A novel pseudo chaotic pulse position modulation（PCPPM） was proposed which was suitable for ultrawide-bandwith impulse radio communication systems

in this scheme

symbolic dynamics of a chaotic map was used for chaotic pulse position modulation（CPPM）

the separation between the adjacent pulses were determined by chaotic dynamics and binary information was modulated onto this carrier by the pulse position modulation method.System could acquire synchronization automatically without any specific "hand shaking"protocol.The advantages of PCPPM are decrease of the measurement precision of interpulse intervals and suitable for all digital solution.Since a random distribution of interpulse intervals

the resulting spectrum is a noise like spectrum.Finally

the performances of PCPPM were analyzed and simulated.