Abstract: There is provided a method of selecting a satellite for positioning in a global navigation satellite system, which includes: receiving satellite signals from satellites that a receiver can receive; calculating DOP where pseudorange weight is applied for each of satellite signal combinations including at least four or more of the satellite signals by the receiver; and selecting a satellite signal combination having the smaller DOP than a standard in the satellite signal combinations by the receiver.

Abstract: The method includes converting, by the receiver, an input signal into a return-to-zero (RZ) signal, generating, by the receiver, a first summation signal by performing an exclusive-or (XOR) operation on the RZ signal and a delayed signal obtained by delaying the RZ signal by a reference time, collecting, by the receiver, n-length seed codes from the first summation signal, generating, by the receiver, a PN code based on the seed codes, and generating, by the receiver, a second summation signal by performing an XOR operation on the PN code and the delayed signal.

Abstract: The method includes converting, by the receiver, an input signal into a return-to-zero (RZ) signal, generating, by the receiver, a first summation signal by performing an exclusive-or (XOR) operation on the RZ signal and a delayed signal obtained by delaying the RZ signal by a reference time, collecting, by the receiver, n-length seed codes from the first summation signal, generating, by the receiver, a PN code based on the seed codes, and generating, by the receiver, a second summation signal by performing an XOR operation on the PN code and the delayed signal.

Abstract: 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.

Abstract: 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 BOCsin(6,1), combining partial correlation functions constituting an autocorrelation function of CBOC(6,1,1/11) to generate a correlation function, and weighted-combining the correlation function to generate an unambiguous correlation function.

Abstract: There is provided a method of creating an AltBOC correlation function that includes: receiving an AltBOC signal by a receiver; analyzing a subcarrier of the AltBOC signal into eight partial subcarriers having the same period by the receiver; creating partial correlation functions by correlating each of the eight partial subcarriers with the AltBOC signal by the receiver; and creating a resultant correlation function by combining the partial correlation functions by the receiver.

Abstract: 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.

Abstract: There is provided a method of creating an AltBOC correlation function that includes: receiving an AltBOC signal by a receiver; analyzing a subcarrier of the AltBOC signal into eight partial subcarriers having the same period by the receiver; creating partial correlation functions by correlating each of the eight partial subcarriers with the AltBOC signal by the receiver; and creating a resultant correlation function by combining the partial correlation functions by the receiver.

Abstract: There is provided a method of selecting a satellite for positioning in a global navigation satellite system, which includes: receiving satellite signals from satellites that a receiver can receive; calculating DOP where pseudorange weight is applied for each of satellite signal combinations including at least four or more of the satellite signals by the receiver; and selecting a satellite signal combination having the smaller DOP than a standard in the satellite signal combinations by the receiver.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 BOCsin(6,1), combining partial correlation functions constituting an autocorrelation function of CBOC(6,1,1/11) to generate a correlation function, and weighted-combining the correlation function to generate an unambiguous correlation function.