High-precision Parameters Estimation Algorithm of Combined PRBC and LFM
Xiao Liu · Radio Engineering · 2014
In order to solve parameters estimation of combined pseudo-random binary phase code( PRBC) and linear frequency modulated( LFM) in the complex electronic warfare environment,a high-precision parameters estimation algorithm is proposed. First, the square of the received signal is computed to eliminate the PRBC,then the fast dechirp algorithm is adopted to obtain the initial frequency and modulation slope roughly,then a new set of LFM signals are constructed,they are multiplied with the original signal respectively,the initial frequency and modulation slope can be estimated accurately by searching the maximum among several groups of fast Fourier transform( FFT) maximum amplitudes,finally,the linear frequency modulation signal can be reconstructed and multiplied with the conjugated signal to remove the carrier wave. The signal's instantaneous frequency is calculated by multi-phase differences,the parameters such as code time width,code rate and coding sequence are estimated through the calculating of trip points. Simulation results show that this algorithm can improve the estimation accuracy of the parameters significantly.