An Optimized Transmission Power Control Method for Pulsed BeiDou Pseudolite Signals

ABSTRACT

This paper presents an optimized transmission power control moethod for BeiDou pseudolites (BPLs) signals. Because of the near-far problem, the signal coverage probability of the conventional power transmission control method is nearly 50 percent at 95 dBm. Any further increase in transmission power only results in a decrease in the probability. In order to mitigate the near-far problem, a dynamic power control method was applied to transmit the signal. According to the previous parameter setting, we transmitted 3 pulses with a setp-to-step power reductionof 8 dB. The simulation result shows that although the coverage probability is nearly 1.23 times higher, it suffers from a distinct decline when the distance exceeds 1.3 km. Based on the BeiDou signal properties, we investigated the optimal parameter setting for the BPLs. It is proved by the assessment results that the optimal parameter setting is 2 pulses with a setp-to-step power reductionof 15 dB. Compared with the previous setting, the optimized method delivers more stable signal coverage.

Keywords:

BeiDou pseudolites, the near-far problem, signal coverage probability, transmission power control, pulsing scheme.