Tail-biting convolutional codes has been used in physical broadcast channel and physical downlink control channel of LTE, this paper introduces the architecture of the convolutional encoder and physical broadcast channel used in LTE, elaborating two common Viterbi algorithm, then a new CVA-based improved scheme is proposed, and in Physical broadcast channel system simulation is carried out. The conclusions indicate that the tail-biting convolutional codes can meet the requirements of LTE channel. Furthermore, the result proved that the double traceback Viterbi algorithm process improves the error performance.