Timing Recovery Methods for VSB Receivers

The most attractive characteristic of the Gardner´s method is the detected timing error is free from carrier offset if both arms of the transmitted complex signal are used. However, in VSB system, symbol information is mainly contained in I channel. Q channel is just a Hilbert transform of I channel. In this reason, most VSB receivers only use I channel signal for symbol timing recovery. It works well when carrier offset does not exist or negligible, but get worse if not. This paper presents another timing recovery method that is suitable for VSB receivers. Simulations show that the proposed method provides consistent performance regardless of carrier recovery status and it can estimate the timing error even at symbol rate´.