Patent ID: 7936844
Filing Date: 2011-05-03
Classification: H04L

Abstract:
1. A channel estimation apparatus with an optimal search, suitable for a demodulator, said demodulator comprises a fast fourier transform unit (FFT unit), a shift unit, a correction unit and a signal processing module, wherein the FFT unit generates a frequency domain received signal, the demodulator selects one of the frequency domain received signal, an output signal of the shift unit and an output signal of the correction unit as a feedback signal, and the channel estimation apparatus is used for estimating an entire channel frequency response and an optimal shift information from the frequency domain received signal according to the feedback signal, wherein the frequency domain received signal comprises a plurality of symbols and each of the symbols comprises a scattered pilot data and a transmission parameter; said channel estimation apparatus comprising: a time domain axis channel estimation unit, for receiving the frequency domain received signal and performing the channel estimation in the time domain dimension so as to estimate an initial channel frequency response according to a channel information formed by the plurality of scattered pilot data; a peak detection module, for detecting a peak position of the initial channel frequency response in the time domain and outputting the peak position to be used as a peak information; a first shift unit, for adjusting a relative position of the initial channel frequency response in the time domain according to the optimal shift information so as to generate an adjusted initial channel frequency response; a frequency domain axis channel estimation unit, for performing the channel estimation in the frequency domain dimension according to a numerical value of the adjusted initial channel frequency response so as to obtain the entire channel frequency response; and an optimal shift searching module, for generating a plurality of shift information according to the peak information and deciding the optimal shift information from the plurality of shift information by using the feedback signal and the entire channel frequency response.