Korea Electronics Technology Institute

Jong Ho Paik

Dong Sun Kim

Jin-Woong Cho

Won Gi Jeon

Jung Wook Wee

Jeong Wook Seo

Ki Won Kwon

Cheol-Hee Park

Min-Chul Ju

Young Hwan You

The present invention relates to a method and apparatus for detecting STBC-OFDM signals in time-variant channels. The method includes a step of demodulating STBC-OFDM modulation signals into OFDM reception symbols using Fast Fourier Transform (FFT); a step of estimating a frequency response for each sub-channel; an STBC decoding step of calculating decision variables determining the A transmit data symbols that are transmitted during the B OFDM symbol periods for each sub-channel; and a step of determining the transmit data symbols based on the decision variables calculated at the STBC decoding step. In this case, the decision variables are calculated using a linear equation that allows a squared Euclidean distance from OFDM reception symbols, which are demodulated during the B symbol periods, to have a local minimum for each decision variable when the STBC encoding and the frequency responses estimated during the B OFDM symbol periods are applied.

Method and apparatus for detecting STBC-OFDM signals in time-variant channels

An apparatus for compensating a channel distortion in a Bluetooth system to process a received signal having access codes comprises a multiplier for multiplying the received signal by a previously obtained channel distortion compensation signal to thereby provide a multiplied signal; a demodulator for demodulating access codes of the multiplied signal to thereby output demodulated received access codes as a demodulated signal; a correlation detection circuit for detecting correlation values between the demodulated received access codes and the access codes of the received signal previously stored therein to detect a start point of the received signal, thereby providing detected access codes having corresponding correlation values greater than a predetermined threshold and providing an enable signal if there are one or more correlation values greater than the predetermined threshold; and a channel distortion compensation circuit for performing a channel distortion compensation based on the detected access codes and a reference signal obtained by re-modulating the access codes of the received signal in response to the enable signal to thereby provide a channel distortion compensation signal.

Apparatus for compensating a channel distortion in a bluetooth system

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Suwon, South Korea

Jong Ho Paik