Analysis of a coherent frequencyhopped spreadspectrum receiver in the presence of jamming
Abstract
A digital phase/timing tracking loop for a coherent frequencyhopped spreadspectrum receiver is analyzed. A training period is introduced to aid the system in entering the tracking mode; then decisiondirected measurements are used. The Scurve, the conditional variance of the phase estimator, and the linear model of the loop are derived. Then the phase error is modeled as a homogeneous finite Markov chain, and the length of the training period and the approximate probability of entering the tracking range are obtained. By limiting the maximum output magnitude of the phase estimator, it is shown that the tracking performance is close to that for (1) coherent BPSK in the absence of jamming, or (2) perfect synchronization in the presence of partialband jamming. The meantime to loss of lock is shown to be several orders of magnitude larger than the expected length of training period.
 Publication:

IEEE Transactions on Communications
 Pub Date:
 May 1990
 Bibcode:
 1990ITCom..38..715S
 Keywords:

 Frequency Hopping;
 Jamming;
 Noise Spectra;
 Phase Shift Keying;
 Spread Spectrum Transmission;
 Phase Error;
 Radio Frequencies;
 Random Noise;
 Signal To Noise Ratios;
 White Noise;
 Communications and Radar