Design and Realization of an Autonomous Software-defined Radio

We introduce the design and implementation of an autonomous software-defined radio (A-SDR). A suboptimal parameter estimation architecture with low complexity is designed, including estimation of the symbol period and shaping factor, modulation-type classification, and carrier frequency estimation. The estimated results are delivered to a universal multi-mode demodulator, in which the clock of analog-to-digital conversion (ADC) is configured by both the estimated symbol period and the symbol timing jitter, the PLL with universal phase discriminating algorithm can lock onto the residual carrier signal for most types of modulation. Some experimental results are given, it is shown that our A-SDR can demodulate most MPSK and MQAM signals with seamlessly changed bit rates without any prior knowledge.