Samsung Electronics Co., Ltd.

Yun-young Kim

Jae-Ho Roh

Jae-hyun Koo

Yeon-gon Cho

A sampling frequency offset estimation apparatus and method to be applied to an OFDM (orthogonal frequency division multiplexing) system are provided. The apparatus includes an ADC (analog-to-digital converter) sampling a received signal based on a predetermined sampling frequency; a FFT (Fast Fourier Transform) unit transforming the sampled received signal into a frequency domain; a phase calculator calculating phase shifts of pilot subcarriers of the sampled received signal which has been transformed into the frequency domain; a determiner calculating phase shift reaching times at which samples of the pilot subcarriers shift due to the phase shift; a time offset calculator calculating a sampling time offset using the pilot subcarriers, and a frequency offset calculator calculating a sampling frequency offset based on the phase shift reaching times and the sampling time offset.

Sampling frequency offset estimation apparatus and method for OFDM system

A sampling frequency offset tracking method in an orthogonal frequency division multiplexing (OFDM) system includes determining a search direction of maximum likelihood estimation (MLE) using a carrier frequency offset estimated using pilot subcarriers of a received signal; calculating a size of a MLE search region using a maximum sampling frequency offset of the OFDM system and a resolution of the MLE; calculating a range of the MLE search region for each OFDM symbol based on the size of the MLE search region; and tracking the sampling frequency offset by calculating a maximum correlation between the pilot subcarriers and reference pilot subcarriers within the MLE search region each OFDM symbol. Accordingly, the search region of the MLE is reduced according to the sign of the estimated carrier frequency offset. Therefore, the sampling frequency offset can be easily tracked and the estimation error can be reduced.

Sampling frequency offset tracking method and OFDM system using the same

A signal acquisition apparatus and method for reducing a false alarm rate are disclosed. The apparatus includes a comparator for detecting a first peak by comparing a correlation value of a received signal with a first threshold and detecting second peaks in a sample interval of the detected first peak based on a second threshold which is different from the first threshold. Thus, a signal is acquired based on a number of the detected second peaks. Accordingly, the false alarm rate due to the noise can be reduced while the detection probability is maintained even at a high SNR.

Signal acquisition apparatus and method for reducing false alarm rate

An apparatus and method applied to an orthogonal frequency division multiplexing (OFDM) receiver performs symbol timing synchronization by correlation between channel impulse responses. The apparatus applicable to the OFDM receiver, includes a channel impulse response (CIR) estimator for estimating a CIR of a present symbol from which a symbol timing is to be detected, using a previous symbol received prior to the present symbol; a matched filter for computing the CIR using the present symbol; a correlation calculator for calculating correlation between the estimated CIR and the CIR computed at the matched filter; and a peak detector for detecting the symbol timing by obtaining a timing offset between the estimated CIR and the computed CIR based on a maximum value of the calculated correlation.

Apparatus and method for synchronizing symbol timing synchronization applicable to orthogonal frequency division multiplexing (OFDM) receiver

A synthesis filter for an MPEG audio decoder, and a decoding method thereof. The synthesis filter for an MPEG audio decoder includes a butterfly computation part which performs a butterfly computation with respect to an input MPEG audio subband sample by a predetermined unit, a matrix computation part which performs a matrix computation using a result of the butterfly computation, a first buffer which stores a result of the matrix computation according to a predetermined address, a window computation address generation part which generates first and second addresses with respect to the first buffer to use for each cycle of the window computation, a window computation part which outputs the matrix computation result stored to the first and second addresses to perform the window computation, and an output part which outputs a result of the window computation.

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Suwon-si, South Korea

Yun-young Kim