Downlink time acquisition and tracking for a man portable MDR terminal

A downlink time acquisition and tracking algorithm is described which is currently being used in development hardware for a man portable medium data rate (MDR) MILSTAR terminal. This algorithm incorporates the unique aspects of the hardware and provides rapid time acquisition sufficient for demodulating the highest burst rate of the MDR waveform. After describing the salient features of the MDR downlink processor, a discriminator design is presented. It is shown that this discriminator provides near linear performance for time errors in the region of interest. The tracking loop is then presented with its linear approximation. Experimental results are given which provide examples of the algorithm performance