Design and evaluation of a new data modulation and channel coding scheme for eLoran system

Enhanced Loran system (eLoran) is an important source of precise time-frequency information and an effective backup of global satellite navigation system.Aiming at the problems of single modulation mode and low data transmission rate of eLoran signal and in order to make full use of the time-frequency resources,expand the amount of data broadcast and application range,this paper proposes a modulation method to improve the carrying ability of signal information and a channel coding method with higher coding gain.The transmission rate of 40~200 bps can be achieved by adding the pulse group that only used for data transmission in the novel modulation mode.The simulation results show that LDPC coding can give better consideration to both coding gain and signal frame length when the length of data information is about 215 bit.