The rapid development of LEO constellations provides favorable conditions for the realization of global high performance navigation enhancement services. Focusing on the application requirements of high precision real-time positioning navigation in emerging application scenarios such as unmanned driving, this paper introduces a new signal enhancement technology based on LEO satellites, aiming at the practical problems such as limited coverage, insufficient channel capacity, low landing power, etc. The principle of cyclic code shift keying is deeply analyzed. A novel modulation based on chip or code period time division multiplexing is proposed. The signal characteristics are analyzed from different dimensions, and modulation verification is also carried out. The results show that the multiple code shift keying modulation can effectively improve the transmission rate of enhanced navigation information, which is feasible in engineering implementation, and can provide important support for the enhancement of navigation based on low orbit and the realization of minute-level fast and precise positioning in centimeter-level.