Space–Time Block-Coded ARTM CPM for Aeronautical Mobile Telemetry

This article explores the application of Silvester’s space–time block code to the multi-index continuous phase modulation called “ARTM CPM” in the IRIG 106 standard to solve the “two-antenna problem”—the use of two transmit antennas to provide full spatial coverage on an airborne test article and the accompanying self-interference due to different delays between the two transmit antennas and the ground-based receive antenna. A symbol-level encoding scheme is derived that allows the burst-based space–time block code to operate in a continuously streaming mode. The results show that the space–time block code can solve the two-antenna problem with differential delays, but that the differential delays generate a substantial increase in the computational complexity of the detector. Complexity-reducing techniques are applied and analyzed. The results show that the complexity reductions required to produce a practically realizable detector render the bit error probability performance sensitive to the differential delay. Numerical results are presented to quantify the performance loss due to the differential delay.