An efficient timing synchronization technique for FFT based multi-carrier direct sequence spread spectrum transceiver

An efficient timing synchronization technique for a low complexity FFT based multi-carrier direct sequence spread spectrum IF/baseband transceiver is presented. The timing synchronization control loop consists of a robust acquisition loop and a tracking loop that eliminates the timing phase offset caused by the transmission delay, sampling error, and channel noise. The acquisition loop reduces the probability of false lock by continuous threshold checking and adjusting process. Both the acquisition and the tracking loop incorporate a simple feedback mechanism for a practical VLSI transceiver implementation. The effect of the sampling offset on the performance of the timing acquisition is discussed. The highest operating speed of the receiver is the Nyquist sampling rate, but the entire synchronization is performed using the low speed baseband signals. The performance of the synchronization under an additive white Gaussian noise channel is assumed.