In general,Rake combination and demodulation are realized according t o pilot signals.For the ground-to-air communication datalink without pilot sig nals,how to realize Rake diversity reception is an issue worth depth research.T his paper presents a noncoherent solution.This solution uses the combination te chnique of serial-parallel mixed search and serial search to optimize the recei ver path search algorithm based on PN sequence code acquisition,uses the partiti on weighted method to greatly reduce the complexity of implementing receiver mul tipath combination and improve the performance of system.The simulation results show that it is an important means of overcoming channel fading and can increas e the overall performance of communication system and decrease the effects of weak area in ground-to-air communications.

海面属于强反射平面,如何在强反射信道中抑制多径分量,实现信号可靠传输,工程中已积累了许多经验和方法.本文从圆极化天线抑制反射信号的原理、使用和安装的角度出发,提出了在海面强多径传播环境下,采用圆极化天线可以改善图像传输质量.试验结果表明:该方法切实可行,效果明显.