Abstract:
PURPOSE: An adaptive interference mitigating receiver for a DS/CDMA communication system using space-time block coding is provided for a quality service at a high speed by improving data detection performance in a multi-path fading channel environment. CONSTITUTION: Chip matching filters(210,220) match-filter signals received from antennas(40) on the basis of a chip period and output them. Input signal generation buffers(310,320) generate vectors corresponding to signal blocks outputted from the chip matching filters(210,220) and output them according to a symbol period. Adaptive filter blocks(410-440) filter signals outputted from the input signal generation buffers(310,320) according to a tab weight controlled by a specific period and output them. A coupler(600) couples the signals outputted from the adaptive filter blocks(410-440) and outputs it. A data determining unit(700) restores an original signal that a specific user intends to transmit by using a signal outputted by the coupler(600). A reference signal selector(800) selectively outputs either a signal outputted from the data determining unit(700) or a learn data signal. Error generation blocks(510-540) generate an error signal for controlling a tap weight used in the adaptive filter blocks(410-440) by using a signal outputted from the reference signal selector(800) and a signal outputted from the adaptive filter blocks(410-440).
Abstract:
PURPOSE: A device for removing an interference having a simple structure in a receiver of an asynchronous CDMA system is provided to pass through a position of a band spread filter by adding all reproduced signals when reproducing receiving signals for interference removing, thereby simplifying a structure of a parallel interference removing receiver. CONSTITUTION: A demodulator(170) receives a receiving signal or a residual signal from a transmitting terminal as a baseband spread signal with over-sample units, and down-samples the received signal with chip units to output a demodulated signal. A reproducer(130) decides bits of the demodulated signal, reproduces the signal through channelization and scrambling processes, and converts the reproduced signal into an over-sample unit signal and a chip unit signal to output the converted signal. An adder(151) adds up the over-sample unit signal. A raised cosine filter(153) filters the added signal to a band spread signal. A subtracter(201) subtracts the filtered band spread signal from the received signal, and outputs a residual signal. Delayers(104) delay the chip unit signal, and unite the residual signal with timing.
Abstract:
PURPOSE: A parallel-type interference eliminating method in a CDMA(Code Division Multiple Access) receiver is provided to have a fast response characteristic by minimizing a process delay time required in interference cancellation in an asynchronous CDMA receiving environment. CONSTITUTION: A channel estimator corrects amplitude and phase information of a signal in which temporal detection is completed, and acquires a reproducing signal(404). The channel estimator adds reproducing signals on a time axis same to a signal state until reproducing signals of all users are received in a time capable of using the reproducing signal(405). The channel estimator corresponds to the added signal on a time axis same to the receiving signal, subtracts signals to the time from the receiving signal, and generates a residual signal(406). If the residual signal is reached to a level capable of detecting a symbol of an other user(407), the channel estimator adds the residual signal to the generated reproducing signal, and acquires an interference cancellation signal(408). The interference cancellation signal is detected as a symbol using a matching filter and converter(409).
Abstract:
일반적으로 CDMA 시스템은 각 단말기에서 고유의 확산코드를 사용하여 동일 주파수 대역으로 송신된 신호들이 혼합되어 수신되므로, 수신신호의 역확산시 발생되는 다중 접속간섭에 의해 시스템의 성능이 저하된다. 본 발명은 코드분할다중 접속시스템의 다중접속간섭을 줄이기 위한 그룹별 병렬 간섭제거 방식에 관한 것으로, 수신신호를 그룹화하는 방법을 새롭게 고안하여 수신기의 간섭제거능력을 개선시키고자 한다. 그룹별 간섭제거기법은 신호세기에 따라 신호들을 그룹화하여 신호세기가 큰 그룹부터 차례로 간섭제거를 수행하는 방법이다. 본 발명은 더욱 정확한 그룹화를 위하여 각 핑거(finger)별 수신신호 전력 추정치뿐만 아니라 최대 비 결합기(Maximal Ratio Combiner)의 출력값인 연성비트 판정값을 동시에 이용하여 신호의 순위를 결정하고, 핑거 선택기에 의해 선택된 핑거들을 그룹화하여 간섭제거를 수행한다. 이때, 최대 비 결합기의 출력값인 연성비트 판정값은 채널과 독립적이며 송신시의 비트 정보를 가지고 있기 때문에, 수신신호의 전력 추정치와 함께 이용하면 보다 정확한 그룹화가 이루어질 수 있다.
