TRANSMITTER FOR MODULATING USING CYCLIC DELAY DIVERSITY AND RECEIVER FOR ESTIMATING RESIDUAL TIMIMING OFFSET OF OFDM SYSTEM

摘要

PURPOSE: A transmitter using an OFDM(Orthogonal Frequency Division Multiplexing) communication system and a receiver estimating a residual timing offset are provided to prevent the degradation of symbol timing offset estimation performance. CONSTITUTION: An OFDM communication system includes a transmitter(100) and a receiver(200). The transmitter includes a selector(110) and a cyclic delay unit(130). The selector selects an optimum cyclic delay value for a plurality of symbols to be transmitted through a transmission antenna. The cyclic delay unit performs the cyclic delay of an OFDM signal according to the cyclic delay value selected by the selector, and transmits the cyclic-delayed OFDM signal using a transmission antenna. The receiver includes a fast Fourier transform unit(210), a pattern selector(230) and an estimator(250). The fast Fourier transform unit transforms and demodulates a cyclic-delayed receiving signal transmitted from the transmitter from a time domain axis to a frequency domain axis. The pattern selector estimates a subcarrier pattern processed in the fast Fourier transform unit. The estimation unit estimates a residual symbol timing offset by calculating phase values rotated through auto correlation on the basis of the pilot subcarrier pattern estimated by the pattern selector and the cyclic delay value of the receiving signal. [Reference numerals] (100) Transmitter; (110) Selector; (130) Cyclic delay unit; (200) Receiver; (210) Fast Fourier transform unit; (230) Pattern selector; (250) Estimator