地空测控链路OFDM信道估计

针对无人飞行器大动态运动特点,提出利用地空测控窄带扩频链路的信道估计,辅助OFDM传输方式的下行宽带链路进行信道估计的方法。基于OFDM信道估计基带模型,设计了奇偶OFDM符号分组交错导频插入方式,设计了基于窄带链路多普勒频偏、多径时延信道估计的宽带链路信道估计算法。在大多普勒与多径传输信道下对算法误码率性能进行了仿真,验证了下行宽带链路具有较强的抗大多普勒、抗多径衰落的性能。

OFDM Channel Estimation for Terra-air TT&C Link

Aiming at the fast movement of UAV,we proposed a novel OFDM channel estimation of terra-air wideband downlink using channel estimation result of terra-air narrowband spread-frequency link.Based on the baseband model for OFDM channel estimation,we designed a special pilot insertion pattern with alternative odd-even signs.and a wideband channel estimation algorithm based on the estimated frequency-offset and time-delay.Finally,on the multi-path channel with large Doppler,we implemented the bit-error-rate performance simulation for the new algorithm.The results indicate that the new method provides good performance in mitigating large Doppler effect and multi-path fading.