Soft signal recognition and signature code acquisition with automatic frequency control in DS-SS systems

A novel signal recognition and signature code acquisition (SR/CA) method is proposed for DS-SS systems with frequency offset. The disadvantage of single decision threshold is pointed out for the existed SR/CA method via thoroughly analyzing the effect of frequency offset. The presented new method, which is called soft SR/CA, adopts double decision thresholds and automatic frequency control loop. The performance analysis and double thresholds set criterion are also discussed. Numerical results show that soft SR/CA method provides better detection performance, while false alarm probability hardly increases.