摘要:
Disclosed is an apparatus and method for processing a ranging channel in an OFDMA system. The apparatus converts received ranging complex signals to polar coordinate signals having a signal magnitude and a phase, and the received converted signals are each represented by a signal magnitude component and a phase component. A predetermined phase component of a signal according to a phase rotation is used to estimate a time delay by an addition operation of the phase of the received signal and the phase according to the phase rotation. Accordingly, the time delay and the power of each reverse link user of the OFDMA mobile communication system can be calculated by arithmetic operations of addition components instead of multiplication components, resulting in the reduction of complexity.
摘要:
Disclosed is an apparatus for generating a ranging pseudo noise (PN) code used in a base station of a portable internet system of an orthogonal frequency division multiplexing access scheme, wherein a ranging pseudo noise mask value is generated using a cell ID number, and then the generated ranging pseudo noise mask value is stored in a memory. A final ranging PN code is generated using the stored ranging PN mask value and a status of a pseudo random binary sequence for generating a ranging PN code. With such a structure, the maximal 256-numbered ranging PN code values can be obtained simultaneously with each 144 bit-length.
摘要:
Disclosed is an apparatus and method for processing a ranging channel in an OFDMA system. The apparatus converts received ranging complex signals to polar coordinate signals having a signal magnitude and a phase, and the received converted signals are each represented by a signal magnitude component and a phase component. A predetermined phase component of a signal according to a phase rotation is used to estimate a time delay by an addition operation of the phase of the received signal and the phase according to the phase rotation. Accordingly, the time delay and the power of each reverse link user of the OFDMA mobile communication system can be calculated by arithmetic operations of addition components instead of multiplication components, resulting in the reduction of complexity.
摘要:
Disclosed is an apparatus for generating a ranging pseudo noise (PN) code used in a base station of a portable internet system of an orthogonal frequency division multiplexing access scheme, wherein a ranging pseudo noise mask value is generated using a cell ID number, and then the generated ranging pseudo noise mask value is stored in a memory. A final ranging PN code is generated using the stored ranging PN mask value and a status of a pseudo random binary sequence for generating a ranging PN code. With such a structure, the maximal 256-numbered ranging PN code values can be obtained simultaneously with each 144 bit-length.
摘要:
When a base station of a time division duplex based mobile communication system receives an initial ranging request signal from a subscriber station, the base station generates initial ranging information including delay time information to the subscriber station, and receives uplink data delayed and transmitted using a delay time from the subscriber station. Also, when the subscriber station transmits an initial ranging request signal to the base station and receives initial ranging information including delay time information from the base station, the subscriber station establishes a transmission parameter value by using the transmission parameter value included in the initial ranging information and transmits uplink data by using the established delay time.
摘要:
In the uplink of an OFDMA system, a preamble is used to estimate a channel and then the pilot tones of a data symbol are used for channel estimation to update the channel estimate. The channel estimate is used for channel compensation, and the phase of the channel is corrected using the channel estimate obtained from the pilot tones. In this way, the channel estimation performance and hence the compensation ability can be enhanced.
摘要:
In a frequency offset estimating device of a subscriber station of a communication system in which a plurality of sectors are allocated to a cell, the frequency offset estimating device extracts a preamble sequence from a downlink frame signal. The frequency offset estimating device estimates a phase offset of a sector to which the subscriber station belongs among the sectors by using the preamble sequence, and calculates the autocorrelation value for the respective signals of the preamble sequence. The frequency offset estimating device compensates the autocorrelation value by using the phase offset, and estimates a frequency offset from the sum of the phase offset compensated autocorrelation values.
摘要:
In a frequency offset estimating device of a subscriber station of a communication system in which a plurality of sectors are allocated to a cell, the frequency offset estimating device extracts a preamble sequence from a downlink frame signal. The frequency offset estimating device estimates a phase offset of a sector to which the subscriber station belongs among the sectors by using the preamble sequence, and calculates the autocorrelation value for the respective signals of the preamble sequence. The frequency offset estimating device compensates the autocorrelation value by using the phase offset, and estimates a frequency offset from the sum of the phase offset compensated autocorrelation values.
摘要:
Disclosed is an apparatus for acquiring initial frame timing in a communication system having a normalizer that calculates a normalized window power from powers of samples of received signal during a monitoring period, a cross power calculator that calculates a window cross power from cross powers of the samples during the monitoring period, and each cross power corresponds to multiplication of two of the samples, a divider that divides the window cross power by the normalized window power and outputs a metric for a sample corresponding to the monitoring period, and a peak-value detector that searches a sample having the maximum value among metrics for the samples of the received signals during a predetermined period, and the metrics are calculated by shifting the monitoring period, with a sample next to the sample searched by the peak-value detector being determined as a starting point of a frame.
摘要:
The present invention relates to a method of detecting a space-time code in a mobile communication system. When detecting a space-time code B for a plurality of transmitting antennas, an ML (maximum likelihood) metric, which is generally calculated by using a specific structure of a matrix B, is defined as a new ML metric by reducing a variable of the ML metric. Two dependent sphere decoding processes are performed and an intersection of the decoding results is calculated, and a signal is detected from the ML metric. Therefore, since detection of the space-time code B for the plurality of transmitting antennas is performed by using the newly defined ML metric, an amount of matrix calculated can be reduced, and a calculation amount can be reduced by performing the two dependent sphere decoding processes. Further, since a detection order of symbols is changed according to a channel situation, it is possible to improve the performance of the system.