Abstract:
본 발명은 정 포락선 부호화를 사용한 코드선택 코드분할 다중접속 통신 시스템에서 상관기 출력과 패리티 검사 결과를 이용한 수신 신호의 복조 방법 및 그 장치에 관한 것으로, 보다 자세하게는 잉여 블록의 정보를 활용하여 정보비트의 오류를 정정함으로써 시스템의 비트오율 성능을 개선시키는 코드선택 코드분할 다중접속에서의 복조 방법 및 그 장치에 관한 것이다. 본 발명의 정 포락선 부호화를 사용한 코드선택 코드분할 다중접속 통신 시스템에서 상관기 출력과 패리티 검사 결과를 이용한 수신 신호의 복조 방법은 정 포락선 부호화를 사용한 코드선택 코드분할 다중접속 통신 시스템의 수신 신호의 복조 방법에 있어서, 입력되는 수신 신호를 4개의 블록을 가진 코드선택 코드분할 다중접속 복조기에서 복조하는 단계; 복조된 비트열에 대해 n(n≤N, N은 정보채널수)번째 위치의 4개 비트들의 패리티 검사를 수행하는 단계 및 상기 패리티 검사 결과를 이용하여 출력 신호를 결정하는 단계로 이루어짐에 기술적 특징이 있다. 따라서, 본 발명의 정 포락선 부호화를 사용한 코드선택 코드분할 다중접속 통신 시스템에서 상관기 출력과 패리티 검사 결과를 이용한 수신 신호의 복호화 방법 및 그 장치는 수신기에서 송신기의 신호를 일정 펄스폭으로 만들고 기존의 수신기에서는 사용하지 않는 잉여 블록의 정보를 활용하여 정보비트의 오류를 정정함으로써 시스템의 비트오율 성능을 개선할 수 있으며, 주어진 품질을 얻기 위하여 필요한 송신 에너지를 감소시킬 수 있어 에너지 효율이 향상되는 효과가 있다. 또한 코드선택 코드분할 다중접속에서 포함하고 있는 레벨 클리핑 과정을 제거할 수 있어서 채널간 직교성의 손상 문제가 없고 전력 증폭기의 선형성이 요구되지 않는 효과가 있다. 코드선택 코드분할 다중접속, 직교코드, 오류정정
Abstract:
시스템의 소비전력이 낮고, 저렴하게 전력 증폭기를 제조할 수 있으며, 간섭의 강인성을 확보하며, 대용량의 전송률과 가변 전송률로 데이터를 전송할 수 있으며, 변조시 패리티 비트를 이용하여 오류를 정정한다. 정 진폭 이진직교 변조장치는, 직렬 데이터를 복수 군의 데이터 비트로 변환하고, 복수 군의 데이터 비트를 각기 조합하여 각각의 군의 패리티 비트를 발생하며, 복수 군의 데이터 비트와 각 군의 패리티 비트에 따라 복수 군의 직교코드들 중에서 각기 하나의 직교코드를 선택하고 부호를 조절하여 이진직교 변조한 후 병렬로 합산하여 정 진폭 이진직교 변조된 데이터를 발생하며, 정 진폭 이진직교 복조장치는 수신되는 정 진폭 이진직교 변조 데이터를 복조하고 패리티 비트를 제거한 후 직렬 데이터를 생성하고, 복조한 데이터를 복수의 군으로 구분하여 에러 발생을 검출하고 에러가 발생되지 않았을 경우에 상기 직렬 데이터가 복조 데이터로 출력하며, 에러를 검출될 경우에 에러가 발생한 군의 데이터의 비트 부호를 순차적으로 변환하면서 변조 및 수신되는 이진직교 변조 데이터와 디스턴스를 비교하여 비교 결과에 따라 해당 비트 부호를 변경한 데이터를 복조 데이터로 선택한다.
Abstract:
An apparatus for transmitting data in a wireless communication system is disclosed. An apparatus for transmitting data in a wireless communication system according to the present invention includes a serial to parallel converter operable to transform serial data into parallel data; a summer operable to combine the parallel data after multiplying them by orthogonal code; a level clipper operable to remove a portion of the summed signal above and below a desired threshold range; and a quadrature phase shift keying(QPSK) modulator operable to change the phase of the clipped signal and to transfer the modulated signal therefrom. Thus, the present invention can embody high-speed data transfer rate in such a simple structure by combining a VSG method with an MC method to clip multi-level signals from the MC method and to maintain orthogonality of MC required in the VSG method.
Abstract:
PURPOSE: A method for selecting packets according to a channel environment in a local area wireless PAN system is provided to satisfy a required peak throughput and a packet error rate by selecting packets corresponding to a channel state without lowering data transmission rate and spectrum efficiency. CONSTITUTION: One packet is exchanged between a master slot and a salve slot. The packet of a Bluetooth system is formed of an access code, a packet header, and a payload. A bit error rate is measured by the access code of the transmitted packet. A state of the channel is predicted by the measured bit error rate. The packet is selected by considering throughput and transmission delay of the Bluetooth system according to the predicted state of the channel.
