Abstract: This paper analyses the multiple pulses PPK coded modulation characteristics, such as signal space, redundancy, ratio of data rates and band The caculation for ratio of data rates is given Under certain conditions, multiple pulses PPK has higher date rates than single pulse PPKand OOK, and it has not bandwidth spread Suitable parameter choice can space much larger redundancy than that of the multiple pulses PPK itself, and thus provide the capability of correct coded control.