Posdata Company Ltd.

Joonsang Choi

Jaehyeong Kim

Jungnam Yun

The present invention relates to an apparatus for estimating and compensating a carrier frequency offset, and a data receiving method in a receiver of a wireless communication system. The apparatus correlates a received signal with a signal delayed by a predetermined period of the received signal in a correlation window, wherein the correlation window is set based on a Cycle Prefix (CP) and a preamble repetition length from a predetermined position, converts the correlated value into a phase value, compensates a phase of the converted result according to preamble segment numbers, and estimates an initial carrier frequency offset value.

Apparatus for estimating and compensating carrier frequency offset and data receiving method in receiver of wireless communication system

A method of detecting a frame boundary of a received signal in a digital communication system, the method including: generating a delayed signal by delaying the received signal by a predetermined period; calculating a correlation value by correlating the received signal with the delayed signal for a predetermined correlation length in a time domain; and determining a timing index corresponding to a maximum value, as a frame boundary index, from a plurality of correlation values which are obtained by repeating the calculation. According to an embodiment of the present invention, a correlation calculation in a time domain is performed without oversampling, in a limited length including a cyclic prefix. Accordingly, accuracy of frame boundary detection may be improved and complexity of hardware and software may also be reduced.

Method of detecting a frame boundary of a received signal in digital communication system and apparatus of enabling the method

An apparatus for searching for a cell in a mobile communication system, including: a preamble sequence storage unit storing preamble sequences each of which corresponds to one preamble index, and a cell searching unit correlating a received signal and the stored preamble sequences in a time domain and identifying the preamble index corresponding to the received signal. The cell searching apparatus correlates a received signal and stored preamble sequences in a time domain. The apparatus employs binary quantization of preamble sequences to reduce calculation and memory size. Also, the stored preamble sequences are phase pre-rotated according to a segment number, to prevent from a burden of frequency offset correction caused by three different hypotheses. Accordingly, a complexity of the cell searching apparatus is reduced and cell searching performance becomes more accurate.

Method and apparatus for searching cells utilizing down link preamble signal

A likelihood metric calculation method including: estimating a channel of a received signal and generating a channel estimate; compensating a channel of the received signal according to the channel estimate; calculating a region variable according to the channel estimate; and comparing the region variable and a magnitude of the compensated received signal and calculating a likelihood metric of the received signal according to a result of the comparison. An apparatus for calculating a likelihood metric including: a channel estimation unit estimating a channel of the received signal and generating a channel estimate; a channel compensation unit compensating a channel of the received signal according to the channel estimate; a region variable calculation unit calculating a region variable according to the channel estimate, the region variable being a value obtained by scaling a symbol coordinate value in a signal constellation corresponding to the received signal utilizing the channel estimate; a comparison unit comparing a magnitude of the compensated received signal and the region variable; and a bit metric calculation unit calculating a likelihood metric with respect to each bit of the compensated received signal according to a result of the comparison. According to the present invention, it is possible to reduce a complexity in the compensating of the channel and the calculating of the likelihood metric. Also, since effects caused by the channel variation are reflected as a weighting factor in the calculating of the likelihood metric, it is possible to improve a message detection performance of the entire system.

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Seoul, South Korea

Joonsang Choi