摘要
研究了AN/TRC-170数字对流层散射通信系统中使用的二频交叠升余弦信号的特点,分析了方波、半余弦和升余弦信号的带宽与能量通过率的关系,得出了该信号形式的最佳频率配置。分析结果说明,AN/TRC-170对流层散射通信设备的窄带和宽度2种波形都实现了无串扰的带内两频无间隔紧密配置,其频率配置是合理的。提出了一种基于FFT/IFFT的数字分路滤波器的实现方案,解决了传统的FIR方法难以在高采样率下实现窄通带、陡过渡带低通滤波的问题,给出了试验结果。
The characteristics of two frequency-offset time-interleaved raised cosine pulses employed by AN/TRC-170 digital troposcatter communication system is analyzed. The relationship between bandwidth and passed-power-ratio for square pulse, half cosine and raised cosine pulse is studied in order to get an optimum frequency configuration for this type of signal. It＇s demonstrated that two carriers adjacent to each other without a guard band are employed in either AN/TRC-170＇ s wide band or its narrow band configuration, and this configuration is reasonable.A novel digital filters based on FFT/IFFT to separate each part of frequency in the pass band is proposed,which is much easier to be implemented than FIR even if the sampling rate is several tens of times of the pass band frequency, and the simulation is introduced to proves the designs.
出处
《无线电通信技术》
2008年第3期12-15,共4页
Radio Communications Technology
关键词
交叠升余弦
对流层散射通信
最优滤波器
调制解调
time interleaved raised cosine pulse
troposcatter communication
optimum filter
modem
