Abstract:

Considering that there exist some disadvantages in the current telemetry and ranging system where high rate telemetry data and ranging signals are transmitted on two different frequency bands, a new technique based on frequency modulation+pseudonoise (FM+PN) is proposed to achieve simultaneous transmission for high rate telemetry data and ranging signals on one frequency band. The novelty lies in the fact that the PN ranging code is parasitic upon the FM telemetry signal so as to generate a parasitical modulated signal. The modulation and demodulation algorithms are first presented, and the signal spectrum and bit error rate performance of telemetry data and ranging precision are then analyzed in theory. The performance of the new FM+PN technique is acquired by simulation and appropriate parameters are recommended by comparing these results. The simulation results demonstrate that the proposed FM+PN technique can improve band efficiency obviously with just a little cost of bit error rate performance of telemetry data.