Patent ID: 7215636
Filing Date: 2007-05-08
Classification: H04L

Abstract:
1. A method of determining a training signal in an orthogonal frequency division multiplexing (OFDM) system, the training signal being transmitted from an OFDM transmitter to an OFDM receiver using N subcarriers in order to allow the OFDM receiver to perform symbol synchronization, frequency synchronization, and channel estimation, the method comprising: determining a first training symbol by setting odd-numbered subcarriers to 0 in a frequency domain, obtaining even-numbered subcarriers using M-ary phase-shift keying (M-PSK), and performing differential modulation so that a change in the phase difference between remote two subcarriers is constant; and determining a second training symbol by setting even-numbered subcarriers to 0 in the frequency domain, obtaining odd-numbered subcarriers using M-PSK, and performing differential modulation so that a change in the phase difference between remote two subcarriers is constant.