Abstract:
Provided are a method of scheduling spectrum sensing and a method of allocation uplink radio resource in a cognitive radio communication system. The method of scheduling spectrum sensing in a cognitive radio communication system includes classifying terminals in a cell into terminals affecting spectrum sensing and terminals not affecting spectrum sensing, and performing spectrum sensing when it is determined that uplink signals of other terminals do not affect spectrum sensing based on results of the classification.
Abstract:
Disclosed herein are a method and a system for performing initial ranging in a cognitive radio network The method for performing initial ranging in a cognitive radio network includes: detecting signals received in one or more ranging sections; estimating a tint time offset based on a correlation between subcarrier indices of the signals detected in the one or more ranging sections; estimating a second time offset based on correlations for the signals detected in the one or more ranging sections and a plurality of codes that are predetermined and detecting an initial ranging code among the plurality of codes; and estimating a time offset of a CPE performing initial ranging with the detected initial ranging code using the first time offset and the second time offset that are estimated.
Abstract:
Disclosed herein are an apparatus and method for measuring a broadband Passive Intermodulation Distortion (PIMD) signal. The apparatus for measuring a broadband PIMD signal includes a Radio Frequency (RF) processing unit for combining one or more transmission signals into a single output signal and transmitting the output signal to a feeder so as to measure a PIMD signal and for generating a beat frequency signal using the PIMD signal received from the feeder, and a digital processing unit for transferring a control signal required so as to control the RF processing unit, receiving the beat frequency signal, and then measuring a location of a passive element in the feeder in which the PIMD signal has been generated by performing digital signal processing on the beat frequency signal.
Abstract:
Disclosed herein are an apparatus and a method of estimating a channel in consideration of a residual synchronization offset. The apparatus of estimating a channel in consideration of a residual synchronization offset includes: a channel estimating unit estimating the channel using pilots scattered over a plurality of OFDM symbols and calculating a first channel estimated value as the estimation result, in the case in which an OFDM symbol estimating the channel and an OFDM symbol compensating for the channel are different from each other; and a phase reflecting unit calculating a phase generated by the residual synchronization offset in proportion to a difference between a channel estimation time and a channel compensation time, reflecting the calculated phase in the first channel estimated value, and calculating a second channel estimated value as the reflection result.
Abstract:
Provided is a method of generating a pilot pattern capable of perform adaptive channel estimation, and a method and apparatus of a base station and a method and apparatus of a terminal using the pilot pattern.The pilot pattern selects pilot symbol positions based on distances from pilots of previous orthogonal frequency division multiple access (OFDMA) symbols to a subcarrier position of a current OFDMA symbol in the frequency domain and the time domain, so that a low pilot density is maintained so as to effectively transmit data, and stable channel estimation performance can be obtained even in a bad channel environment.In addition, the minimum burst allocation size is determined according to the channel environment between the base station and the terminal, guaranteeing channel estimation performance suitable for the channel environment, and improving granularity, channel estimation latency, and channel estimation memory size.