Research On Parameter Estimation Methods Of Digital Communication Signal

The communication countermeasure techniques is playing important role both in military and civilian field, in which the parameter estimation of digital communication signals and the jamming techniques have being an important research field. This paper primarily investigates the parameter estimation of digital communication signals including OFDM signal, the main works can be summarized as follows:Aiming at the carrier estimation problem at lower SNR in spread-spectrum and anti-jamming communication, used a special cyclic cumulants educed by a subclass of the high-order cyclic moments. Because of the low search speed and the search range was hardly quantified, we used corner detection algorithm based on a definite integral of power spectrum. The latter method was faster but not as accurate, so we used the power spectrum method to rough estimate, and the high-order cyclic moments to fix position, the modified method was preferable to hardware implementation. Some important parameters of OFDM signals were estimated based on autocorrelation, which include symbol rate, subcarrier-number, carrier frequency, bandwidth and subcarrier-frequency.Finally, the proposed algorithm was verified on the hardware platform based on the PXI wideband receiver. The results proved that, without any priori information, the parameters of digital communication signals including OFDM signal could be estimated even in low SNR conditions by using only receiving antenna output signals, which realized completely blind reconnaissance.