Reducing Mean Acquisition Time in Code Synchronization for Wireless Communications

This work investigates a new code acquisition technique for wireless communications in presence of cell correlation. Code synchronization must be addressed in the most rapid and efficient way: even a small misalignment can cause dramatic signal-to-noise ratio (SNR) degradation. Serial cell search is usually adopted for pseudo noise (PN) code acquisition to reduce the processing complexity in mobile terminals for spread spectrum (SS) communication systems. Unlike the simple case of one (timing) cell per chip, the detection variables between contiguous cells, for sizes less than one chip period, are not independent and possibly strongly correlated. We propose a new test that takes into account several correlated cells at once. Our numerical and simulation results show that our method drastically improves the conventional approach in terms of detection probability, allowing a significant reduction of the mean acquisition time in code synchronization for wireless communications. The performance improvement is obtained with a negligible increasing of the system computational complexity.