变换域通信系统中的一种分段迭代门限算法

变换域通信系统通过信道估计在变换域设计信号波形避开干扰,它没有采用载波调制,而是用一个类似噪声的基函数进行信息调制。针对采用小波分析的文献中均采用固定门限值剔除干扰,提出了一种分段迭代门限算法。经仿真验证,采用该门限算法的系统比采用1.2倍的噪声功率谱密度门限值的系统有更好的误码率性能:在10%、70%部分带宽干扰下,当J/E低于3dB时系统误码率性能改进约2dB,其他J/E下改进约1dB;在线性调频干扰下,当J/E低于7.5dB时系统误码率性能改进约1.5dB,其他J/E下改进约0.5dB。

The fundamental idea in transform domain communication system is to synthesize a smart adaptive waveform to avoid interference at the transmitter. Its communication waveform is designed in transform domain according to the estimation of electromagnetic environment and no carrier modulation is employed, but a noise-like basis function is used to modulate the data. Owing to the fact that choosing the fixed threshold value in the references at present, a kind of subsection iterative threshold algorithm rejecting the interference.is put forward. Compared with adopting 1.2 times noise power spectrum density threshold value, the new threshold algorithm can make the system＇s bit error rate performance better. Under 10% and 70% part bandwidth interference, the bit error rate of the system has an approximately improvement of 2dB when J/E is lower than 3dB and other J/E values with an approximately improvement of ldB. Under linear frequency modulation interference, the bit error rate of the system has an approximately improvement of 1.SdB when J/E is lower than 7.5dB and other J/E values with an approximately improvement of 0.5dB.