Abstract:
A digital communication method and a system for the same are provided to reduce the number of puncturing by subdividing a method of processing during a multi-dimension orthogonal resource hopping pattern collision. A digital communication method includes the steps of: measuring a transient collision ratio at a specific frame of a multi-dimension hopping pattern; and stopping a frame transmission in order of a less affective channel if the transient collision ratio becomes higher than a reference collision ratio.
Abstract:
PURPOSE: A wireless connection device for a multimedia service and a method therefor are provided to construct a TDD(Time Division Duplex) type wireless private network in a limited area using one public communication portable phone and receive a voice telephone call and an Internet service using the wireless private network. CONSTITUTION: A channel management device(210) initializes mobile terminals(110,120,130), transmits and receives subscriber association information with the mobile terminals(110,120,130), and processes the access and paging of the mobile terminals(110,120,130). A wired network interface device(220) connects to an external network and converts a signal transmitted and received to a TDD type mobile terminal. A system control unit(230) connects to the channel management device(210) and the wired network interface device(220), processes a call, manages the registration and state of subscribers, and manages and controls each device.
Abstract:
PURPOSE: A device for estimating a channel in a time division bidirectional communication system is provided to use a channel estimating method from a chip unit, a symbol unit, and a time slot, thereby minimizing an error caused during channel estimation. The device is provided to use a simple averaging method, thereby reducing random FM phenomenon caused by a channel estimating error. CONSTITUTION: A converter(100) receives a transmitted RF signal, and converts the signal into a baseband signal. A matching filter(200) filters the converted signal. A multiplier(300) multiples a signal sampled by a sampling period with chip units from the filtered signal by a midamble sequence for I and Q codes. An adder(400) adds signals as many as all midamble chips from the multiplied signal. An accumulator(500) divides the added signals as many as the number of the midamble chips, and obtains an average value. A channel estimating calculator(600) calculates a channel estimating value through consecutive two time slots or one-time slot from output values of the accumulator(500).
Abstract:
PURPOSE: A rate matching apparatus of a data communication system and a method thereof are provided to match channel-encoded symbols with a transmission rate appropriate for a physical layer to transmit. CONSTITUTION: According to the rate matching apparatus in a digital communication system, a channel encoder unit(220) performs a channel encoding as to input information bits. A multiplexer unit(260) performs a time division multiplexing as to symbols channel-encoded by the above channel encoder unit regularly. A parameter converter unit(1440) provides input parameter value required in the transmission rate matching. And a transmission rate matching unit(1430) reproduces symbols as much as appropriate for a physical layer by puncturing or repetition as to multiplexed channel encoded symbols and then matches them with a transmission rate appropriate for the physical layer to transmit, according to the above input parameter value.
Abstract:
PURPOSE: A reference signal generation device and a method therefor and a smart antenna base station system based on chip level beam former using the same and an operating method therefor are provided to generate a reference signal according to a channel estimator and a chip level beam former by using a decision-directed mode, thereby increasing system capacity and base station ranges by exactly performing channel estimating and beam forming processes. CONSTITUTION: An RF receiver(102) converts a received signal into a digital baseband signal. A multi path searcher(103) inputs the digital baseband signal to detect multi paths, and estimates delay time for the multi paths. A chip level beam former(105) calculates a chip level beam forming weight vector, and multiplies the vector to an input signal vector of an array antenna(101). A despreader(106) performs despreading processes on the multi paths, and separates a DPDCH(Dedicated Physical Data Channel) from a DPCCH(Dedicated Physical Control Channel). A channel estimator(107) estimates channels up to the array antenna(101). A channel compensator(108) compensates DPDCHs and DPCCHs of each rake finger(104). A rake synthesizer(109) synthesizes the DPDCHs with the DPCCHs. Deciders(DPDCH,DPCCH)(110) decide symbols of the DPDCHs and the DPCCHs. A reference signal generator(111) generates a reference signal.
