Abstract: A method for receiving radio packets through short-range wireless communication includes receiving a first radio signal through the short-range wireless communication, identifying a preamble used for synchronization of the short-range wireless communication from a analog signal of the received first radio signal, determining whether the frequency from the identified preamble is within a specified frequency offset range, and processing data from the received first radio signal if the frequency from the identified preamble is within the specified frequency offset range.

Abstract: A method includes receiving information collected by one or more auxiliary communication terminals by radio signals in order for discovering the radio access technology accessible by the mobile communication terminal, and determining connection with one of one or more radio access technologies on the basis of the information collected by the radio signals. The collected information includes information created on the basis of strength of radio signals, which are received by the auxiliary communication terminals from wireless access devices. Determining connection includes determining a wireless access device to be connected on the basis of signal strength information of the radio signals from the auxiliary communication terminals, the signal strength information being measured by the mobile communication terminal, and information derived from the strength of the radio signals included in the collected information.

Abstract: A short-range wireless communication access device controls a first network interface to send broadcast radio data packets for allowing a portable terminal to discover the short-range wireless communication access device in a specified first time range, on the basis of time synchronized with the portable terminal to access a short-range wireless communication network. Further, the short-range wireless communication access device receives operation scenario information for controlling whether to send the broadcast radio data packets through a second network interface, and controls the first network interface to cyclically send the broadcast radio data packets in accordance with a repetition cycle in the first time range based on the repetition cycle included in the operation scenario information, the specified first time range in the repetition cycle, and the time determined from the radio signal received through the second network interface.

Abstract: A short-range wireless communication access device controls a first network interface to send broadcast radio data packets for allowing a portable terminal to discover the short-range wireless communication access device in a specified first time range, on the basis of time synchronized with the portable terminal to access a short-range wireless communication network. Further, the short-range wireless communication access device receives operation scenario information for controlling whether to send the broadcast radio data packets through a second network interface, and controls the first network interface to cyclically send the broadcast radio data packets in accordance with a repetition cycle in the first time range based on the repetition cycle included in the operation scenario information, the specified first time range in the repetition cycle, and the time determined from the radio signal received through the second network interface.

Abstract: A method includes receiving information collected by one or more auxiliary communication terminals by radio signals in order for discovering the radio access technology accessible by the mobile communication terminal, and determining connection with one of one or more radio access technologies on the basis of the information collected by the radio signals. The collected information includes information created on the basis of strength of radio signals, which are received by the auxiliary communication terminals from wireless access devices. Determining connection includes determining a wireless access device to be connected on the basis of signal strength information of the radio signals from the auxiliary communication terminals, the signal strength information being measured by the mobile communication terminal, and information derived from the strength of the radio signals included in the collected information.

Abstract: A method for receiving radio packets through short-range wireless communication includes receiving a first radio signal through the short-range wireless communication, identifying a preamble used for synchronization of the short-range wireless communication from a analog signal of the received first radio signal, determining whether the frequency from the identified preamble is within a specified frequency offset range, and processing data from the received first radio signal if the frequency from the identified preamble is within the specified frequency offset range.

Abstract: A relay method of a wireless communication system according to one embodiment of the present invention relates to a relay method of a wireless communication system in which at least one relay device communicates with a base station. The relay method comprises the steps of: each relay device setting information about a frequency band to be relayed, composing a control signal including the information about the set frequency band, and transmitting the control signal to at least one relay device; and receiving the control signal, extracting the information about the frequency band included in the control signal, amplifying the signal according to the information about the frequency band set in each relay device, and transmitting the amplified signal to at least one terminal.

Abstract: Provided is an interleaving method that can reduce error occurring during transmission at a receiving end in an Orthogonal Frequency Division Multiplexing (OFDM) system. According to the interleaving method, transmitted data bits are recorded in an interleaving memory; and the stored data bits are read based on a predetermined sequence to perform symbol interleaving, tone interleaving and cyclic shift simultaneously. Also, to simplify the logic of the OFDM system, the data bits transmitted from an interleaver go through Fast Fourier Transform (FFT) mapping, and the FFT mapped data bits are modulated. In short, the logic can be simplified by performing FFT mapping followed by modulation.

Abstract: An FFT apparatus for quickly processing input signals and method thereof is disclosed. In performing the FFT for processing N input signals, four N/4-point FFT units implemented by radix-2 single-path delay feedback (R2SDF) units performs the FFT with respect to the input signals, and a radix-4 computation unit performs a radix-4 computation with respect to the signals transferred from the N/4-point FFT units. Accordingly, the input signals are processed in parallel through the N/4-point FFT units, and thus a quick process of the input signals can be performed.

Abstract: Disclosed are a method and apparatus for detecting minute oscillation in a WiBro repeater, and the WiBro repeater having the same. The method of detecting minute oscillation in a WiBro repeater includes: calculating an autocorrelation value of an input signal inputted to the repeater; calculating energy of the input signal; calculating the amount of oscillation by dividing the autocorrelation value by the energy; and comparing the amount of oscillation with a predetermined threshold value to determine whether or not the minute oscillation occurs in the repeater.

