摘要 航天器上器件硬件资源和能量受限,对在测控系统中实现变速率解调所需的硬件资源提出了更高的要求。本文提出伪高倍速率解调和重复译码算法,在不降低采样率的情况下可实现不同符号率信号的解调。理论推导证明该方法可达到理想的解调误码性能,且耗费的硬件资源不到经典的DDC(Direct Digital Converter)芯片硬件资源的一半。计算机仿真和实际测试表明该方法能有效应用于微波统一测控系统的变速率解调。
Abstract:In spacecraft, hardware resources and energy are limited, which restricts the hardware consumption of the variable rate demodulation in Telemetry and Telecommand(TT&C) systems. This paper proposes an algorithm which accomplishes variable rate demodulation based on pseudo high datarate demodulation and repeated decoding without reducing the sampling rate. It turns out that the performance of the method is equivalent to the ideal result of variable rate demodulation, and the hardware consumption is less than half of that of the classical Direct Digital Converter (DDC) chips. Computer simulations and practical experiments show that the proposed method is effective for variable rate demodulation in TT&C systems.