一种遥感卫星高码速VCM数传信道的均衡技术

An Equalization Technique for VCM Data Transmission Channel of Remote Sensing Satellite with High Data Rate

在基于第二代数字卫星视频广播协议(DVB-S2)标准的遥感卫星可变编码调制(VCM)高码速数传信道中,宽带信号的大失真、大频偏和低信噪比会导致解调器载波环路不锁定。传统的DVB-S2解调器并不能解决这个问题。在载波环路前增加一个均衡器补偿失真,可以让载波环路稳定锁定。为了克服载波环路前信号的频偏和相偏对均衡器的影响,提出了一种均衡技术,利用起始序列(SOF)和导频的先验信息进行双重自相关变换,设计了一种新的误差函数和迭代过程。仿真结果表明,该均衡技术可在该应用条件下支持解调稳定工作。

In European Digital Video Broadcasting-Satellite Second Generation(DVB-S2)based high-data-rate remote sensing satellite variable coding and modulation(VCM)data transmission channel,the high channel distortion introduced by broadband channel,high frequency offset and low signal-to-noise ratio(SNR)makes the carrier loop unlock.The conventional DVB-S2 based demodulator can忆t solve the problem.Placing an equalizer ahead of the carrier loop can compensate the distortion and stabilize the carrier loop.In consideration of the impact of frequency offset and phase offset on the equalizer,an equalization technique is proposed.It adopts self-correlation transform of prior information with a new error function and iteration process.The prior information comes from start of frames(SOF)and pilot.The simulation verifies that the new equalization technique supports the stable work of demodulation in this application.