Asymmetric hexagonal QAM based OFDM system

OFDM (orthogonal frequency division multiplexing) has been widely used in wire and wireless communications, because of its efficient use of the frequency spectrum and good multi-path tolerance. However, the OFDM system is very sensitive to frequency offset and phase noise. In order to overcome this disadvantage, asymmetric hexagonal QAM is presented in this paper as a new modulation method to solve this problem. Without weakening the resistance to noise, an asymmetric hexagonal QAM based OFDM system is easy to get the sub-carrier frequency and it is more convenient for its synchronization. In this paper, the asymmetric hexagonal QAM based OFDM system is designed and simulated by SystemView. Then the simulation results are presented and analyzed; the properties of asymmetric hexagonal QAM and rectangular QAM are compared.