Abstract:
본 발명은 이중 STBC-OFDM 방식의 MIMO 시스템에서 수신 신호를 검파할 때, 선형 방식과 비선형 방식을 함께 사용하여 연산 복잡도를 낮추면서도 검파 성능을 향상시킬 수 있는 수신 장치 및 그 방법에 관한 것으로, 다중입력 다중출력(MIMO) 시스템의 수신 장치에 있어서, 수신 신호 벡터에 대한 단일(Q) 행렬 벡터와 상삼각(R) 행렬 벡터를 계산하는 QR 분해수단; 상기 QR 분해수단에 의해 계산된 Q 행렬 벡터와 R 행렬 벡터를 이용해 일부 심볼을 추정하는 제1 심볼 추정수단; 상기 제1 심볼 추정수단에 의해 추정된 일부 심볼에 대한 비트 단위 로그 우도율(LLR)을 계산하는 LLR 계산수단; 상기 LLR 계산수단에 의해 계산된 로그 우도율을 이용해 디코딩된 신호를 입력받아 상기 수신 신호 벡터에서 간섭을 제거하는 간섭 제거수단; 및 상기 간섭 제거수단에 의해 간섭이 제거된 신호에 대해 선형적으로 나머지 심볼을 추정하는 제2 심볼 추정수단을 포함한다. MIMO, 다중, 안테나, 입력, 출력, 수신, 선형, 비선형, QR, 분해, 간섭, 제거
Abstract:
PURPOSE: A method and a device for transmitting and receiving packet capable of detecting system of data are provided to conveniently perform system detection about data transmitted by a new system and maintain compatibility about existing system at the same time. CONSTITUTION: A pattern decision unit(506) determines a pattern of a real number part and an imaginary number part corresponding to a system about transmitting data. A transmitting unit(508) transmits subcarrier according to combination of the determined real number part and imaginary number part. A receiving unit(512) receives the subcarrier through the transmitting unit of a packer transmitting unit(502). A system decision unit(510) determines system data received by the received subcarrier.
Abstract:
PURPOSE: A packet transmit-receive method and an apparatus capable of recognizing a termination of the packet are provided to accurately recognize the termination of the packet without loss of a packet throughput by detecting additional data including termination information of the packet. CONSTITUTION: A packet end training preamble(202) showing a termination of corresponding packet is inserted into the packet used to existing OFDM system. A length of the packet is increased by inserting the packet end training preamble into the packet. The increase of the packet length not brings the loss of a packet throughput. A packet transmission method includes a step inserting an additional data to the packet including the preamble for a data and the data. The packet transmission method includes the step of transmitting the packet and the additional data. The additional data includes termination information of the packet.
Abstract:
An apparatus and a method for reducing degradation of a synchronous performance due to difference of a time response generated between receiving antennas are provided to efficiently perform symbol synchronization by preventing a violation of a protective section. A channel power calculating part calculates(1110) a channel power from receiving signals(1171-1179) according to antennas of a first frequency band, receiving signals(1181-1189) according to antennas of a second frequency band, and receiving signals(1191-1199) according to antennas of an mth frequency band. An average calculating part calculates(1120) an average of a channel power value about a selected antenna. A frequency correcting part corrects(1130) a carrier frequency offset. A symbol boundary determining part determines(1140) a symbol boundary by using a frequency corrected value. A logic operating part detects symbol synchronization of whole system receiving signals by performing a logic operation(1150) about the determined result.
Abstract:
An effective bit calculating method used with a soft-decision decoding apparatus for improving performance while reducing the implementation complexity in a multi input multi output system and a method thereof in a multi input multi output system and a method thereof are provided to maximize channel decoding performance. One or more multiplier multiplies the soft demapper signal according to a modulation mode by the size shape value of the null matrix vectors outputted from the detector. An effective bit calculator(302) deletes a part of the lower bit about the output bit of the multiplication method and extracts the effective bit. The effective bit calculating unit compares the absolute value and threshold value of the rest bit. According to the comparison result, the definite value is set up as the upper bit or rounds in the number corresponding to the specific bit.
