散射通信以其特有性能在无线通信领域发挥着重要作用,但存在传播损耗大、多径传输和衰落问题,基于交错正交幅度调制的正交频分复用系统(OFDM/OQAM)无需循环前缀,既具有传统正交频分复用系统(OFDM)抗多径干扰的优势,又利用滤波器组消除多径信道之间的符号间干扰(ISI)和载波间干扰(ICI),而无需保护间隔,提高了频谱利用率。建立了对流层散射信道抽头延迟线信道模型,分析了ICI和ISI的数学统计特性,将OFDM/OQAM系统与CP-OFDM/QAM系统进行对比。仿真分析表明:散射信道下OFDM/OQAM系统较传统的OFDM系统抑制ICI和ISI具有明显优势,误码率(BER)明显降低,为实现散射信道的高速率、大容量可靠通信提供了的方向指导。
Troposcatter communication plays an important role in wireless communication for its specific function. But it has the problem of big loss in transmission and multipath communication and fading. Offset-QAM based OFDM,without Cyclic Prefix,takes OFDM’s advantage of anti-multipath interference. It can eliminate inter-carrier interference and inter-symbol interference in multipath channels by filter-bank instead of guard interval to improve the utilization rate of frequency spectrum. The paper builds the tapped delay line model of the troposcatter channel and analyzes the mathematic statistic character of ISI and ICI. It makes a comparison between OFDM/OQAM and CP-OFDM/QAM. The simulation results demonstrate the advantage of OFDM/OQAM over traditional OFDM in the suppression of ICI and ISI in troposcatter channel. There is an obvious reduction of Bit Error Rate. The paper provides direction for the realization of high speed and large capacity and high reliability scattering communication.