Abstract: A repeater including a downlink signal processor, which receives a downlink frame from a radio access station (RAS) and transmits the downlink frame to a portable Internet terminal, and an uplink signal processor, which receives an uplink frame from the portable Internet-terminal and transmits the uplink frame to the RAS, is provided, including: an ID storage unit to store identification (ID) information of the repeater; switches to switch a signal transmission path so that the downlink frame can be transmitted to the portable Internet terminal through the downlink signal processor, or the uplink frame can be transmitted to the RAS through the uplink signal processor; and a switch control unit to control the switches such that the ID information of the repeater is inserted into part of the downlink frame and the downlink and uplink frames are transmitted.

Abstract: Disclosed are a method and apparatus for detecting minute oscillation in a WiBro repeater, and the WiBro repeater having the same. The method of detecting minute oscillation in a WiBro repeater includes: calculating an autocorrelation value of an input signal inputted to the repeater; calculating energy of the input signal; calculating the amount of oscillation by dividing the autocorrelation value by the energy; and comparing the amount of oscillation with a predetermined threshold value to determine whether or not the minute oscillation occurs in the repeater.

Abstract: Disclosed is a method and apparatus for positioning a portable subscriber station (PSS) using a WiBro repeater, and a repeater having the apparatus. The method of positioning the portable subscriber station in a network having a radio access station (RAS) and a repeater, including the operations of: detecting a preamble signal transmitted from the RAS; generating a reference time by measuring a receiving time of the preamble signal and by compensating the receiving time of the preamble signal by taking into consideration a signal delay time between the RAS and the repeater; measuring a receiving time of a ranging signal received from the PSS on the basis of the reference time; and calculating the receiving time of the ranging signal by using a time stamp generated on the basis of the receiving time of the preamble signal.

Abstract: Disclosed is a method of measuring the throughput of uplink data in a WiBro repeater, the method including the operations of: (a) extracting a plurality of tiles from a predetermined number of symbols that are collected over a plurality of times by performing frequency conversion on the uplink data; (b) calculating power values for the respective extracted tiles; (c) calculating an average noise value from the calculated power values; (d) calculating a threshold value, which is used to identify noise, from the average noise value, and calculating the number of tiles having power values more than the threshold value; and (e) calculating the throughput by estimating based on the number of the tiles the number of subchannels carrying data.

Abstract: There is provided a channel estimation apparatus for estimating a radio channel environment by multiplying a currently received bit signal of a pilot signal and previously received bit signals by weights, and summing the weighted currently received bit signal and the weighted previously received bit signals in a CDMA mobile communication system receiving the pilot signal comprised of a stream of bits having given bit values, and a power control signal comprised of power control bits. In the channel estimation, a predictor predicts a next bit signal succeeding the currently received bit signal, multiplies the predicted next bit signal by a weight, and generates a weighted next bit signal. A summer sums the weighted next bit signal from the predictor, the weighted currently received bit signal and the previously received bit signals.

Abstract: Provided is an interleaving method that can reduce error occurring during transmission at a receiving end in an Orthogonal Frequency Division Multiplexing (OFDM) system. According to the interleaving method, transmitted data bits are recorded in an interleaving memory; and the stored data bits are read based on a predetermined sequence to perform symbol interleaving, tone interleaving and cyclic shift simultaneously. Also, to simplify the logic of the OFDM system, the data bits transmitted from an interleaver go through Fast Fourier Transform (FFT) mapping, and the FFT mapped data bits are modulated. In short, the logic can be simplified by performing FFT mapping followed by modulation.

Abstract: An FFT apparatus for quickly processing input signals and method thereof is disclosed. In performing the FFT for processing N input signals, four N/4-point FFT units implemented by radix-2 single-path delay feedback (R2SDF) units performs the FFT with respect to the input signals, and a radix-4 computation unit performs a radix-4 computation with respect to the signals transferred from the N/4-point FFT units. Accordingly, the input signals are processed in parallel through the N/4-point FFT units, and thus a quick process of the input signals can be performed.

Abstract: A multi-band orthogonal frequency division multiplexing (OFDM) system transmits the same symbol at least two times, and a receiving end can receive transmission data from a transmitting end accurately even when an error occurs from a wireless resource used by the multi-band OFDM system. To this end, the multi-band OFDM system has a transmitting end which selects one among at least three symbols being repetitively transmitted at least two times, and transmits the selected symbol by using different wireless resources so that the selected symbol is not consecutively transmitted, and a receiving end which receives the symbols from the transmitting end.

Abstract: Disclosed is a matched filter and a method for performing cross correlation thereof. The matched filter includes a demultiplexer for demultiplexing an input sample signal into a predetermined number of signals; and cross correlators that perform a cross correlation of each of the demultiplexed sample signals with a predetermined sequence. Therefore, when the matched filter of the present invention is applied to a UWB system having a high sampling rate, the cross correlation operation can be performed at a high rate simply by using low-rate multipliers.

Abstract: A method for seamlessly receiving a symbol from a transmitting end at a receiving end even when error occurs in a certain radio resource of a multiband OFDM system that transmits a same symbol at least two times. The multiband OFDM system includes a transmitting end selecting two radio resources from at least three radio resources and consecutively transmitting a symbol using the selected radio resources, and a receiving end receiving the symbol from the transmitting end.