Industrial Technology Research Institute

Wei Ping Chuang

Pang-An Ting

Jiun-Yo Lai

Huei-Jin Lin

Yung-Yih Jian

Jiann-An Tsai

Chun-Chun Kuo

An apparatus and method for cell acquisition and downlink synchronization acquisition in an OFDMA wireless communication system are provided. In an SS apparatus in a broadband wireless communication system, a preamble subcarrier acquirer extracts subcarrier values having a preamble code from an FFT signal. A multiplier code-demodulates the subcarrier values by multiplying the subcarrier values by a preamble code. A correlator calculates a plurality of differential correlations in the code-demodulated signal. An IFFT processor IFFT-processes the differential correlations by mapping the differential correlations to subcarriers. A maximum value detector detects a maximum value from the IFFT signal and calculates a timing offset using an IFFT output index having the maximum value.

FFT-size detection and cell search for a cellular communication system

The invention provides an FFT-size detection method and system and a cell search method and system based on FFT-size detection, and more particularly to a cell search method based on FFT-size detection in cellular system. The cell search method utilizes two frames to correctly detect the actual cell ID. The cell search method uses the first frame to detect the actual FFT size of a received signal. When the FFT size is determined, the cell search method use the second frame to detect the cell ID of a base station outputting the received signal based on the FFT size.

FFT-size detector and FFT-size detection method and cell search apparatus and cell search method in cellular system

The method disclosed in the invention comprises setting a plurality of subcarrier position hypotheses for a received preamble according to a plurality of ideal subcarrier positions and the maximum amount of integer carrier frequency offset (ICFO), generating a plurality of preamble pattern hypotheses by retrieving the received preamble according to the subcarrier position hypotheses, calculating the correlation between the preamble pattern hypotheses and a plurality of specified preamble patterns, determining to which sector the received preamble belongs according to a correct preamble pattern, the specified preamble pattern having the highest correlation with the preamble pattern hypotheses, obtaining a correct subcarrier position according to the sector to which the received preamble belongs; and estimating the ICFO by calculating the offset between the correct subcarrier position and the subcarrier position hypothesis of the preamble pattern hypothesis having the highest correlation with the correct preamble pattern.

Method and device for estimating integer carrier frequency offset

A hybrid beamforming apparatus and method are proposed for a communication system. The hybrid beamforming apparatus includes a plurality of antennas, a plurality of FFT, a plurality of hybrid weight-coefficient generators and a plurality of adders. In each of the hybrid weight-coefficient generators, the weight coefficient for each subcarrier is calculated by a time-domain correlation matrix and a cross-correlation vector, which is calculated by a frequency domain signal and a training signal. The hybrid beamforming apparatus and method according to the present invention can enhance immunity for multipath effect with lower system complexity.

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Kaohsiung, Taiwan

Wei Ping Chuang