Patent application number | Description | Published |
20090323837 | METHOD FOR ESTIMATING FREQUENCY OFFSET IN SYSTEM UTILIZING A PLURALITY OF SUB-CARRIERS - An integer frequency offset estimation scheme in an orthogonal frequency division multiplexing (OFDM)-based system is disclosed. A receiving apparatus for receiving a signal according to an OFDM includes an OFDM symbol acquisition module for acquiring at least two consecutive OFDM symbols, a symbol operation module for operating upon pilot symbols and/or data symbols belonging to frequency bands determined according to a plurality of candidates for integer frequency offsets among a plurality of pilot symbols and a plurality of data symbols included in the acquired OFDM symbols, and an integer frequency offset estimation module for selecting a final integer frequency offset among a plurality of candidates for integer frequency offsets according to magnitudes of operation values obtained by the symbol operation module, wherein the frequency bands determined according to the candidate for integer frequency offsets are obtained by frequency-shifting preset frequency bands at which all pilot symbols are transmitted according to the candidate for integer frequency offsets. | 12-31-2009 |
20130223576 | FREQUENCY OFFSET ESTIMATION APPARATUS AND METHOD OF OFDM SYSTEM - The present invention provides an apparatus and method for estimating a frequency offset which are robust against non-Gaussian noise. In a frequency offset estimation method of an Orthogonal Frequency Division Multiplexing (OFDM) system using a training symbol, the method includes receiving a reception signal, setting a specific initial frequency offset corresponding to the reception signal, and calculating a log-likelihood function based on a Complex Isotropic Symmetric α Stable (CISαS) probability density function obtained by modeling non-Gaussian noise included in the reception signal and estimating an optimum frequency offset based on the log-likelihood function and the initial frequency offset through a Maximum Likelihood Estimator (MLE). Accordingly, in a non-Gaussian noise environment, frequency offset estimated performance can be improved as compared with a conventional method in which noise is assumed to be a normal distribution. | 08-29-2013 |
20140125522 | METHOD OF GENERATING CORRELATION FUNCTION WITH NO SIDE-PEAK AND SYSTEM FOR TRACKING BINARY OFFSET CARRIER SIGNAL - Disclosed herein are a method of generating a correlation function with no side-peak and a system for tracking a BOC signal in order to synchronize the BOC signal. The method of generating a correlation function includes step S | 05-08-2014 |
20140351306 | METHOD OF GENERATING CORRELATION FUNCTION, METHOD OF TRACKING SIGNAL AND SIGNAL TRACKING SYSTEM - A method of generating a correlation function, a method of tracking a signal, and a signal tracking apparatus are provided. The method of generating a correlation function involves receiving a CBOC(6,1,1/11) signal, interpreting a subcarrier pulse period of the CBOC(6,1,1/11) signal as a subcarrier pulse period of BOC | 11-27-2014 |
20150029961 | METHOD OF SELECTING TRANSMISSION PARAMETER AND DYNAMIC SPECTRUM ALLOCATION APPARATUS - A method of selecting a transmission parameter and a spectrum allocation apparatus are provided. The method of selecting a transmission parameter involves collecting frequency band information comprising a frequency bandwidth and communication environment information comprising a power density of noise, constituting a plurality of single-objective fitness functions comprising a bandwidth fitness function based on data transmission using two frequency bands, using the frequency band information and the communication environment information, constituting a multi-objective fitness function obtained by assigning a weight value to each of the plurality of single-objective fitness functions, and selecting the transmission parameter by applying a genetic algorithm to the multi-objective fitness function. | 01-29-2015 |
20150030108 | FREQUENCY OFFSET ESTIMATION METHOD IN OFDM SYSTEM AND OFDM RECEIVER USING THE SAME - A method of estimating a frequency offset based on a training symbol in a receiver of an orthogonal frequency division multiplexing (OFDM) system, includes receiving a first training symbol having a periodicity and a predetermined second training symbol, and calculating a correlation value for the first training symbol based on a coherence phase bandwidth (CPB). The method further includes determining a position of a peak value from the correlation value for an integer multiple frequency offset candidate based on a threshold value, and calculating a correlation value for the second training symbol based on the CPB. The method further includes estimating a position corresponding to a maximum value of the correlation value for the second training symbol as the frequency offset based on the position of the peak value. | 01-29-2015 |
20150031309 | METHOD OF SPECTRUM SENSING AND APPARATUS USING THE SAME - A method of spectrum sensing and an apparatus for spectrum sensing are provided. A method of spectrum sensing involves partitioning, by a processor, a spectrum sensing section into a plurality of sub-periods each having a same size, performing energy detection in each of the plurality of sub-periods, and determining whether a primary user's signal is present in the spectrum sensing section based on presence of a primary user's signal in each of the plurality of sub-periods and a test statistic in each of the plurality of sub-periods. | 01-29-2015 |