Techniques for frame synchronization on unknown frequency selective channels

For burst oriented data transmission over frequency selective fading channels, the problem of optimum frame synchronization is discussed. A new criterion for frame synchronization accuracy is derived. In the following, we propose new algorithms that allow to estimate the frame start of a data packet transmitted over a noisy unknown dispersive fading channel. The algorithms are classified in data-aided and non-data aided algorithms. All techniques are successively derived from the ML criterion taking into account less and less information. Frame synchronization may be improved basing the frame start estimate on multiple frames. Solutions working under the constraint of clock inaccuracies are presented. The algorithms are compared using simulation. It is shown that a combination of power-ramp up and data-aided synchronization is best suited for asynchronous transmission. With minor modification, the algorithms may be used for multicarrier modulation as well.