Abstract:
PURPOSE: An apparatus and a method for processing ranging channels of an up-link in an OFDMA(Orthogonal Frequency Division Multiplexing Access) system are provided to discriminate received signals with received signal power and time delay larger than allowed threshold values in a BS(Base Station) by using ranging channels. CONSTITUTION: A linear phase multiplier(310) compensates a phase of a sub-carrier of a ranging channel signal using a specific linear phase. A ranging code correlator(320-1 to 320-N) receives the output of the linear phase multiplier and correlates the received signal with a ranging code set used for ranging. A squaring unit(330-1 to 330-N) calculates received signal power based on the output of the ranging code correlator. A comparator(340) compares the calculated received signal power with a threshold value of a specific guard interval permitted in a receiver in a base station. A linear phase generator(350) sequentially generates linear phases corresponding to time delay included in a maximum time delay and provides the result to the linear phase multiplier. The received signal power included in the specific guard interval is discriminated based on the compared result from the comparator.
Abstract:
PURPOSE: An automatic gain control device of an OFDM system having a DC offset compensation function, a controlling method thereof, and a recoding medium for storing a program including a controlling method are provided to obtain an accurate gain value by performing simultaneously a DC offset detection process and an automatic gain control process. CONSTITUTION: An RF terminal(100) is used for controlling a gain of an input signal. A first energy calculator(120) is used for calculating energy of the input signal. A first accumulator(130) is used for accumulating energy of the first energy calculator. A second accumulator(140,142) is used for producing DC offset of the input signal. A second energy calculator(150) is used for calculating energy of the DC offset. A subtracter(160,180) is used for subtracting the DC offset energy of the input signal from the energy of the input signal. A comparator is used for comparing an output of the subtracter with a particular reference value.
Abstract:
PURPOSE: A rake receiver capable of compensating channel estimation delay is provided to use a finite impulse response filter, and to install a data buffer for buffering data during channel estimation and compensation periods, thereby according a channel value by a pilot signal from a shared pilot channel or a dedicated physical control channel with demodulated data. CONSTITUTION: Many fingers(100) estimate and compensate channels by spreading receiving signals, and output symbols. A combiner(200) combines the outputted symbols. A decoder(300) decodes output data of the combiner(200). Each of the fingers(100) comprises as follows. A despreader(110) receives wireless signals including a shared pilot signal and a traffic signal, and despreads the wireless signals. A channel estimating device(A) selectively outputs a channel estimation value estimated by the shared pilot signal and a dedicated physical control pilot signal, and buffers a traffic signal of the despread signals to output the buffered signal. An multiplier(160) multiplies the channel estimation value by the buffered value, and outputs a data value whose channel influence is compensated.
Abstract:
본 발명은 직교 주파수 분할 다중 방식의 신호 송신 방법 및 이에 적용되는 장치를 개시한다. 본 발명에 따른 직교 주파수 분할 다중 방식의 신호 송신 방법은, 기지국을 디지털신호처리부(DU: Digital Unit)와 무선신호처리부(RU: Radio Unit)로 물리적인 구분을 하는 구조의 경우 디지털신호처리부(DU: Digital Unit)와 무선신호처리부(RU: Radio Unit)를 상호 연동케 하는 직렬 인터페이스 전/후로 압축 구성 및 압축해제 구성을 추가하고, 직교 주파수 분할 다중(OFDM: Orthogonal Frequency Division Multiplexing) 신호의 직교성을 보장하기 위한 주기적 전치부호(CP: Cyclic Prefix)를 신호에 삽입하는 구성을 무선신호처리부(RU: Radio Unit)에서 수행하도록 하기 위한 구성을 갖춘다. 따라서, 본 발명은 디지털신호처리부(DU: Digital Unit)와 무선신호처리부(RU: Radio Unit) 간에 송 수신되는 신호전송 효율을 향상시킬 수 있다.
Abstract:
무선 LAN 시스템에서 시그널 필드(signal field)의 채널 정보를 이용하여 채널을 추정하는 방법은 트레이닝 필드(training field)의 채널 정보를 기초로 제1 복소 저장값을 획득하는 단계; 상기 시그널 필드의 채널 정보를 기초로 제2 복소 저장값을 획득하는 단계; 상기 제1 복소 저장값 및 상기 제2 복소 저장값을 이용하여 제1 신호 및 제2 신호를 설정하는 단계; 및 상기 제1 신호 및 상기 제2 신호를 기초로 출력 신호를 생성하는 단계를 포함한다.
Abstract:
Disclosed are a receiver for receiving a data frame transmitted from a transmitter in a MIMO system and a method of operating the same. A method according to one embodiment of the present invention includes the following steps: receiving a signal field repeatedly transmitted through a frequency band applied to a transmission of a data frame; hard-deciding the signal field based on a repeated pattern of the signal field; soft-deciding the signal field by estimating a channel based on the hard-decision result; combining the soft-decision results based on the repeated pattern; and decoding the signal field based on the combination result.
Abstract:
본 발명은 신호 검출 방법 및 수신 장치에 관한 것이다. 본 발명에 따른 신호 검출 방법은 다중 입출력 안테나를 포함하는 통신 시스템의 수신 장치가 신호를 검출하는 방법으로서, 수신 신호 벡터와 채널 상태가 고려된 송신 심볼 벡터 사이의 거리의 제곱 값을 구하는 단계, 상기 거리의 제곱 값을 제1 성분 및 제2 성분으로 분류하는 단계, 상기 제1 성분을 최소화 하여 복수의 제1 연성해(soft symbol estimate)를 구하는 단계, 상기 복수의 제1 연성해를 기초로 상기 제1 성분의 해집합을 구하는 단계, 상기 제2 성분을 최소화 하여 복수의 제2 연성해를 구하는 단계, 상기 복수의 제2 연성해를 기초로 상기 제2 성분의 해집합을 구하는 단계, 그리고 상기 제1 성분의 해집합과 상기 제2 성분의 해집합을 합하여 최종 해집합을 구하는 단계를 포함한다. 디텍션, 디코딩, MIMO, likelihood
Abstract:
PURPOSE: A high efficiency envelope tracking amplifier, a method thereof, and a multi-level DC-DC converter for high efficiency envelope tracking amplifier are provided to reduce a ripple current generated from the DC-DC converter by using the DC-DC converter in multiple bits. CONSTITUTION: A baseband signal applying unit applies a baseband signal to a power amplifying unit. A signal converting unit detects an envelope signal from the baseband signal. The signal converting unit outputs a voltage according to a multilevel quantization signal by quantizing the detected envelope signal into a multiple level. A signal amplifying unit receives power from the signal amplifying unit. The signal amplifying unit amplifies the baseband signal inputted from the baseband signal applying unit. The signal converting unit quantizes the envelope signal to a K-bit(K>=2).
Abstract:
PURPOSE: An inlet distortion apparatus, inlet distortion method, system including the same are provided to constitute simplified memory polynomial models by combining basic sections according to feedback results for output signals of a non-linear apparatus. CONSTITUTION: An inlet distortion filter(1100) selects one or more basic sections of plural basic sections according to selecting values. The inlet distortion filter constitutes memory polynomial models. The inlet distortion filter distorts input signals by using the memory polynomial models. A selection module(1140) determines the selecting values according to feedback results for output signals of a non-linear apparatus(1200).