摘要:
Disclosed is an apparatus and a method for performing a cell search in a wireless communication system. A subscriber station calculates the power of subcarriers according to their positions in a preamble signal of a frequency domain and identifies a segment of a cell to which the subscriber station belongs. Then, the subscriber station correlates PN sequences, which correspond to the segment of the cell that has been identified, with the preamble signal of the frequency domain. Therefore, the number of calculations for determining correlation values in a cell search is remarkably reduced.
摘要:
Disclosed is an apparatus and a method for performing a cell search in a wireless communication system. A subscriber station calculates the power of subcarriers according to their positions in a preamble signal of a frequency domain and identifies a segment of a cell to which the subscriber station belongs. Then, the subscriber station correlates PN sequences, which correspond to the segment of the cell that has been identified, with the preamble signal of the frequency domain. Therefore, the number of calculations for determining correlation values in a cell search is remarkably reduced.
摘要:
Provided is a channel estimation apparatus and method. In the channel estimation apparatus, a channel estimator performs channel estimation onto a received symbol and output a channel estimation result. The channel estimation result is stored in an estimation buffer along with a channel estimation result compensated in a preamble phase compensator. The preamble phase compensator receives a channel estimation result for pilot subcarriers of a data symbol and a preamble channel estimation result from the estimation buffer, acquires a phase rotation value between them, and compensates the preamble channel estimation result with the phase rotation value. When FCH and DL-MAP are demodulated, pilot subcarriers in the Nth PUSC symbol have been used to estimate the channel of the Nth PUSC symbol.
摘要:
A method and apparatus are provided for adaptively allocating pilots in a pilot-aided channel estimation system. A multipath delay is measured between a base station (BS) and a mobile station (MS). A distribution density of pilots of a signal to be transmitted between the BS and the MS is controlled. When the multipath delay is large, the pilot distribution density is relatively raised. However, when the multipath delay is small, the pilot distribution density is relatively lowered. The pilot distribution density is adaptively controlled according to the multipath delay, such that resources are effectively utilized and throughput is improved.
摘要:
Disclosed is an apparatus and method for estimating a start point of a frame in a wireless communication system. The method includes the steps of receiving a frame and estimating the start of the frame by searching for an interval or point of time during or at which a correlation between preambles is at its maximum. At this time, to in order to estimate the start of the frame, a cyclic prefix is used. Thus, a correlation between a cyclic prefix and the last interval of a symbol, which is the same as the cyclic prefix, is calculated and an interval or point of time having the maximum correlation is estimated as the start point of the cyclic prefix. Therefore, the start point of the frame can be accurately estimated based on the start point of the cyclic prefix.
摘要:
A method and apparatus for processing time windowing to transmit a signal in a Broadband Wireless Access (BWA) communication system based on Orthogonal Frequency Division Multiple Access (OFDMA). A signal of a first interval included in a previous symbol prior to a current symbol is stored as a signal of a previous symbol interval. The current symbol includes a guard interval and an effective symbol interval subsequent to the guard interval. The current symbol is windowed by overlapping the stored signal of the first interval with a signal of a second interval included in the current symbol subsequent to the previous symbol. A windowed signal is transmitted.
摘要:
Provided is a channel estimation apparatus and method. In the channel estimation apparatus, a channel estimator performs channel estimation onto a received symbol and output a channel estimation result. The channel estimation result is stored in an estimation buffer along with a channel estimation result compensated in a preamble phase compensator. The preamble phase compensator receives a channel estimation result for pilot subcarriers of a data symbol and a preamble channel estimation result from the estimation buffer, acquires a phase rotation value between them, and compensates the preamble channel estimation result with the phase rotation value. When FCH and DL-MAP are demodulated, pilot subcarriers in the Nth PUSC symbol have been used to estimate the channel of the Nth PUSC symbol.
摘要:
A method and apparatus for processing time windowing to transmit a signal in a Broadband Wireless Access (BWA) communication system based on Orthogonal Frequency Division Multiple Access (OFDMA). A signal of a first interval included in a previous symbol prior to a current symbol is stored as a signal of a previous symbol interval. The current symbol includes a guard interval and an effective symbol interval subsequent to the guard interval. The current symbol is windowed by overlapping the stored signal of the first interval with a signal of a second interval included in the current symbol subsequent to the previous symbol. A windowed signal is transmitted.
摘要:
Disclosed is an apparatus and a method for transmitting/receiving synchronization mode information in a wireless communication system. A transmission apparatus in the wireless communication system includes a mode information creating unit for creating operation mode information based on a determined utilized bandwidth, and a preamble generating unit for outputting a frequency domain preamble signal including the created operation mode information. A reception apparatus includes a signal receiving unit for receiving a frequency domain preamble signal, a bandwidth determining unit for determining a utilized bandwidth, and a mode information detecting unit for detecting operation mode information from the frequency domain preamble signal according to the determined utilized bandwidth.
摘要:
A method and apparatus are provided for adaptively allocating pilots in a pilot-aided channel estimation system. A multipath delay is measured between a base station (BS) and a mobile station (MS). A distribution density of pilots of a signal to be transmitted between the BS and the MS is controlled. When the multipath delay is large, the pilot distribution density is relatively raised. However, when the multipath delay is small, the pilot distribution density is relatively lowered. The pilot distribution density is adaptively controlled according to the multipath delay, such that resources are effectively utilized and throughput is improved.