Digital Communications on a Pseudonoise Tracking Link Using Sequence Inversion Modulation

The factors which enter into digital communication over a pseudonoise tracking link are developed. The deterioration of tracking quality due to simultaneous use of the tracking link for communication is shown to be small. The communication bit error probability is shown to be the same as that for coherent phase shift keying of a sine wave carrier when the tracking link uses biphase carrier modulation and the receiver uses balanced demodulators. In addition, the pseudonoise link supplies the necessary data bit synchronization. Experimental results are presented from laboratory equipment where data rates up to 47 000 b/s were transmitted over a pseudonoise tracking signal suitable for high accuracy range measurement to 3300 km.