A Two-step MF Signal Acquisition Method for Wireless Underground Sensor Networks

Signal acquisition plays a critical role on the bit error rate (BER) of a direct sequence spread spectrum (DS/SS) communication system working with low frequency. In this paper, we propose a new signal acquisition method. The acquisition process includes coarse matched filter (MF) location in the first stage and an accurate MF acquisition as a verification mode for the second stage. The performance metrics, including mean acquisition time (MAT) and power consumption, are accuracy. The results indicate that when the signal-to-noise ratio (SNR) keeping consistent, the MAT of the proposed method is less than the original one. When the SNR is around -5dB, the system mismatch rate is about 5.6 x 10(4), which takes only one percent of those achieved in the original acquisition algorithms. The two-step MF acquisition method is stable except its power consumption being a little higher than the original method.