Abstract: Disclosed is a channel spreading device for a base station device in a CMDA communication system for spreading input symbols using a first quasi-orthogonal code having a first length or channel spreading the input symbols using a second quasi-orthogonal code having a second length which is a multiple of the first length. The device comprises a spreading code generator for generating the second quasi-orthogonal code; a channel spreader for providing a plurality of durations by dividing a duration of the second quasi-orthogonal code by said multiple of the length of the first quasi-orthogonal code, and spreading channel coded symbols with the quasi-orthogonal codes divided to have a length corresponding to the divided durations so as to spread the symbols identical in number to said multiple of the first quasi-orthogonal code duration at the duration of the second quasi-orthogonal; and a PN spreader for spreading the channel spread signal with a PN code.

Abstract: Method and apparatus for providing a packet data service between a terminal and a base station in a mobile communication system includes packet data being transmitted from the terminal (base station) on a reverse (forward) packet traffic channel to the base station (terminal) during a data transmission period; the occupation of the reverse (forward) packet traffic channel is released during a data transmission suspension period; and the base station controls the reverse (forward) packet traffic channel over a packet control channel.

Abstract: A code division multiple access (CDMA) mobile communication system for controlling power for a traffic signal of one frame includes: a signal generator for simultaneously generating a pilot signal and the traffic signal on a frame basis; a power compensator for compensating the power of the traffic signal according to a punctured length of a punctured frame among the frames; and a signal combiner for combining the power-compensated traffic signal and the pilot signal generated from the signal generator.

Abstract: A spreading code generating device for a Code Division Multiple Access (CDMA) communication system. The device comprises a PN (Pseudorandom Noise) code sequence generator for generating PNi and PNq sequences; an orthogonal code generator for generating first and second orthogonal codes which perform Differential Phase Shift Keying (DPSK) state transitions at intervals of at least two chips; and a spreading code generator for generating spreading codes Ci and Cq by mixing the PNi and PNq code sequences with the first and second orthogonal codes such that a present phase of the spreading codes Ci and Cq alternately makes Quadrature Phase Shift Keying (QPSK) and DPSK state transitions with respect to a previous phase of the spreading codes Ci and Cq.

Abstract: A base station and a mobile station for a CDMA communication system intermittently exchange data on a power control group unit or time slot unit in a control hold state to minimize interference. To this end, during channel transmission, the system intermittently transmits a reverse pilot channel signal in the control hold state; upon activation of a reverse dedicated control channel, transmits a normal pilot channel signal which is first generated after activation of the reverse dedicated control channel; and then transmits the reverse dedicated control channel.

Abstract: A device for time alignment on a reverse link in a CDMA mobile communication system. A base station stores a reference sync channel RTD (Round Trip Delay), calculates the difference between the reference sync channel RTD and a measured sync channel RTD, and outputs a time alignment control signal on a forward control channel when the calculated RTD error exceeds a predetermined value, during a data communication. A terminal receives the time alignment control signal on the forward control channel and time aligns a reverse traffic channel based on the received time alignment control signal.

Abstract: A device and method for cancelling code interference in a receiver of a CDMA (Code Division Multiple Access) communication system simultaneously using orthogonal codes and quasi-orthogonal codes are provided. In a receiver according to an embodiment of the present invention, a channel estimator produces a channel estimation value of a pilot channel signal spread by an orthogonal code through despeading. A quasi-orthogonal channel receiver receives a channel signal spread by a quasi-orthogonal code, despreads the channel signal, demodulates the despread channel signal by use of the channel estimation value, and provides an output. An interference estimator estimates an interference value of the pilot channel signal with the channel signal spread by the quasi-orthogonal code by obtaining a correlation value between the orthogonal code corresponding to a pilot channel and the quasi-orthogonal code corresponding to a quasi-orthogonal channel.

Abstract: A short PN code generating device in a mobile communication network having a N× CDMA communication system performing spreading at an N× chip rate using a short PN code of chip length N×2k and a 1× CDMA communication system performing spreading at a 1× chip rate using a short PN code of chip length 2k. The device generates a short PN code such that the N× CDMA communication system can distinguish at least the same number of base stations as the 1× CDMA communication system can distinguish. The device includes a sequence generator for generating an m-sequence having a chip length longer than the chip length N×2k to output an I-component short PN code; and a short PN code generator for switching the generated m-sequence at predetermined chip periods to alternately output the m-sequence as an I-component short PN code and a Q-component short PN code.

Abstract: Packet data communicating device and method in a CDMA communication system. According to a first embodiment, a transmitting device for a base station includes a data generator for generating frame data to be transmitted, a first mask generator for generating a long code mask for a forward common channel, a second mask generator for generating a long code mask for a forward common channel to be designated as dedicated to a specific mobile station, a selector for selecting one of the long code masks generated in the first and second mask generators, a long code generator for generating a long code with the selected long code mask, a scrambler for mixing the frame data received from the data generator and the long code received from the long code generator, and a transmitter for spreading the scrambled frame data, for transmission.

