Abstract: A mobile communication system is disclosed that supports soft handoff between switching stations and increase service quality. The mobile communication system can include at least one mobile switching stations having a first inter network that controls a plurality of base station controllers and at least one local switching stations coupled to the mobile switching stations. Each of the local switching stations can include a second inter network that provides a communication path between the mobile switching stations.

Abstract: Fuzzy rule-based control is applied to video rate control in the present invention. A basic fuzzy logic controlling apparatus using the occupancy as a fuzzy control variable is provided. Other fuzzy logic controlling apparatus is also provided: the video quality-controlled, the scene change based and the quality-monitored. The occupancy-based controlling apparatus is adopted to form a backbone scheme. The accumulative quality measure and the scene change features are then introduced to improve the video quality. The quality-monitored FRC(FRC-QM), which is controlled by both the quality factor and the scene change-based factor, is superior to the other schemes in respect of both the occupancy and the quality.

Abstract: A call control method in a CDMA mobile radio communication system which can maintain the forward load in a sector below a predetermined level even when a forward sector capacity is overloaded by estimating the sector forward power using powers of activated traffic channels allocated to the sector when originating and terminating calls are controlled in the mobile radio communication system. According to the call control method, a forward sector excess capacity is calculated from the sector forward power for a predetermined period, a call and/or handoff call attempt block threshold value is determined using the calculated forward sector excess capacity, and then a call and/or handoff call is allocated by comparing the call and/or handoff call attempt block threshold value with the forward sector excess capacity value when a certain mobile unit requests a call allocation.

Abstract: A method for using a mobile switching center (MSC) having a large capacity, particularly a method for using a MSC such that many service providers can use the MSC in common, comprises confirming a caller group to which a corresponding caller belongs by checking a number when a call is initiated from the caller, receiving a called number, authenticating and authorizing the caller, and processing the caller and the call according to the caller group to which the caller belongs. When the authentication and authorization succeed, the process searches for a predefined greeting announcement for the particular caller group and, if one is found, connects the predefined greeting announcement to the caller. The process also determines according to the caller group whether a certain trunk should be used and, if so, connects the call to that trunk.

Abstract: A phase compensation apparatus and method for a digital modulator which is suitable for maintaining the optimum operating state of the modulator provided in a digital television repeater by reducing the phase distortion produced from the modulator.

Abstract: An automatic compensation circuit for so-called “no margin input data” comprises no margin detecting means for receiving input data and detecting whether the input data has no margin by detecting whether the input data overlaps a clock, and no margin compensating means for compensating for a lack of margin between the input data and the clock by selecting either the input data or data having a proper margin with respect to the clock according to the result of the no margin detecting means.

Abstract: The present invention provides data transmission control system in Set Top Box STB capable of matching output timings of a video or audio signal and a synchronous signal of the video or audio signal by controlling the transmission of the data bitstreams when transmission paths of video data or audio data and the synchronous signal of the video or audio data, are different from each other. Therefore, it is capable of solving the problems generated by asynchronization of a presentation signal. The present invention provides the video data transmission control system in Set Top Box(STB), comprising a bitstream control means in a data transmission path for matching timings of the bitstream ES(Elementary Stream) and a Presentation Time Stamps(PTS), in which the PTS and data ES are selected from compressed data ES respectively, which are transmitted for dynamic image presentation, decoding the ESs according to the PTS, and applying the decoded ES to an output device on the data transmission path.

Abstract: A cellular radio communication system having base stations constructed in the form of a daisy chain and a method of controlling data transmission using the system whereby data communications with a plurality of base stations as well as data communications among the respective base stations can be performed using a single base station controller and shared transmission lines in a specified area wherein expressways or railroads are constructed. The system includes a base station controller provided in a specified region of a determined service area, and a plurality of base stations linked in series to the base station controller through trunk lines.

Abstract: An ATM cell converting apparatus and method provided with a tone and DTMF generating function generates tone and DTMF which are necessary to a switching system and outputs to a TDM network channel data of an ATM cell type which are read from a cell buffer of a memory unit or tone and DTMF which are read from a tone and DTMF register in accordance with a function type of a data converting unit.

Abstract: An active distortion signal generating circuit for removing linear distortions in a power amplifier includes a linear processing circuit that receives a linear path signal and outputs a linear signal; a nonlinear processing circuit that receives a nonlinear path signal and outputs a distortion signal; and an output circuit that adds the linear signal and the distortion signal to obtain a first sum signal, that adds the first sum signal to a duplicate first sum signal to obtain a second sum signal and that generates control signals utilizing the linear signal, the distortion signal, the first sum signal and the second sum signal; and a variable attenuator and phase shifter that adjusts the distortion signal based upon the control signals. The active distortion signal generating circuit compensates the amplitude and phase errors of the input signal such that no input signal component appears at the output of the active distortion signal generating circuit.

