Abstract: A channel estimation apparatus and the method thereof are disclosed. The channel estimation apparatus includes a time-domain-axis channel estimation unit, a peak-detection module, a first-shift unit, a frequency-domain-axis channel estimation unit and an optimal shift searching module. The time-domain-axis channel estimation unit is used for performing the channel estimation in the time domain so as to obtain initial channel frequency responses by estimating. The peak-detection module is used for outputting a peak information. The shift-optimal-searching module decides the optimal shift information according to the peak information, a feedback signal and entire channel frequency responses. The first-shift unit is used for adjusting the positions of the initial channel frequency responses in the time domain according to the optimal shift information.

Abstract: The present invention describes a method and a system for executing preamble detection, symbol timing recovery, and frequency offset estimation that are applied to a PHS system for executing the preamble symbol detection and timing recovery. The system includes a first absolute value circuit, an average circuit, a multiplier, a sample and accumulate circuit coupled to the multiplier, a second absolute value circuit, a first compare circuit, and a second compare circuit, such that the system with the foregoing structure can detect a preamble symbol by less symbols while performing a timing recovery. The invention also describes a frequency offset computation method and its circuit.

Abstract: A bit synchronization method and system for a GPS, which receives a satellite signal sent by a satellite to accordingly produce a synchronous signal. Each data bit of the satellite signal consists of N CA-codes. A data buffer receives and stores the data bits of the satellite signal. A matched filter filters the N CA-codes of each data bit in order to compute correlations of the N CA-codes of each data bit, and accordingly output a correlation set corresponding to the data bit, wherein the correlation set has N correlations. A selector selects one with the greatest value from the N correlations and uses the CA-code corresponding to the one with the greatest value as the synchronization signal.

Abstract: This invention provides a diversity receiver, which has N branches for receiving M versions of an input signal. The diversity receiver comprises N channel state information estimators, a demodulator and a combining and demapping device. After receiving the M versions of the input signal, the demodulator performs demodulation and then generates M demodulated signals. N channel state information estimators, one channel state information estimator equipped for each branch, respectively fetches the signals from the demodulator to generate M channel parameters related to the M versions of the input signal. The combining and demapping device receives the M demodulated signals, performs signal combining operations and symbol demapping, and finally generate a pre-correcting signal.

Abstract: A transmission parameter recognition apparatus and the method thereof are disclosed. The transmission parameter recognition apparatus includes a correlation function processing module, a correlation symbol summing module and an energy interval detection module. The correlation function processing module computes a correction between two adjoining symbols in a sample sequence to generate a correlation function sequence. The correlation symbol summing module accumulates M symbols in the correlation function sequence to generate an energy interval. Since the distribution of the energy interval is related to the guard interval type, therefore, the energy interval detection module detects the distribution of the energy interval to generate a piece of guard interval information.

Abstract: A transmission parameter recognition apparatus and the method thereof are disclosed. The transmission parameter recognition apparatus includes a correlation function processing module, a correlation symbol summing module and an energy interval detection module. The correlation function processing module computes a correction between two adjoining symbols in a sample sequence to generate a correlation function sequence. The correlation symbol summing module accumulates M symbols in the correlation function sequence to generate an energy interval. Since the distribution of the energy interval is related to the guard interval type, therefore, the energy interval detection module detects the distribution of the energy interval to generate a piece of guard interval information.

Abstract: A channel estimation apparatus with the optimal search and the method thereof are disclosed. The channel estimation apparatus includes a time-domain-axis channel estimation unit, a peak-detection module, a first-shift unit, a frequency-domain-axis channel estimation unit and a shift-optimal-searching module. The time-domain-axis channel estimation unit is used for performing the channel estimation in the time domain so as to obtain initiative channel frequency responses by estimating. The peak-detection module is used for outputting a peak information. The shift-optimal-searching module decides the optimal shift information according to the peak information, a feedback signal and entire channel frequency responses. The first-shift unit is used for adjusting the positions of the initiative channel frequency responses in the time domain according to the optimal shift information.

Abstract: This invention provides a diversity receiver, which has N branches for receiving M versions of an input signal. The diversity receiver comprises N channel state information estimators, a demodulator and a combining and demapping device. After receiving the M versions of the input signal, the demodulator performs demodulation and then generates M demodulated signals. N channel state information estimators, one channel state information estimator equipped for each branch, respectively fetches the signals from the demodulator to generate M channel parameters related to the M versions of the input signal. The combining and demapping device receives the M demodulated signals, performs signal combining operations and symbol demapping, and finally generate a pre-correcting signal.

Abstract: The present invention describes a method and a system for executing preamble detection, symbol timing recovery, and frequency offset estimation that are applied to a PHS system for executing the preamble symbol detection and timing recovery. The system includes a first absolute value circuit, an average circuit, a multiplier, a sample and accumulate circuit coupled to the multiplier, a second absolute value circuit, a first compare circuit, and a second compare circuit, such that the system with the foregoing structure can detect a preamble symbol by less symbols while performing a timing recovery. The invention also describes a frequency offset computation method and its circuit.

Abstract: A bit synchronization method and system for a GPS, which receives a satellite signal sent by a satellite to accordingly produce a synchronous signal. Each data bit of the satellite signal consists of N CA-codes. A data buffer receives and stores the data bits of the satellite signal. A matched filter filters the N CA-codes of each data bit in order to compute correlations of the N CA-codes of each data bit, and accordingly output a correlation set corresponding to the data bit, wherein the correlation set has N correlations. A selector selects one with the greatest value from the N correlations and uses the CA-code corresponding to the one with the greatest value as the synchronization signal.