Abstract: Disclosed is an apparatus and method for supporting automatic repeat request (ARQ) in a high-speed wireless packet data communication system. A mobile station receives control information including a subpacket identifier (SP_ID) representing the sequence of a subpacket, the size of an encoder packet (EP_SIZE), and a sequence identifier (AI_SN) that is toggled each time a new encoder packet is transmitted, while receiving one of a plurality of subpackets generated by segmenting a bit stream acquired by encoding a transmission encoder packet. The mobile station determines whether it will perform a decoding process caused by initial transmission or a decoding process caused by retransmission on the received subpacket, based on the control information.

Abstract: An apparatus and method for transmitting packet data in a high-speed packet transmitting mobile communication system. In the packet data transmitting apparatus, a packet data channel generator processes packet data to be transmitted on a packet data channel, a preamble signal generator transmits a preamble signal according to a gain of the packet data channel, a select signal generator generates a select signal to transmit the preamble signal a predetermined time before transmitting the packet data, and a multiplexer outputs the preamble signal upon receipt of the select signal and the packet data in time division when the select signal is not received.

Abstract: An apparatus and method for receiving control information transmitted from a transmitter using one of a plurality of slot lengths in a high-speed packet transmission mobile communication system is provided. The apparatus and method includes a decoder adapted to receive symbols by the slot, and generate at least one bit stream by decoding as many symbols of at least one possible slot length among a plurality of slot lengths according to a previous decoding result. An error checker adapted to perform error checking on the bit stream from the decoder. A controller is adapted to provide symbols of one more consecutive slot to the decoder, if the error checking failed, and acquire control information from the error checking-passed bit stream, if the error check passed. The decoder is further adapted to output at least one frame quality metric for the bit stream along with the bit stream.

Abstract: An apparatus for detecting a frame transmission period in a CDMA mobile communication system supporting a discontinuous transmission mode. A first frame detector performs primary frame detection by calculating a signal-to-interference ratio (SIR) using traffic symbol energy, pilot symbol energy and noise energy measured for a predetermined time period, and comparing the SIR with a predetermined frame detection threshold value. A decoder calculates a symbol error rate (SER) by decoding symbols received for the predetermined time period. A second frame detector selects an SER threshold value according to frame detection information from the first frame detector, and compares the selected SER threshold value with the SER to determine whether a frame has been transmitted.

Abstract: Disclosed is an apparatus and method for transmitting and receiving control information for a packet data channel in a mobile communication system supporting a high-speed packet data service and a circuit voice service. A base station generates control information indicating an encoder packet size, a code rate and the number of Walsh codes used for transmission of packet data to a mobile station, and transmits the generated control information over a packet data control channel. The mobile station receives the control information over the packet data control channel while receiving the packet data over the packet data channel, and decodes the received packet data according to a modulation order determined based on the received control information.

Abstract: An apparatus and method for measuring an SIR in a CDMA mobile communication system. The SIRs and power of PICHs and the power of PDCHs are measured sequentially for a plurality of active set base stations. An active set base station having the highest signal strength is selected according to the measurements. Thus a data rate is determined adaptively to the SIR for efficient high rate packet data transmission.

Abstract: There is provided an apparatus and method for using QOF (Quasi-Orthogonal Function) Walsh codes when enough orthogonal Walsh codes are not available for a packet data service in a mobile communication system supporting concurrent provision of a high rate packet data service and a circuit call service. A data rate (DR1) in the case of using available orthogonal Walsh codes is first obtained. Then, a data rate (DR2) in the case of using QOF Walsh codes is obtained considering a power reduction factor due to the increase of interference involved with the use of the QOF Walsh codes. Packet data is transmitted at a higher data rate of DR1 and DR2. At the same time, information about the selected data rate and information about whether the QOF Walsh codes are used or not are transmitted.

Abstract: A device for controlling transmission power of a mobile station in a multi-carrier CDMA mobile communication system, which includes a digital mixer that receives and divides a wide band multi-carrier signals according to carriers and also filters the divided carrier signals. A searcher receives and separates the divided carrier signals according to carrier signals which have the same path delay. A plurality of fingers separately (and in parallel) despread and demodulate carrier signals which have the same path delay, and synchronize the demodulated signals. Parallel/serial (P/S) converters convert the demodulated signals provided in parallel from the fingers to serial signals. De-randomizers de-randomize the converted demodulated serial signals using a subscriber identification code.

Abstract: Disclosed is a mobile station for determining a data rate for a packet data service in a mobile communication system including a base station, and the mobile station being provided with a voice service and a packet data service from the base station. In the mobile station, a receiver receives orthogonal code allocation information indicating the number of orthogonal codes allocated for the packet data service, a measurer measures a CIR using a received pilot channel, and a controller determines a data rate corresponding to the measured CIR, controls the determined data rate based on the number of the allocated orthogonal codes, and determines a controlled data rate.

Abstract: Disclosed is a packet data transmission method of a base station in a state where there is no data communication between the base station and a mobile station after transmission of packet data from the base station to the mobile station. The method comprises transmitting a DRQ (Data Rate Request) message to the mobile station after transmission of the packet data, to receive the transmitted packet data; transmitting to the mobile station an ACK message for a prescribed time period in response to a detection ACK signal of the DRQ message from the mobile station; and transmitting the packet data along with a power control signal at a data rate based on a data rate message received from the mobile station, after transmitting the ACK message.

Abstract: Disclosed are a method and apparatus for transmitting a time-discontinuous burst pilot channel being dependent on transmission data in a mobile communication system. In the apparatus, a modulator generates a modulated pilot symbol by outputting an input pilot symbol at a designated at least one of phase and on a designated complex channel according to an information bit for determining at least one of the phase and/or the complex channel, and a spreader spreads the modulated pilot symbol from the modulator with an orthogonal code selected among a plurality of orthogonal codes. The burst pilot channel transmits side information being dependent on the transmission data according to the phase, and/or the complex channel and the orthogonal code.

Abstract: The optimum electrolyte level sensing method and the automatic topping up apparatus for storage wet cell are disclosed. The difference in the conductivities between the distilled water and the electrolyte is utilized. An injection outlet portion (15), an adjust ring (14), and two wires are used to detect the optimum electrolyte level to supply distilled water to storage cells. The feedback control to maintain the constant optimum electrolyte level of storage cells is carried out by a single microprocessor.

Abstract: The optimum electrolyte level sensing method and the automatic topping up apparatus for storage wet cell are disclosed. The difference in the conductivities between the distilled water and the electrolyte is utilized. An injection outlet portion(15), an adjust ring(14), and two wires are used to detect the optimum electrolyte level to supply distilled water to storage cells. The feedback control to maintain the constant optimum electrolyte level of storage cells is carried out by a single microprocessor.