Error probabilities for DS spreadspectrum systems using an ALE for narrowband interference rejection
Abstract
The effects of the leastmeansquares adaptive line enhancer (ALE) weight misadjustment errors on the bit error rate are investigated for a directsequence spreadspectrum binary communication system in the presence of strong narrowband interference. The converged ALE weights are modeled as the parallel connection of a deterministic FIR (finiteimpulse response) filter and a random FIR filter. The statistics of the random filter are derived, assuming the output of the random filter to be primarily due to the jammer convolved with the random filter weights. This output is shown to be nonGaussian and to cause significant error rate degradation in comparison to a Gaussian model. Error probability expressions are derived for the bit error rate, evaluated numerically, and compared to the corresponding error probabilities for a Gaussian model for the random filter output. For some typical system parameter values and error probabilities, it is shown that the Gaussian model yields performance results that are too optimistic by several decibels.
 Publication:

IEEE Transactions on Communications
 Pub Date:
 May 1988
 Bibcode:
 1988ITCom..36..588B
 Keywords:

 Adaptive Filters;
 Electromagnetic Interference;
 Error Analysis;
 Fir Filters;
 Probability Theory;
 Spread Spectrum Transmission;
 Algorithms;
 Least Squares Method;
 Mathematical Models;
 White Noise;
 Communications and Radar