Abstract:
PURPOSE: A method for tracking the carrier wave frequency error and the sampling frequency error of an orthogonal frequency divisional multiplexing(OFDM) wireless communication system and an apparatus for the same are provided to improve the performance of the system as well as to improve the reliability of estimation value. CONSTITUTION: An apparatus for tracking the carrier wave frequency error and the sampling frequency error of an orthogonal frequency divisional multiplexing(OFDM) wireless communication system includes an analog/digital converter(121), a guard interval cancel block(122), a fast Fourier converter(123), a frequency region equalizer(124), and an error tracking/compensating block(126). The analog/digital converter(121) converts the signal received from the reception block into a digital signal. The guard interval cancel block(122) removes the guard interval from the converted digital signal. The fast Fourier converter(123) converts the signal cancelled the guard interval into a signal of the frequency region. The frequency region equalizer(124) recovers the signals distorted by the communication channel. And, the error tracking/compensating block(126) tracks and compensates the phase error due to the carrier wave frequency error and the sampling frequency error by using the signal received from the frequency region equalizer(124).
Abstract:
FM 신호와디지털변조신호를결합한 FAM 전송장치및 방법이개시된다. FAM 전송방법은모노또는스테레오방송을위한오디오정보를담고있는오디오신호를주파수변조(Frequency Modulation, FM) 방식에따라변조하여생성된 FM 신호를입력받는단계; 상기모노또는스테레오방송에대한부가서비스를제공하기위해필요한디지털데이터를진폭변조(Amplitude Modulation, AM) 계열의디지털변조방식에따라변조하여생성된디지털변조신호를입력받는단계; 및상기 FM 신호와상기디지털변조신호를결합하는단계를포함할수 있다. FAM 수신방법은 FM 신호에디지털변조된 AM 신호가결합하여생성된 FAM 신호를수신하는단계; 신호의진폭을일정하게제한하는리미터(Limiter)를이용하여상기수신된 FAM 신호로부터 FM 신호를추출하는단계; 및상기추출된 FM 신호를 FM 복조방식에따라복조하여모노또는스테레오방송을위한오디오정보를담고있는오디오신호를출력하는단계를포함할수 있다. FAM 수신방법은 FM 신호에디지털변조된 AM 신호가결합하여생성된 FAM 신호를수신하는단계; 상기수신된 FAM 신호에비동기검파(Noncoherent Detection) 방식을적용하여디지털변조된 AM 신호를추출하는단계; 및상기추출된디지털변조된 AM 신호를디지털복조방식에따라복조하여디지털데이터를출력하는단계를포함할수 있다.