飞行试验遥测系统中相位噪声纠正算法

An algorithm of phase noise correction for telemetry system in flight test

针对航空飞行试验领域的关键环节——试飞遥测中存在遥测接收机的相位噪声会严重影响正交频分复用技术(orthogonal frequency division multiplexing,OFDM)系统信号质量的问题,该文提出一种改进的相位噪声纠正算法。该算法根据空地无线信道的特点,先对连续导频位置进行信道估计和补偿,以便更好地压制共同相位误差(common phase error,CPE)在信道系数中的残留,然后挑选符合要求的连续导频完成CPE的估计和纠正,再送入信道估计模块。通过理论分析、计算机仿真验证和实际应用效果可以看出,该算法能够较好地保证抑制相位噪声的范围和精度,有效降低系统的误码率,满足航空试飞领域的技术要求,而且算法复杂度不高,有一定的实用价值。

As the phase noise of telemetry receiver has a great impact on the performance of OFDM （orthogonal frequency division multiplexing） system in telemetry during flight test which is a key link in the field of aviation flight test, an improved algorithm of phase noise correction is presented in this paper. According to the features of wireless channel, the algorithm conducts channel estimation and compensation at the continuous pilots to control the CPE （common phase error） residues in the channel coefficients, and then select continuous pilots meeting requirements to finish CPE estimation and correction and send the data into channel estimation module. Theoretical analysis, computer simulation and actual flight test verification prove that the algorithm has good performance in ensuring phase noise suppression range and precision and effectively reducing system error rate. With low algorithm complexity, it satisfies the technical requirement of flight test and has certain practical values.