Abstract:
An AGC(Automatic Gain Control) apparatus and method for performing in a preamble and header data period are provided to prevent degradation of performance by performing secondary precise automatic gain controlling in a header data section. A primary AGC unit(220) extracts reception packet from digital-converted data in a VGA(Variable Gain-controlled Amplifier)(210) and extracts a symbol timing to calculate a primary AGC value in a preamble section. A secondary AGC unit(230) extracts the reception packet and the symbol timing from the digital-converted data to calculate a secondary control value in a header section. A switch(232) selects to digital-gain-control or an analog-gain-control an output of the secondary AGC unit. A gain controller(226) calculates gain control data according the output of a comparator(225), and a symbol timing detector(223) detects a symbol timing of a packet detected by a packet detector(222). A power calculating unit(224) calculates the average power of a preamble according to the output of the symbol timing detector, and a digital-analog converter(227) adjusts the gain of the VGA by converting the control data of gain controller in analog.
Abstract:
An initial coefficient acquisition device of a decision feedback equalizer using the FFT(Fast Fourier Transform) and a method thereof are provided to estimate a non-causal channel impulse response characteristic in a non-data section by using a limited preamble, and not to perform matrix operation by using the FFT. A channel impulse response estimator(41) delays a receiving signal of a time domain to convert the signal into a signal of a frequency domain, and estimates a non-causal channel impulse response. A filter coefficient obtainer extracts the predetermined number of signals from the estimated non-causal channel impulse response signal to convert the extracted signals into signals of the frequency domain, and obtains the initial coefficient value of a feed-forward filter. A feedback filter coefficient obtainer converts the estimated non-causal channel impulse response signal into a signal of the frequency domain, and converts a result, obtained by multiplying the converted signal by the initial coefficient value of the feed-forward filter, into a signal of the time domain, then calculates an initial coefficient value of the feed-forward filter.
Abstract:
본 발명은 자동이득 제어방법 및 이를 수행하는 수신장치에 관한 것이다. 본 발명에서, 수신장치는 수신되는 임펄스 신호를 아날로그 디지털 변환부에서 양자화하여 출력하는 양자화 값의 통계정보에 기초해 이득 조정폭을 결정한다. 그리고, 결정된 이득 조정폭에 기초해 가변이득 증폭부의 증폭이득을 제어한다. 임펄스, 수신장치, VGA, 자동이득제어, 이득
Abstract:
본 발명은 저속 무선 개인 통신 네트워크에서 다중모드 송수신 장치 및 그 방법에 관한 것으로, 기 설정된 제어신호에 따라 다중의 저주파수대 변복조를 선택적으로 수행하여 송수신 신호가 디지털 변복조되도록 하는 다중모드 모뎀부; 상기 제어신호에 따라 상기 다중의 저주파수대 변복조에 제공하는 샘플링 클럭을 생성하고, 소수형 반송파 주파수를 생성하는 주파수합성 및 클럭생성부; 상기 다중모드 모뎀부로부터 발생하는 디지털 변조 신호를 아날로그 신호로 변환한 후, 상기 반송파 주파수를 이용하여 상기 변환된 아날로그 신호를 전송 채널에 대응하는 무선 변조 신호로 상향 변환하며, 상기 반송파 주파수를 이용하여 안테나로부터 수신되는 무선 변조 신호를 아날로그의 중간 주파수 대역으로 하향 변환한 후, 상기 하향 변환된 아날로그의 중간 주파수 대역 신호를 디지털의 중간 주파수 변조 신호로 변환하는 다중모드 송수신부를 포함하여 구성되며, 이에 의하여 서로 다른 변복조 방식이 공용화된 하나의 송수신 장치를 통해 구현되도록 함으로, 장치의 복잡도 및 생산 비용을 최소화하는 효과를 가진다. 저속 무선 개인 통신 네트워크, LR-WPAN, BPSK, OQPSK, ASK, Low-IF
Abstract:
A multi-mode transmission/reception apparatus in an LR-WPAN(Low Rate-Wireless Personal Area Network) and a transmitting/receiving method thereof are provided to configure a network using devices which support different sorts of modulation/demodulation schemes by performing a multi-mode modulation/demodulation. A multi-mode transmission/reception apparatus in an LR-WPAN includes a multi-mode modem unit(100), a frequency mixing and clock generating unit(200), and a multi-mode transmission/reception unit(300). The multi-mode modem unit modulates and demodulates a transmission/reception signal digitally by selectively performing a multi-mode low frequency modulation/demodulation in response to a predetermined control signal. The frequency mixing and clock generating unit generates a sampling frequency provided to the multi-mode low frequency modulation/demodulation in response to the control signal, and generates a carrier frequency. The multi-mode transmission/reception unit converts the digital signal generated from the multi-mode modem unit into an analog signal, and up-converts the converted analog signal into a wireless modulation signal corresponding to the transmission channel based on the carrier frequency. The multi-mode transmission/reception unit down-converts the wireless modulation signal received from an antenna into an intermediate frequency based on the carrier frequency, and converts the down-converted intermediate frequency signal into a digital intermediate frequency modulation signal.
Abstract:
A reference synchronization signal generator of a wireless communication system is provided to enhance modulation and demodulation performances by generating a reliable system clock in a synchronization system. A reference synchronization signal generator of a wireless communication system includes an external synchronization reference signal generator, a reference synchronization signal generator(120), and a system clock frequency mixer(130). The external synchronization reference signal generator receives an external reference signal and detects a signal. The reference synchronization signal generator generates a reference signal by synchronization with the external reference signal. The system clock frequency mixer generates the system clock by synchronization with the reference signal. The reference synchronization signal generator receives the external reference signal and includes a frequency mixer for synchronizing the reference signal with the external reference signal. A switch is activated by a control signal so that the reference synchronization signal is generated by using an independent reference voltage.