在分析OFDM调制符号对称性的基础上,结合正交上下变频技术,提出了一种基于符号对称性的半符号OFDM (HS-OFDM)调制方法,分析了系统的误码性能和频谱效率,给出了一种抗多径干扰的调制符号设计方法,并对理论分析进行了仿真验证。该半符号调制方法适用于子载波采用BPSK或PAM调制的OFDM系统,可将系统的频谱效率极限值提高至2 Baud/Hz,为更高效调制技术的研究提供了一个突破口。
Based on the analysis of symbol symmetry of orthogonal frequency-division multiplexing (OFDM) modulation and by combining with quadrature up(down)-conversion technique, a half symbol OFDM (HS-OFDM) modulation method based on symbol symmetry is proposed. The BER performance, the spectral efficiency, and the transmission over multipath fading channels are analyzed. By using this method to an OFDM system modulated by binary phase shife keying (BPSK) or pulse amplitude modulation (PAM), the upper limit of the system bandwidth efficiency can be raised to 2 Baud/Hz.