Abstract:
본 발명은 다수의 송수신 안테나를 갖는 직교주파수 분할 다중 접속 시스템에서 효율적인 신호 수신 장치 및 방법에 관한 것이다. 본 발명은 미리 설정된 일부의 데이터스트림을 다차원 수신과정에 따라 복조하는 단계; 상기 복조된 데이터스트림에 대응하는 심볼을 재발생하는 단계; 나머지 데이터 스트림으로부터 상기 재발생된 심볼을 제거하는 단계; 상기 재발생된 심볼이 제거된 나머지 데이터 스트림을 복조하는 단계; 및 상기 다차원 수신과정에 따라 복조된 데이터 및 상기 복조된 나머지 데이터 스트림을 직렬변환하여 출력하는 단계;를 포함하는 다수의 송수신 안테나를 갖는 직교주파수 분할 다중 접속 시스템의 신호 수신 방법을 개시한다. MIMO, 다차원 수신기, MIMO-OFDM
Abstract:
A method and a device for estimating a CINR(Carrier to Interface and Noise Ratio) at an OFDM(Orthogonal Frequency Division Multiplex) are provided to estimate accurately the CINR by using a preamble. A transmitting sub-carrier interference and noise estimator estimates transmission sub-carrier interference power and transmission sub-carrier noise power by using a received preamble symbol or a sub-carrier. A receiving power estimator(1014) produces the receiving power for transmitting the preamble symbol and a data symbol. A noise/interference power estimator(1016) produces noise power and interference power by using one or more of a sub-carrier without transmitting the preamble symbol, a Null sub-carrier or a sub-carrier not to be assigned to a receiver related to a different base station. A CINR estimator(1018) estimates a CINR value of a preamble by using the noise power, the interference power, and the receiving power. A data sub-carrier CINR estimator(1020) estimates a CINR of a data region by using a preamble CINR value and the noise power or the interference power estimated by the noise/interference estimator.
Abstract:
본 발명은 직교 주파수 분할 다중(OFDM) 시스템에서 시변 채널에서의 채널 추정 방법에 관한 것이다. 본 발명은 시변 채널을 추정하기 위해서 프리앰블(Preamble)을 이용해 얻은 채널의 초기치를 이용한다. 이와 같이 하면, 간단하면서도 빠르게 시변 채널을 추정할 수 있으며, 시간축에서 채널을 추정함에 따라 잡음을 줄이는 효과를 볼 수 있어 추정 성능이 향상된다. OFDM, 채널 추정, 시변 채널
Abstract:
본 발명은 직교주파수 분할 다중 접속(Orthogonal Frequency Division Multiple Access, OFDMA) 방식을 사용하는 이동형 데이터 통신 시스템의 하향 링크 프레임 구조 설계에 이용될 수 있는 OFDMA 신호 방식을 위한 하향 링크 프레임 구성 방법에 관한 것이다. 이 하향 링크 프레임을 구성하기 위해 먼저 하향 링크 프레임의 앞부분에 하나의 프리앰블을 배치하고, 프리앰블 다음에 복수의 데이터 심벌을 배치한다. 다음, 하향 링크 프레임 전반에 걸쳐 일정 구간 주기로 반복해서 상기 데이터 심벌들 사이에 복수의 파일럿 심벌을 삽입한다. 본 발명에 따르면, 프리앰블과 파일럿 심벌을 이용한 빠른 채널 변화를 추적 가능하게 하며, 또한 인접 셀 간의 간섭이 최소화 및 평준화되도록 함으로써 주파수 재사용률을 1로 하여 다수의 셀의 배치 설계를 용이하게 할 수 있다.
Abstract:
PURPOSE: A method and an apparatus for transmitting and receiving TDMA(Time Division Multiple Access)/OFDM(Orthogonal Frequency Division Multiplexing) system are provided to improve transmission speed by selecting one pilot pattern depending on terminal environment. CONSTITUTION: A pilot pattern controller(61) selects one out of plural pilot patterns and determines the number of data sub-carrier, pilot sub-carrier and the position of an input terminal of an IFFT(Inverse Fast Fourier Transform) unit(67). A serial/parallel converter(62) converts high-speed transmission data being received in serial into low-speed parallel data based on the determined number of data sub-carrier, and a pilot being received in serial into parallel based on the number of pilot sub-carrier. A modulator(64) modulates the converted data and pilot according to a predetermined modulation. A parallel/serial converter(68) converts an OFDM symbol of a parallel signal into a serial signal to output. A CP(Cyclic Prefix) is additionally inserted into the parallel signal. A D/A(Digital/Analog) conversion and filter(69) converts a digital signal into an analog signal and filters the analog signal to transmit it to a receiver(70) through the RF(Radio Frequency) terminal.
Abstract:
PURPOSE: An interleaving/deinterleaving device in a communication system using channel reciprocity is provided to transmit bits having high priorities to a part where delay between an uplink and a downlink is small, and to transmit bits having low priorities to a part where the delay is big, thereby reducing error rates of the bits having the high priorities. CONSTITUTION: An encoder(31) encodes inputted data bits. Interleavers1 and 2(32,33) distinguish the encoded bits into bits having high priorities and bits having low priorities, and interleave the distinguished bits, respectively. A multiplexer(34) multiplexes the encoded bits having the high priorities in a part highly correlated to an uplink, and multiplexes the bits having the low priorities in a part lowly correlated to the uplink. A modulator(35) modulates the bits multiplexed through the multiplexer(34).
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.