Abstract:
In order to compensate the Doppler frequency drift and chip period variation of the BPSK-modulated telemetry receiver, a new all-digital-receiver structure is proposed. Both the carrier tracking algorithm and the timing tracking algorithm are studied. The stability conditions of both loops are also addressed. Simulations are employed to prove the feasibility of the algorithms and the receiver structure. Simulations show that the loop can still get acquisition and keep tracking even with the condition of 23 kHz initial frequency offset, 20 g acceleration, π/2initial carrier offset, and 5/8 chip initial code offset.