SYMBOL DETECTOR BASED ON FREQUENCY OFFSET COMPENSATION IN ZIGBEE SYSTEM AND SYMBOL DETECTING METHOD THEREOF

摘要

A symbol detector based on a frequency error correction in a zigbee system and a method for detecting a symbol using the same are provided to detect a symbol by estimating a frequency error and correcting the frequency error based on one symbol included in a preamble. A frequency error estimating unit(310) acquires a frequency error element existed in a receiving signal based on a specific symbol included in a preamble of the receiving signal packet. A multi delay differentiating filter(240) multi-delay-differentiates the receiving signal to a predetermined plurality of delay time. A multi frequency error correction unit(320) corrects a frequency error by calculating the frequency error element acquired by the frequency error estimating unit(310) and the receiving signal multi-delay-differentiated by the multi delay differentiating filter(240) with a complex conjugate. A plurality of multi correlators are calculated to be correlated in real number with the delay-differentiated PN sequence by the same scheme with the multi delay differentiating filter(240) to an output value of the multi frequency error correction unit. The plurality of multi correlators responds to a symbol of the receiving signal. A plurality of adders(340) adds the output values of the multi correlators. A maximum value selector(350) selects a maximum value of the output values of the plurality of adders(340).