Electronics and Telecommunications Research Institute

Samsung Electronics Co., Ltd.

Young-Jin Moon

Young-il Kim

Youn-Ok Park

Jun-Woo Kim

Hyun-jae Kim

Young-II Kim

Ki-Seok Kim

Provided are a preamble transmission device of a multi-mode supporting base station and a preamble detecting device of a multi-mode supporting user terminal. Selecting of the preamble signal is driven by the user terminal capable of supporting multi-modes, which contributes to smooth services from a user's viewpoint, and to effective use of the limited radio resources from an operator's viewpoint.

Preamble transmission device of multi-mode supporting base station and preamble detecting device of multi-mode supporting user terminal

The present invention relates to an apparatus and method for variable fast Fourier transform. According to an embodiment of the present invention, two n-point fast Fourier transform (FFT) processors are used to generate two n-point FFT output data or one 2n-point FFT output data. The one 2n-point input data is alternately input to the two n-point FFT processors. Each of the two n-point FFT processors selects a twiddle factor for the n-point input data or the 2n-point input data and performs fast Fourier transform. A butterfly operation is performed on signals obtained by performing fast Fourier transform on the 2n-point input data signal, and the processed signals are aligned in an output order. According to this structure, it is possible to realize a fast Fourier transform hardware engine that selectively performs multi-frequency allocation in a base station system that supports the multi-frequency allocation.

Apparatus and method for variable fast fourier transform

The present invention relates to a fast uplink ranging system and method in a mobile communication system. According to the present invention, a fast uplink ranging system transmits two pairs of ranging codes having the same value at locations spaced by half of FFT pointers. The fast uplink ranging system calculates a correlation value using the received two pairs of ranging codes. An order in which complex exponential twiddle factors for removing complex exponential terms corresponding to a time delay are searched is determined using the correlation value. Therefore, it is possible to reduce a time required for searching a timing error of a terminal using non-periodic symmetry of complex exponential twiddle factors corresponding to the timing error, compared with a known method of searching a complex exponential twiddle factor.

Fast uplink ranging system and method in mobile communication system

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Daejeon, South Korea

Young-Jin Moon