无人机测控传输中SCCPM优化设计

针对无人机测控传输系统频率资源日趋紧张、电磁环境日渐复杂的现状,为提高无线传输频带效率和功率效率,在卷积码和CPM（Continuous Phase Modulation,连续相位调制）的基础上,提出一种基于SCCPM（Serially Concatenated CPM,串行级联CPM）的无人机遥控、遥测数据传输体制.通过引入Turbo（涡轮）码迭代原理设计CPM解调与卷积译码反馈校正结构,并对CPM解调算法进行优化以减小复杂度,得到相位连续、频谱紧凑、编码增益高、收敛特性好的无人机测控通信系统.仿真结果表明：所设计方案采用级联外迭代方式可获取更高的信噪比增益、更低的错误平层——与典型应用的RS（Reed-Solomon,里德-所罗门）码级联卷积码相比,该方案能够多获取1.6 dB的信噪比增益,表明SCCPM更适用于无人机测控数据传输.

Optimization Design of SCCPM in UAV Telemetry ＆ Control Transmission

A UAV （Unmanned Aerial Vehicle） telemetry ＆ control data transmission system using SCCPM （Serially Concatenated Continuous Phase Modulation） based on convolutional code and CPM （Continuous Phase Modulation） is presented as a viable solution to improve wireless transmission bandwidth efficiency and power efficiency under the reality of increasingly congested spectrum and complex electromagnetic environment. Turbo iterative principle is in troduced to design CPM demodulation and convolutional decoding feedback correction method. Simultaneously, CPM demodulation algorithm is optimized to reduce its complexity. As a result, a UAV telemetry ＆ control corn munication system which has continuous phase, compact spectrum, high code gain and good convergence character istics is obtained. Simulation results show that the proposed scheme adopting concatenated outer code iterative deco ding method has higher SNR （Signal-to-Noise Ratio） gain and lower error floor. More than 1.6 dB SNR gain can be got compared with the typical applications of concatenated RS code and eonvolutional code. The conclusion is that SCCPM is more suitable for UAV telemetry ＆ control data transmission.