Abstract:
PURPOSE: A down link beam forming system and a method thereof are provided to transmit a maximal power to a direction in which a desired terminal is located using a receiving array response vector obtained in a uplink. CONSTITUTION: An adaptive array modulator(105) generates a reference signal necessary to estimate a receiving array response vector. A correlator(106) estimates the receiving array response vector by obtaining an average with respect to a time of a signal obtained by multiplying the reference signal by digital receiving data. A transmission beam form weight calculator(110) removes an uplink channel component from the receiving array response vector to obtain a receiving antenna response vector. The transmission beam form weight calculator(110) calculates a transmission beam form weight using the receiving antenna response vector. A down link beam form device(107) multiplies the beam form weight by a user signal to perform a down link beam form function.
Abstract:
본 발명은 소프트 핸드오프 성공률을 높이고, 안테나 이득을 증대시킬 수 있는 코드 분할 다중 접속 방식(CDMA) 이동 통신 시스템의 섹터 안테나 시스템을 제공하는데 그 목적이 있다. 본 발명에 따르면, 다수의 섹터로 분할된 셀 구조를 가지는 코드 분할 다중 접속 방식(CDMA) 이동 통신 시스템의 섹터 안테나 시스템에 있어서, 상기의 섹터 안테나 시스템은 다수의 안테나 센서를 포함하는 선형 배열 안테나(Linear Array Antenna)를 포함하고; 상기 인접하는 안테나 센서간의 거리는 소프터 핸드오프(Softer Handoff)가 발생하는 빔의 중첩 각도를 고려하여 결정하는 것을 특징으로 하는 섹터 안테나 시스템이 제공된다.
Abstract:
PURPOSE: A finger, a space-time array receiving system having the same, and a method for compensating a distortion by a fading channel are provided to adaptively compensate a distortion state due to a fading channel by adding a Doppler frequency estimator and a correlation length selector and to increase communication quality, a service coverage per base station, and subscriber capacity by using a chip level and time reference beam forming technique. CONSTITUTION: A space-time array receiving system having a finger(430) consists of a digital beam forming network(400), a demodulator(430), a rake combiner(430-D), a hard limiter(440-B), and a reference signal generator(440-A). The digital beam forming network(400) is composed of multipliers(400-A) and an adder(400-B). The demodulator(430) demodulates the output signal of the digital beam forming network(400). The rake combiner(430-D) receives the output signal of the demodulator(430) and combines symbols. The hard limiter(440-B) executes hard decision for the signal passing through the rake combiner(430-D). The reference signal generator(440-A) receives the information fed back from the finger in the demodulator(430) and the output of the hard limiter(440-B) and creates a reference signal. The finger in the demodulator(430) comprises a Doppler frequency estimator(430-F) and a correlation length selector(430-E). The Doppler frequency estimator(430-F) receives the fading channel information of a pilot channel I/Q correlator(430-A) and estimates a fading channel Doppler frequency. The correlation length selector(430-E) receives the estimated fading channel Doppler frequency and estimates the correlation length of the pilot channel I/Q correlator(430-A).
Abstract:
PURPOSE: A sector antenna system of the CDMA(Code Division Multiple Access) mobile communication system is to provide a sector antenna system to proceed more efficient soft hand-off, by optimizing the cell structure divided into a plurality of sectors. CONSTITUTION: The cell structure divided into three sectors in the CDMA system is composed of four cells(A,B,C,D) and two mobile stations(100,101). Incident angles for each cell are same(alpha1 = alpha2 = alpha3) in a point(102) the boundary lines of three cells meet. But, in other boundary point(103), except for the boundary point(102), incident angles for each cell are all not in accord.
Abstract:
PURPOSE: A sector antenna system of a CDMA mobile communication system is provided where distance between antenna sensors is optimized. CONSTITUTION: A sector antenna system of a CDMA mobile communication system increases the success rate of soft handoff, and increases the antenna gain. The sector antenna system has a cell structure divided into a number of sectors, and includes a linear array antenna including a number of antenna sensors, and the distance between the adjacent antenna sensors is determined by considering an overlapping angle of a beam generated by a softer handoff.