antenna using a second pattern orthogonal to the first pattern, and an adder combines an output signal of the first and second antenna signal processor, and generates the PC information, resulting in no delay time while detecting such PC information.

Abstract: An apparatus and method for transmitting control information in a mobile communication system are disclosed. The apparatus and method include selecting a pilot signal having different predetermined pilot patterns according to whether the data are received and the data contain an error, and inserting the selected pilot signal into a pilot field of a dedicated physical channel frame as control information and transmitting the dedicated physical channel frame.

Abstract: An apparatus and method for transmitting/receiving control information using a pilot pattern inserted in a plot field of a dedicated physical channel in a mobile communication system including a transmitter for transmitting data and a receiver for receiving the data. The apparatus and method include selecting control information according to whether the data is received; and selecting a pilot pattern according to the control information, and inserting the selected pilot pattern in a pilot field of a dedicated physical channel as the control information, before transmission. The pilot pattern includes a first pilot pattern used when the control information is not transmitted, a second pilot pattern being orthogonal with the first pilot pattern, and a third pilot pattern generated by inverting a sign of the second pilot pattern.

Abstract: An apparatus and method for transmitting a control signal using a symbol or bit pattern of an existing pilot channel, instead of using the time multiplexing method in the separate code channel or the existing physical channel, and reducing an error rate while a reception side detects the control signal are provided. For that purpose, a transmission side allocates transmission power corresponding to a pilot pattern determined according to the control information. A corresponding reception side detects control information based on a pilot pattern of pilot bits inserted in a dedicated physical channel (DPCH) and generates transmit power control (TPC) bits referring to a target reception power which is set based on the control information.

Abstract: An apparatus and method are provided for determining a data rate by means of control information in a mobile communication system which includes a User Equipment (UE) and a Node B. The UE transmits data to the Node B, and the Node B transmits the control information to the UE. The data rate is determined by means of the control information and is used for transmission of the data by the UE. The apparatus and method comprise determining a preliminary data rate in consideration of a quantity of data waiting for transmission; comparing the preliminary data rate with a previous data rate used for previous data transmission; and determining the data rate according to a result of comparison so that the UE can transmit the data at the data rate.

Abstract: An apparatus and a method for transmitting control information in a mobile communication system are disclosed. In a mobile communication system including a transmitter for transmitting data and a receiver for receiving the data, when transmitting information regarding whether the data have been received, the receiver generates identifiers having different signs according to whether received data contain an error, adds the generated identifiers to a physical channel, and transmits the physical channel. The transmitter detects a sign corresponding to an existence or absence of an error from the information regarding whether or not the data have been received, detects transmission error for the data according to the detected sign, and determines whether the data are retransmitted according to a result of the detection.

Abstract: A frequency error detector and combiner for use in a mobile communication system. The frequency error detector and combiner for use in a receiver of a mobile communication system which includes different frame formats according to slot formats, the receiver having at least two fingers including a frequency error detector for detecting a frequency error using a phase reference symbol of a predetermined channel received from a transmitter and a reference frequency error generator for generating a reference frequency error at predetermined reference time intervals using the detected frequency error; a level controller for controlling the gain of a frequency error generated from the reference frequency error generator; and a frequency error combiner for combining the gain controlled frequency error generated from each finger with a predetermined value.

Abstract: An apparatus and method for Transmit Diversity mode transition in a mobile communication system for use with transmit diversity is disclosed. In a mobile communication system including a Node B comprising one or more antennas and a Mobile Station (MS) for transmitting Transmit Diversity information to the Node B to enable the plurality of antennas to implement the maximum Transmit Diversity. The apparatus and method for assigning weights to transmission data of the antennas to enable the Node B to implement the maximum Transmit Diversity when the mode transition occurs in the Transmit Diversity modes comprise determining whether the mode transition occurs using the Transmit Diversity information; and assigning a weight generated considering the relationship between a current weight and a previous weight used before the mode transition time to the data transmitted over the antennas if it is determined that the mode transition occurs.

Abstract: Disclosed are an apparatus and a method capable of preventing performance degradation during a channel decoding process. A bit interleaving is performed with respect to parity bits among coded bits output through a channel coding unit, thereby preventing a repetition period of the parity bits from matching a puncturing period for a rate matching. A bit de-interleaving is performed with respect to the parity bits during a channel decoding process, so that the parity bits have a repetition period identical to initial parity bits. Thus, the repetition period of the parity bits is not matched with the puncturing period for the rate matching, thereby preventing performance degradation during the channel decoding process.

Abstract: Disclosed is a reception apparatus employing a post-descrambling scheme in a mobile communication system for code division multiple access and provides methods which are used for channel-compensating received multi-path signals, sorting the channel-compensation signals according to positions in time in consideration of multi-path latency, combining the sorted signals, and descrambling each of the combined signals by means of one of preset scrambling codes in a reception apparatus of Code Division Multiple Access (CDMA) mobile communication system.

Abstract: An apparatus and method for demodulating signals transmitted from one or more Node-Bs using transmit diversity methods determined on a Node-B basis in a mobile communication system based on code division multiple access (CDMA). In the apparatus, a plurality of fingers assigned on a path-by-path basis discriminates among multipath signals received from the one or more Node-Bs. A combiner selectively combines signals output from the fingers according to the use of transmit diversity. A transmit diversity signal processor demodulates the signals combined by the combiner on the basis of one transmit diversity method determined by a transmit diversity controller. The transmit diversity controller determines the transmit diversity method through transmit diversity information received from the Node-Bs, and controls the transmit diversity signal processor according to the determined transmit diversity method.

Abstract: Disclosed is an apparatus and method for receiving a channel signal using a STTD (Space Time Transmit Diversity) scheme in a CDMA communication system. In the CDMA communication system a transmitter with first and second antennas STTD (Space Time Transmit Diversity)-encodes a channel signal having PC (Power Control) information of a receiver and transmits a STTD-encoded result over first and second antennas, a first antenna signal processor receives a signal transmitted from the transmitter, and processes the received signal as a signal transmitted from the first antenna using a first pattern, a second antenna signal processor processes the received signal as a signal transmitted from the second antenna using a second pattern orthogonal to the first pattern, and an adder combines an output signal of the first and second antenna signal processor, and generates the PC information, resulting in no delay time while detecting such PC information.