本文研究一种高效的通信方式,即相位调制的OFDM-FH通信系统.为了提高衰落信道下系统误码率性能,接收端采用最大比合并的分集接收技术.利用特征函数方法,推导该系统在加性高斯白噪声信道和瑞利衰落信道时系统误码率性能.给出误比特率与跳频频点数Nh,OFDM子载波数N和用户数Nu等参数之间的关系.理论分析和仿真实验结果表明,在相同参数条件下,基于相位键控调制的OFDM-FH多址接入系统与其它OFDM-FH通信系统比较,具有系统频带宽度占用少、误比特率低等优势.
In this paper,a spectrally efficient communications system is introduced,i.e.,the OFDM-FH communications system with PSK modulation scheme.In order to improve the system performance in fading channel,the maximum ratio-combining(MRC) diversity receiver is applied.Based on characteristic function method,the symbol error rate(SER) performance of the system is derived in additive white Gaussian noise and Rayleigh fading channels.The numerical results first indicate the relationship between SER and the parameters such as the size of frequency slots set,the number of OFDM subcarriers and the number of users.By the numerical and simulation results,the frequency resource of the proposed system is saved and the SER is decreased,in compared with other similar OFDM-FH communications systems.