Abstract:
PURPOSE: An improved method for estimating a frequency offset of a mobile communication system is provided to obtain a diversity gain and improve the accuracy of the frequency estimation by combining estimated values of each frequency offset. CONSTITUTION: An estimating process of frequency offset is performed in each sub channel, respectively. A frequency offset combination process is performed to combine the estimated values of each frequency offset. A mobile communication system is formed with a multi-input/output channel modulation system, a transmission diversity system, a multi-code division multi-access system or a binary code division multi-access system. The multi input/output channel modulation system or transmission diversity system perform a frequency offset estimation process by using a predetermined mathematical expression.
Abstract:
PURPOSE: A method for interpolating a frequency and a phase offset to improve resolution of DFT(Discrete Fourier Transform) and FFT(Fast Fourier Transform) is provided to improve the frequency of DFT algorithm and the phase resolution without increasing a DFT size by using an internally dividing point. CONSTITUTION: A sampling process is performed to sample received signals according to a predetermined period(101). The received data stream is converted to a frequency area to obtain a frequency spectrum(102). Two continuous samples having the maximum sum are selected from continuous samples of the frequency area(103). A fine frequency offset is estimated by using an internally dividing point of the selected samples(104). A total frequency offset is obtained by adding a coarse frequency offset to the estimated fine frequency offset(105).
Abstract:
PURPOSE: A device for transmitting data in a wireless mobile communication system is provided to clip a multi-level signal generated in an MC(Multi Code) system by combining a VSG(Variable Spreading Gain) system with the MC system, and to maintain MC orthogonality, thereby implementing high speed transmissions. CONSTITUTION: A serial/parallel converter(100) converts serial data into parallel data. An adder(102) multiplies the parallel data by an orthogonal code, and adds code signals. A level clipping unit(104) clips a signal more than a certain level among the added code signals. A QPSK modulator(106) transmits residual level signals remaining by a clipping operation of the level clipping unit(104) via a QPSK process. A data transmission device clips a multi-level signal generated in an MC system by combining a VSG system with the MC system, and maintains MC orthogonality requested in the VSG system.
Abstract:
PURPOSE: A device and a method for an education service through a physical growth model using the Internet and the wireless communication are provided to enhance the interest and the learning concentration of child by constructing a robot base, a house, and a castle gradually according to a learning step, and giving a gift as completing the growth model when a final education object is reached. CONSTITUTION: A learning data storing part(250) stores the learning data. An education part(230) performs the gradual education according to a preset learning step. A test part(240) performs a test after finishing the education of the education part(230), and elevates the learning step by one step according to a test result. A controller(220) outputs a control signal to grow the physical growth model according to the learning step, and transfers the gift if the learning step passes a final learning step. A gift giving device(400) grows the physical growth model and gives the gift according to the control of the controller(220).
Abstract:
PURPOSE: A home RF system using channel estimation and DC offset compensation methods is provided to estimate a channel by using a TS(Training Sequence) field and a decision feedback method of a PDU, and to compensate for a DC offset by using the TS, thereby improving performance. CONSTITUTION: A transmission unit comprises as follows. A scrambler(100) changes a frequency. A symbolizer(200) symbolizes a bit-unit signal. An encoder(300) encodes a transmission signal. A TS field adder(400) adds a TS field to the transmission signal. An FSK(Frequency Shift Keying) modulator(500) changes a frequency of a high frequency current into a signal. A receiving unit comprises as follows. An FSK demodulator(600) compensates a DC offset. A decoder(700) decodes the encoded signal. A desymbolizer(800) desymbolizes the symbolized signal. A descrambler(900) restores the changed frequency.
Abstract:
PURPOSE: An apparatus for compensating a channel distortion in a WPAN(Wireless Personal Area Network) is provided to compensate channel distortion phenomenon by multiplying a signal received from a transmission side by a channel estimation value and recovering a phase component distorted on a channel. CONSTITUTION: A phase recovering block(10) multiplies a channel of a signal transmitted from a transmission-side modulating device by an estimation value and recovers a phase component distorted on a signal channel. A codeword correlator block(20) multiplies the signal recovered by the phase recovering block(10) by a complex codeword and obtains a decision variable through a correlation process during a symbol period. A maximum correlation detecting block(30) selects a correlation value having a maximum level from the decision variable outputted by the codeword correlator block(20), and decodes data with 6 bits according to the correlation value with the maximum value. A complex polarity detecting block(40) detects a phase using the combination of the polarity of the maximum correlation value detected by the maximum correlation detecting block(30), and decodes data with 2 bits according to the correlation value with the maximum value. A channel estimation block(50) performs a channel estimation using one codeword for generating the maximum correlation value selected by the maximum correlation detecting block(30) and the phase selected by the complex polarity detecting block(40). A receipt-side multiplex(60) combines the data with 6 bits decoded by the maximum correlation detecting block(30) with the data with 2 bits decoded by the complex polarity detecting block(40) to recover the data, and converts the recovered parallel data with 8 bits into serial data.