Abstract:
1. 청구범위에 기재된 발명이 속하는 기술분야 본 발명은 제약조건을 갖는 평균평방 오차 최소화 방법을 이용한 적응형 수신 장치에 과한 것임. 2. 발명이 해결하고자하는 과제 본 발명은 적응 필터의 출력 신호를 이용하여 MMSE를 최소화하는데 이용되는 탭 계수가 정상적으로 적응할 수 있도록 하므로써, 수신 장치의 성능을 현저하게 향상시킬 수 있는 적응형 수신 장치를 제공하는데 그 목적이 있다. 3. 발명의 해결방법의 요지 본 발명은, 수신신호를 필터링하는 적응 필터링수단; 필터링된 신호를 이용해 채널의 위상과 진폭을 예측하는 채널 추정수단; 전송된 신호를 복원하는 신호 복원수단; 갱신 신호와 신호 복원수단의 출력신호를 선택하는 선택수단; 기준신호를 발생하는 기준신호 발생수단; 기준신호를 이용해 필터링된 신호의 오차를 계산하는 오차 계산수단; 및 오차에 따라 탭 계수를 변화시키는 탭 계수 조절수단을 포함한다. 4. 발명의 중요한 용도 본 발명은 CDMA 시스템에서의 적응형 수신 장치에 이용됨.
Abstract:
Disclosed is a non-linear adaption narrow band interference noise removing circuit in binary data communication system including a non-linear function unit(theta(.)) which discriminates and removes a binary signal of non-gaussian components about a signal(e(n)) including a binary signal(m(n)) and a estimate error signal(x"(n!n-1!)) among sampling signals input from outside and is formed as feedback loop, and a non-linear function unit(Ar'(z)) which estimates a current narrow band interference noise by using sampling signals regenerated by decreasing the effect of the non-gaussian components of the binary signal. Thus, the narrow band interference noise in a binary data communication system can be removed.
Abstract:
PURPOSE: A multimedia service providing device and a method thereof are provided to offer a multimedia service by guaranteeing scalability and by reducing a performance. CONSTITUTION: A multi-expression encoding unit(100) executes MDC(Multiple Description Coding) for one or more sources. The multi-expression encoding unit outputs a description sequence for the one or more sources. An UEP(Unequal Error Protection) grouping unit(120) outputs an UEP expression sequence comprising the expression sequence according to an UEP degree receiving importance for each source. A transmission code block processing unit(130) generates a transmission block by modulating an UEP expression sequence. [Reference numerals] (100) Multi-expression encoding unit; (110) Systematic raptor coding unit; (120) UEP grouping unit; (130) Transmission code block processing unit; (140) Antenna mapping unit; (150) Pilot insertion unit; (AA) Source; (BB) Expression sequence; (CC,DD,EE) UEP expression sequence; (FF) Transmission block; (GG) Stream; (HH) Antenna
Abstract:
무선통신시스템의 셀 탐색에서 주파수 오프셋에 강한 심볼 동기 획득 장치가 개시된다. 무선통신시스템의 셀 탐색에서 주파수 오프셋에 강한 심볼 동기 획득 장치는 심볼 동기 획득용 베이스 시퀀스를 생성하는 시퀀스 생성부; 상기 베이스 시퀀스를 기초로 변형 시퀀스를 생성하고, 상기 변형 시퀀스와 상기 베이스 시퀀스를 조합하여 동기 패턴을 생성하는 동기 패턴 생성부; 상기 동기 패턴을 기초로 송신 정보를 시간 및 주파수 영역에 매핑하여 송신 프레임을 생성하는 주파수 매핑부; 및 상기 송신 프레임을 송신하는 송신부를 포함한다. 동기채널, 심볼 동기, 주파수 오프셋, 시퀀스, 상관.
Abstract:
PURPOSE: An apparatus for obtaining symbol timing synchronization which is strong for a frequency offset in a cell search of a wireless communication system is provided to create a synchronization pattern for obtaining symbol acquisition and allocate the synchronization pattern to a synchronization channel. CONSTITUTION: A sequence generator generates base sequence for symbol synchronization acquisition(S1001). A pattern generator creates transformation sequence based on the base sequence(S1002). The pattern generator creates synchronization pattern by combining the base sequence and the transformation sequence(S1003). A frequency mapping unit creates transmission frame based on the synchronization pattern(S1004). A transmitting unit transmits the created transmitting frame.