Abstract: A CDMA communication system provides a dedicated control channel capable of efficiently communicating control messages between a base station and a mobile station. In a dedicated control channel transmission device, a controller determines a frame length of a message to be transmitted and outputs a frame select signal corresponding to the determined frame length. A message generator generates frame data of the message to be transmitted according to the frame select signal. A transmitter spreads the frame data and transmitting the spread frame data through a dedicated control channel. In a dedicated control channel reception device, a despreader despreads a received signal. A first message receiver deinterleaves and decodes the despread signal in a first frame length to output a first message, and detects a first CRC corresponding to the decoded signal.

Abstract: There are provided spread spectrum signal generating devices and methods in a transmitter of a mobile communications system using a plurality of logical channels. In the spread spectrum signal generating devices, a multiplexer time multiplexes a pilot channel signal and a control channel signal which are output at substantially constant power levels. A first orthogonal encoder orthogonally spreads the output of the multiplexer with an orthogonal code. A second orthogonal encoder orthogonally spreads voice channel data of a variable bit rate with an orthogonal code. A third orthogonal encoder orthogonally spreads packet channel data of a variable bit rate with an orthogonal code. An IQ signal mapper adds the outputs of the first and third orthogonal encoders, outputs the added signal as a first channel signal, and outputs the output of the second orthogonal encoder as a second channel signal.

Abstract: Disclosed is a power control method for a mobile station which has at least one compressed mode frame. A compressed mode frame includes a data transmission duration where data is transmitted at a first frequency, and a data transmission-off duration where a second frequency is searched to perform an inter-frequency handoff to the second frequency. The transmission power during the data transmission duration is increased to compensate for the loss of transmission power during the data transmission-off duration. In the method, a base station sets a power control threshold depending on the length of the data transmission-off duration. The base station receives transmission power-increased data and compares the received power of the data signal with the power control threshold. The base station generates a power-up command when the power control threshold is higher than the receiving power, and generates a power-down command when the power control threshold is lower than the receiving power.

Abstract: A device and method for generating a pseudo-orthogonal code for use in orthogonally spreading channel data in a CDMA mobile communications system. M orthogonal codes are selected from N orthogonal codes, for forming a pseudo-orthogonal codes, and the elements of the selected M orthogonal codes are sequentially interlaced to generate the pseudo-orthogonal code as a sequence of M×N elements.

Abstract: A device for generating quasi-orthogonal codes which allow the minimum interference with orthogonal codes in a mobile communication system using the orthogonal codes. The device includes a first spreader for spreading at least one input signal with quasi-orthogonal codes, a second spreader for spreading another input signal with Walsh codes, and a PN (Pseudo-Noise) spreader for complex-spreading output signals of the first and second spreaders with PN sequences. The quasi-orthogonal codes are characterized in that a partial correlation value with the Walsh codes does not exceed a lowest partial correlation limit value.

Abstract: A code set generating method in a mobile communications system having Nf frequency channels and Np phase channels. In the method, a code length Nc is obtained by Nf×Np, a minimum distance Nd between codewords in a code set and frequency diversity Nfd are determined, code sets are detected according to Nc, Nd, and Nfd, a code set is selected, which shows such a Hamming distance distribution among code words that minimizes demodulation errors from the detected code sets, and the code set is stored in a mapping table of a demodulator.

Abstract: A data service providing method for use a communications system which has a forward traffic channel including a fundamental channel and a supplemental channel. The total transmission power of a base station is detected, and when it is complemental a reference transmission power data is transmitted on a forward link via a predetermined complemental channel. The complemental data is received from the forward link, and processed in a terminal.

Abstract: A dial pulse detector in a paging system for rendering a paging service for a subscriber who uses a mechanical telephone includes a delay correlativity calculator for receiving dial pulses generated by predetermined pre-test dialing digits dialed by the subscriber, calculating the correlativity between the delayed dial pulse and undelayed dial pulse to sample a reference signal of the dial pulse. An energy correlativity calculator calculates the energy correlativity between the sampled reference signal and the successively received dial pulse to examine the validity of the reference signal. A dial pulse verifier operates according to recognition of the validity of the reference signal by the energy correlativity calculator and checks input number of times and input time of the dial pulse so as to verify whether the dial pulse corresponds to the pre-test dialing digits.

Abstract: A multiple path delay time searcher at a signal demodulation mode of a reverse link communication channel of a mobile communication system employing a code division multiple access method. The multiple path delay time searcher includes a sample buffer for storing a signal received from an antenna of a base station as a sample; a delay time searcher for obtaining a correlation value between a signal at a specific search location designated by the sample buffer and a reference signal corresponding to a specific symbol; a signal processor for deciding whether there is a signal component in the specific search location using an accumulative average of the correlation values received from the delay time searcher; and a multiple path combiner for deciding the symbol designated in the delay time searcher.