Korea Electronics Technology Institute

Jong-Ho Paik

Yong-Soo Cho

Jin-Woong Cho

Yong-Bae Dhong

Hyung-gi Kim

Young-Hwan You

Won-Young Yang

Hyoung-Kyu Song

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

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

Growing community of inventors

Kyungki-do, South Korea

Jong-Ho Paik