零中频架构的CPFSK弹载遥测发射机设计

Design of CPFSK missile-borne telemetry transmitter based on zero if architecture

针对弹载遥测通信系统中频谱利用率低、设备体积大、可靠性差、设计复杂等问题,设计了一款采用高频谱利用率CPFSK调制方式的零中频遥测发射机。首先根据CPFSK调制方式将采编组帧后的2Mbit/s遥测数据信号完成指数为0.715的正交调制,调制后的数据在AD9364芯片内部进行插值滤波、上边频等处理后,经过放大电路由天线发射出去。最后通过搭载测试系统,测试射频调制信号的频谱、传输距离和误码率。发现输出信号具有带宽窄、频谱主瓣能量集中、旁瓣衰减较快等优点,传输距离可达20km以上。结果表明本设计的弹载遥测发射机具有体积小、复杂度低、可靠性高、频谱利用率高的特点,不仅满足弹载遥测系统的性能指标,还可应用于未来航天遥测遥控系统中。

Aiming at the problems of low spectrum utilization,large equipment volume,poor reliability and complex design in missile borne telemetry communication system,designs a zero intermediate frequency telemetry transmitter with high spectrum utilization CPFSK(continuous phase frequency shift keying)modulation.Firstly,according to the CPFSK modulation mode,the framed 2 Mbit/s telemetry data signal is subjected to orthogonal modulation with an index of 0.715.The modulated data is processed by interpolation filtering and upper edge frequency within the AD9364 chip,and then transmitted by the antenna through the amplifier circuit.Finally,the spectrum,transmission distance and bit error rate of the radio frequency modulation signal are tested by the test system.It is found that the output signal has the advantages of narrow bandwidth,concentrated energy of the main lobe spectrum and faster attenuation of the sidelobe,and the transmission distance can reach more than 20km.The results show that the designed missileborne telemetry transmitter has the characteristics of small size,low complexity,high reliability and high spectrum utilization.It not only meets the performance index of missile-borne telemetry system,but also can be applied to future aerospace telemetry and remote control system.