Abstract:
본 발명은 다중 모드 무선랜을 위한 적응형 전압 참조값을 갖는 자동 이득 조절 장치 및 방법에 관한 것이다. 다중 안테나를 이용하는 무선 통신 시스템에서 자동 이득 조절 장치로 입력된 수신 신호의 모드에 따라 최적의 전압 참조값 즉 목표 이득을 산출하고, 산출된 목표 이득과 수신 신호의 전력 크기를 토대로 수신 신호의 이득을 조절한다. 따라서 다중 모드별로 각 모드에 최적의 목표 이득 값을 사용하여 이득을 조절하기 때문에, 모든 모드에서 가장 좋은 성능을 유지하도록 이득을 조절할 수 있으며, 최적의 수신 성능을 보장할 수 있다. 자동 이득 조절, 적응형 전압 참조값, 다중 안테나, 무선 랜, 목표 이득 값
Abstract:
A method and an apparatus for receiving signals of a wireless communication system are provided to accomplish a high transmission rate and high link level performance by detecting received signals by using a linear equalizer in a ZF(Zero Forcing) manner and applying a weight value according to noise amplification, and reduce complexity of a receiving end. A receiving end receives signals via reception antennas(S311). CPRs(CP Removers) remove CPs(Cyclic Prefixes) the received signals and input them to FFTs(Fast Fourier Transformers). The FFTs perform FFT on the outputs of the CPRs(S312). The reception signals are converted into reception vectors(S313). An inverse matrix of an effective channel matrix of the received signals is obtained and applied to a ZF equalizer(S314). The ZF equalizer multiplies the inverse matrix of the effective channel matrix to the reception vector(S315) to detect signals(S316).
Abstract:
An apparatus and a method for automatically controlling a gain having an adaptive voltage reference value for a multi-mode WLAN(Wireless LAN) are provided to control a gain to maintain the best performance in every mode and guarantee an optimum reception performance. A target gain detector(600) stores target gain information corresponding to a plurality of first signals inputted via a plurality of antennas, and outputs the target gain information based on signal modes corresponding to the respective first signals. An RF(Radio Frequency) receiving unit(100) receives the plural first signals via the plural antennas and controls gains with respect to the plurality of first signals based on the target gain information to output a plurality of second signals. If the number of second signals greater than a pre-set threshold value is more than a certain number, a signal saturation detecting unit(400) outputs a saturation state index determination value. An AGC(Automatic Gain Controller)(300) compares each power of the plural second signals, detects one power, and outputs a gain value determined based on the detected power and the saturation state index determination value to the target gain detector. A variable gain amplifier(120) which an LNA(Low Noise Amplifier)(121) and a VGA(Variable Gain Amplifier) module(122) adds gain to an RF signal inputted from each RF receiver(110) to amplify the RF signal which consists of an in-phase(I) signal and an orthogonal phase(Q) signal.
Abstract:
A wireless LAN transmitting/receiving OFDM(Orthogonal Frequency Division Multiplexing) system for providing an extended service coverage and a method thereof are provided to extend a coverage with maintaining interoperability with an existing system. A wireless LAN transmitting/receiving OFDM system for providing an extended service coverage includes an OFDM modulation controlling unit, a frame generation controlling unit, a buffer unit, and an OFDM modulating unit. The OFDM modulation controlling unit controls first OFDM modulation at a time of even number, and controls second OFDM modulation changing an allocation position of each sub carrier of a first modulated OFDM symbol at a time of odd number. The frame generation controlling unit controls the generation of a frame consisting of a plurality of signal fields generated according to the first OFDM modulation and the second OFDM modulation. The buffer unit stores input data by units of the first and second OFDM modulations under control of the OFDM modulation controlling unit. The OFDM modulating unit performs repeatedly the modulation by the units of the first and the second OFDM modulations stored at the buffer unit, and constitutes the repeatedly modulated OFDM symbol into a frame under the control of the frame generation controlling unit.
Abstract:
본 발명은 멀티 캐리어를 이용한 신호 송/수신 장치에 관한 것이다. 본 발명에 따른 멀티 캐리어를 이용하여 데이터를 송신하는 신호 송신 장치는 수신되는 패킷 정보 비트를 특정 부호율을 갖도록 터보 코드로 부호화한 제1심볼을 생성하는 터보 코드 엔코더; 제1 심볼에 채널 인터리빙을 수행하는 채널 인터리버; 채널 인터리빙된 제1 심볼에 스크램블링을 수행하여 제2 심볼을 생성하는 스크램블러; 제2 심볼을 수신하여 변조하는 변조부; 변조된 제2 심볼을 왈시 코드를 이용하여 확산하는 확산 모듈; 및 확산모듈로부터 출력 신호를 수신하고, 수신된 신호에 포함된 비트의 일부를 제거하여 특정 개의 제3 심볼로 생성한 후에 파일럿 삽입, 역퓨리에 변환 및 프리픽스 삽입을 수행하는 신호 발생 모듈을 포함한다. 이러한, 본 발명에 따르면, 다중 경로에 의한 신호의 왜곡을 보상할 수 있는 장점이 있으며, 주파수 선택적 패이딩(Fading) 채널에서도 통신 성능이 좋은 효과를 기대할 수 있다. 또한, 종래의 CDMA2000 1xEV-DV시스템을 쉽게 변경하여 멀티 캐리어를 이용한 송/수신 장치로 구현이 가능한 장점이 있다. OFDM, CDMA2000 1xEV-DV, 멀티 캐리어, MC, 송신장치, 수신 장치