Abstract: A U-interface matching circuit and matching method is disclosed. The circuit includes a plurality of BRI (Basic Rate Interface) boards implementing a digital subscriber's matching, a control board controlling operating modes of the plurality of BRI boards and an SA (Serial Access)-bus providing an independent data transmission path with regard to the plurality of BRI boards. The method includes a first step identifying mounting locations of a plurality of BRI boards, a second step reading an RX flag area of a first BRI board for data transmission and identifying whether the read RX flag is a flag representing the access complete of the first BRI board, a third step setting the first BRI mode as a write mode and transmitting the data length value and transmission data when the RX flag is a flag representing an access complete of the first BRI board, and a fourth step receiving transmission data of the first BRI board.

Abstract: Device and method for decorrelated multiuser detection in a DS-CDMA system, is disclosed, which allows real time removal of an MAI(Multiple Access Interference) occurred in the DS-CDMA system, the method including the steps of(a) receiving signals band spread by multiuser spreading codes transmitted from multiuser respectively and despreading the received signals with conjugate complexes of the multiuser spreading codes, to restore each of multiuser messages y, (b) spreading each of the multiuser messages with the multiuser spreading codes, summing, despreading with the conjugate complexes of the multiuser spreading codes, low pass filtering, and subtracting from the multiuser messages y under bit synchronization, for extracting multiple access interference signals Qy according to cross-correlation coefficients between the multiuser spreading codes contained in each of the messages y; for the first time, and (c) adding negative values of the multiple access interference signals Qy extracted in the step (b) to

Abstract: A transmitting and receiving antenna VSWRs (voltage standing wave ratio) measuring circuit of a base station in a mobile communication system comprises: transmitting and receiving antennas for transmitting and receiving a radio frequency signal of a predetermined frequency band in a mobile communication system; transmitting antenna VSWR measuring means for variable-attenuating and detecting a transmitting signal received from the transmitting antenna and sending a transmitting signal strength to a measuring controller whereby to measure transmitting power and reflected power; and receiving antenna VSWR measuring means for variable-attenuating and detecting a receiving signal received from the transmitting antenna and sending a receiving signal strength to a measuring controller whereby to measure receiving power and reflected power.

Abstract: The scaleable CDMA communication system comprises a new spreading code operating at an increased chip rate. The chip rate is selected to be a multiple of a base chip rate, and the new spreading code is created by repeating a base spreading code. Synchronization frames are thereby consistent with established CDMA communication systems. After spreading, a periodic phase rotation is applied to the communication signals, thereby providing a synchronization marker. The phase rotation and resulting synchronization marker enables subscriber units to synchronize to system timing with a minimum of ambiguity.

Abstract: A system for sensing the operating state of a tower top amplifier for mobile communication system, includes a plurality of tower top amplifiers each connected to communication antennas; and an operating state management part monitoring the operating state of each tower top amplifier. The operating state management part monitors the operating state of each tower top amplifier by the use of a single power supply line connected between itself and each tower top amplifier. In a method of sensing the operating state of a tower top amplifier for mobile communication system, the operating state of each tower top amplifier is monitored by using an amount of consumed DC power applied to the respective tower top amplifiers. This method includes the steps of measuring a potential difference of a given section of the DC power applied to each tower top amplifier; and comparing a result obtained by the measuring step and determining the normal or abnormal states of the tower top amplifiers.

Abstract: A method of managing overload of messages in communication systems comprising: classifying application processes according to use/non-use of messages and scales and types of overload and constructing a database based upon a result of classification; periodically checking message queues of said application processes to identify states of the message queues; and when the state of one of said message queues is an advanced overload state, analyzing a scale and type of relevant overload using said database and processing the overload analyzed.

Abstract: A self-checking circuit in a microwave equipment comprising: directional couplers each for separating and extracting a portion of a microwave signal from each monitoring point on a microwave main signal path; detectors each for detecting an extracted signal from the directional coupler; multiple temperature measuring means each for measuring temperature of the detector; multiple amplifying means each for amplifying a detected signal from the detector; multiple analog/digital converting means each for converting an output signal of the amplifying means into digital data; an interface for performing interface with an outside with respect to the signal of the temperature measuring means and the digital data of the analog/digital converting means; first storage means for storing signal values transmitted through the interface; second storage means for storing a control program and various data; a central processing circuit for comparing and analyzing the signals stored in the first storage means using the control

Abstract: An apparatus and method for controlling power in a CDMA system using antenna diversity. The power control apparatus comprises a CDMA base band/IF transmitter for processing an information signal to output K IF signals, K RF modules for converting the K IF signals from the CDMA base band/IF transmitter into K RF signals and transmitting the converted K RF signals through K transmitting antennas, a receiver for receiving a signal from a mobile terminal through a receiving antenna and processing the received signal to output K power control bits and decoded data, and a processor for generating K data channel gains in response to the K power control bits from the receiver and outputting the generated K data channel gains to the CDMA base band/IF transmitter to control transmission powers of the K transmitting antennas.

Abstract: The present invention is to provide a phase compensation circuit of a DPPLL capable of hitless switching during switching the system clock, by exact matching frequency and phase of the DPPLL about phase difference which is less than minimum differential phase which may be detectable the way of digital and by distinguishing phase difference about the other party clock such that each clock unit commonly has the clock generated from the pair of clock units, alternatively and by switching the system clock in case that there is no difference after distinguishing, in the clock supplying system using the pair of lock units which have the phases that is asynchronized to the reference clock.