Korea Electronics Technology Institute

Jin-Woong Cho

Cheol-Hee Park

Min-Chul Ju

Yong-Soo Cho

Jong-Ho Paik

Young-Hwan You

Myoung-Jin Kim

Yong-Bae Dhong

Hyung-gi Kim

Yun-Jae Won

Kyeung-Hak Seo

Jong Ho Paik

Young Hwan You

Hyung-Keun Lee

Won-Young Yang

Sung-Jin Kang

Hyoung-Kyu Song

Jang-Yeon Lee

Dae-Ki Hong

Hyeon-Seok Lee

Kee-Hyun Park

A joint detection-decoding receiver using a multistage parallel interference canceller for selectively estimating a partial codeword corresponding to a state transition (branch) is disclosed. The JDD receiver of the DS-CDMA system includes a PIC that employs a state sequence to selectively carry out a symbol estimation of a partial codeword corresponding to the branch so as to reduce complexity and a calculation load as well as maintaining a high performance of the receiver according to the joint detection-decoding.

Joint detection-decoding receiver of DS-CDMA system

A constant amplitude coded bi-orthogonal demodulator demodulates the received constant amplitude bi-orthogonal modulated data, cancels the parity bits to generate the serial data, detects the occurrence of an error by dividing the demodulated data into a plurality of groups of data, outputs the serial data as demodulated data if an error does not occur, sequentially converts bit polarities of data of groups in which an error occurs if the error detector detects the error, compares distances between the received bi-orthogonal modulated data and the constant amplitude coded bi-orthogonal modulated data, and selects, as demodulated data, data of which corresponding bit polarities are changed according to the comparison results. According to the present invention, power consumption is reduced, a power amplifier can be manufactured at an inexpensive cost, interference robustness can be ensured, and data can be transmitted at a high transmission rate and a variable transmission rate.

Apparatus for constant amplitude coded bi-orthogonal demodulation

The present invention relates to an adaptive frequency hopping apparatus in a wireless personal area network (WPAN) system, wherein predetermined packets of data can be correctly transmitted by estimating the channel qualities of operating bands in advance and transmitting the packets through a proper band.

Adaptive frequency hopping apparatus in wireless personal area network system

Disclosed is a zipper type Very high bit-rate Digital Subscriber Line (VDSL) system which comprises a transmitter including an inverse fast Fourier transformer for performing an inverse fast Fourier transform on input data, and a cyclic extension adder for adding a cyclic extension for each symbol to the data output from the inverse fast Fourier transformer and outputting the data to a transmission channel; and a receiver including a cyclic extension remover for removing the cyclic extension from the data received through the transmission channel, and a fast Fourier transformer for performing a fast Fourier transform on the data output from the cyclic extension remover. The cyclic extension adder copies a first predetermined number of data starting from the leading part of the input symbol data received from the inverse fast Fourier transformer into a first cyclic suffix for removing interference between symbols and maintaining orthogonality between sub-carriers; adds the first cyclic suffix to the end of the symbol data; copies a second predetermined number of data subsequent to the first predetermined number of data into a second cyclic suffix for maintaining orthogonality between upstream and downstream; and adds the second cyclic suffix to the end of the first cyclic suffix.

Zipper type VDSL system

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

Disclosed is a method of estimating carrier frequency offset in an OFDM system. The method includes the steps of forming one OFDM symbol which has M repeated identical signal block, being a base sub-block; forming a 2 number of identical ith sub-blocks using an M/2 number of the M number of base sub-blocks as a unit; and estimating an ith carrier frequency offset &egr; using a correlation between two adjacent ith sub-blocks in the 8 number of the ith sub-blocks.

Method of estimating carrier frequency offset in an orthogonal frequency division multiplexing system

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Kyeonggi-do, South Korea

Jin-Woong Cho