Research On QPSK Signal Parameters Estimation Methods And DSP Implementation

Communication signal processing is a very important technology especially in the environment of wireless communication. All the time, Scholars in various countries are constantly exploring the modulation signal, with the deepening of research, the modern communication technology has not only applied to our life, but also plays an increasingly important role in the military field. Parameters estimation of the modulation signal has a very important significance in intercepting enemy communications signals, electronic warfare, secure transmission of information and so on. And in many of the parameters, the carrier rate and symbol rate are the most important, the accurate estimation of them is of extraordinary significance in communication countermeasure. Carrier frequency estimation is the basis for the receiver to demodulate signal, in the implementation of radio communication interference, symbol rate is the basis to select the interference parameters and interference patterns, and at the same time, the symbol rate estimation is also a prerequisite for the blind identification and blind demodulation of communication signals. Therefore, this paper mainly studies the carrier frequency and symbol rate estimation for modulated signals.For the estimation of MPSK signal carrier frequency, it used the method of M to the power spectrum estimation and power spectrum estimation, and compared the direct power spectrum estimation method and smooth power spectrum method and made the analysis and simulation. For symbol rate estimation, it adopted the method of second wavelet transform and delay multiplication and made a concrete analysis and detailed algorithm simulation of delay multiplication, the delay multiplication method is mainly through the detection code rate of the peak spectral lines to estimate symbol rate. The result shows that this method in a larger signal-to-noise ratio range can estimate symbol rate accurately and is not sensitive to noise. Firstly, this paper made the algorithm simulation for carrier frequency and symbol rate estimation methods in the MATLAB environment, verified the correctness of the methods and further developed a related C program for the fourth spectrum QPSK signal carrier frequency estimation algorithm, eventually, achieved soft simulation under the TMS320VC5416 development environment--- CCS3.3 and verified the feasibility of the algorithm.