Abstract: Disclosed is a method for modulating and demodulating data. The method composes symbols by grouping a plurality of symbols for pulse position modulation to newly add symbol compositions to fixed symbols used for the pulse position modulation of the related art. Further, the method uses grouped symbols to improve data transmission rate as the average amount of information increases.

Abstract: A signaling method between a cognitive radio (CR) base station and a CR terminal in a CR environment, and a channel division method used for the signaling method, includes: detecting a channel usage of an incumbent system, which communicates with a CR base station; sensing an outband channel to communicate with the CR base station; receiving an EOS, which is broadcasted from the CR base station via the outband channel according to a predetermined period; and transmitting a sensing report signal with respect to the channel to the CR base station.

Abstract: Disclosed is a method for modulating and demodulating data. The method composes symbols by grouping a plurality of symbols for pulse position modulation to newly add symbol compositions to fixed symbols used for the pulse position modulation of the related art. Further, the method uses grouped symbols to improve data transmission rate as the average amount of information increases.

Abstract: The rate compatible code is formed by forming an m dimensional product code by using a systematic block code in a predetermined number of axes: The m dimensional product code is divided into an information block and 2m?1 parity blocks. Indices are allocated to the divided blocks of the information block and 2m?1 parity blocks. Combinations of the information block and corresponding parity blocks adjacent to the information block are obtained. A first weighting factor w1 for the combinations is estimated and saved. Another parity block adjacent to the saved combination is found and a new combination is formed. The first weighting factor w1 for the new combination is estimated. If there are combinations having the same first weighting factor w1, a second weighting factor w2 for the combinations is estimated and the combinations having a smaller value of w2 are neglected. Rate compatible having the combinations are formed.

Abstract: A signaling method between a cognitive radio (CR) base station and a CR terminal in a CR environment, and a channel division method used for the signaling method, includes: detecting a channel usage of an incumbent system, which communicates with a CR base station; sensing an outband channel to communicate with the CR base station; receiving an EOS, which is broadcasted from the CR base station via the outband channel according to a predetermined period; and transmitting a sensing report signal with respect to the channel to the CR base station.

Abstract: A fast LUT predistortion apparatus and method for compensating nonlinear distortion of the high power amplifier HPA is disclosed. The apparatus includes a predistortion unit for predistorting an input complex digital signal based on a look up table LUT implementation and outputting a predistorted complex signal; and a power amplifier for amplifying the predistorted signal and outputting an amplified complex signal.

Abstract: Provided is an adaptive filter that can reduce the computational complexity. The adaptive filter includes: a segmentation unit for segmenting N number of input signals into G number of signal groups; sub-filter unit having G number of sub-filters, which are corresponding to each of the signal groups, for filtering the corresponding signal group; an addition unit for summating the output signals of the sub-filter unit; an error computing unit for generating an error signal by comparing the output signals of the addition unit with a desired signal; filter coefficient updating unit having G number of filter coefficient updating units, each of which is corresponding to each of the sub-filters, for updating the filter coefficient of the corresponding sub-filter; and a switching unit for inputting the error signal to any one of the filter coefficient updaters optionally with respect to an iteration number k.

Abstract: Provided is a method for forming a rate compatible code using high dimensional product codes and a computer-readable recording medium for recording a program that implements the program. The rate compatible code, which can provide various encoding rates, is formed by discriminating parity blocks and determining a punctured pattern for each parity block, m being more than two.

Abstract: A fast LUT predistortion apparatus and method for compensating nonlinear distortion of the high power amplifier HPA is disclosed. The apparatus includes a predistortion unit for predistorting an input complex digital signal based on a look up table LUT implementation and outputting a predistorted complex signal; and a power amplifier for amplifying the predistorted signal and outputting an amplified complex signal.

Abstract: Provided is an adaptive filter that can reduce the computational complexity. The adaptive filter includes: a segmentation unit for segmenting N number of input signals into G number of signal groups; sub-filter unit having G number of sub-filters, which are corresponding to each of the signal groups, for filtering the corresponding signal group; an addition unit for summating the output signals of the sub-filter unit; an error computing unit for generating an error signal by comparing the output signals of the addition unit with a desired signal; filter coefficient updating unit having G number of filter coefficient updating units, each of which is corresponding to each of the sub-filters, for updating the filter coefficient of the corresponding sub-filter; and a switching unit for inputting the error signal to any one of the filter coefficient updaters optionally with respect to an iteration number k.