Abstract: A switching regulator includes an inductor connected to an output terminal of the switching regulator, a switching circuit configured to supply a current from an input terminal of the switching regulator to the inductor in response to an activated control signal, and an RC circuit including a sense resistor and a sense capacitor and connected to the inductor in parallel, the sense resistor and the sense capacitor being connected to each other in series at a feedback node.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: There is provided relaxation oscillator. The relaxation oscillator includes: a ramp wave generator generating ramp waves by a complementary operation between a first capacitor module charged and discharged according to a first switching signal and a second capacitor module charged and discharged according to a second switching signal; a negative feedback circuit unit generating a compensation voltage for compensating errors with reference voltage by being fedback with the ramp waves; and a switching signal generator generating the first switching signal controlling the charging and discharging of the first capacitor module and the second switching signal controlling the charging and discharging of the second capacitor module from the compensation voltage and the ramp waves. As a result, the present invention can generate ramp waves having a stable frequency while preventing a frequency from being changed due to a delay or an offset of the comparator.

Abstract: 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.

Abstract: 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.

Abstract: A conventional massage belt provides monotonous sense in use and simple massage effect caused from the rotational motion that draws a simple trajectory in only a forward or reverse direction when a particular body portion is massaged with vibration of the same rotational speed generated from a vibrating portion in which eccentric weights are installed at both sides of a motor and which is installed in a belt body tightly wrapped around the body portion to be massaged such as abdomen.