Research On Key Technology Of Augement Receiver In C Band

Nowadays, Represented by GPS, GNSS navigation products are in transient process from the military to civilian areas, even applied in the complex context about city of skyscrapers.indoor or tunnel etc. The Complex environment makes the GNSS signals received susceptible to blocking, noising and multi-path interference, and these factors change the amplitude and phase of the signal dramatically, thus signal attenuation is caused severely. According to the actual item requirement, the data received in C-band are analyzed rigorously. Considering the C-band signal own severely space link loss to be relatively weak, this article analysis and research on the enhanced high-sensitivity receiver.As an important part of the receiver, the sensitivity of the base-band signal processing module determines the performance of the receiver in the data receiving process, so the algorithm improvement of the base-band signal processing module is the key for improving the receiver sensitivity. Therefore, our research can be conducted as follow:The structure of the satellite signal, the working principle and process of the base-band processing module are introduced detailed, as a background knowledge complement to the signal generation and receiving.In the process of capturing weak signals, it is based on the parallel code-phase acquisition algorithm to improve the acquisition speed and precision. Besides, there are three fundamental accumulation algorithms to improved SNR(signal-to-noise ratio)-coherent integration?non-coherent integration and differential coherent integration. Based on the parallel code-phase acquisition algorithm, the article deliberated three integration algorithms to realize the algorithm improvement. The combination acquisition algorithm is put forward first, which is the combination of Coherent integration?non-coherent integration. Despite of the SNR improvement, this algorithm can also eliminate the effect of data transitions on the coherent integration. But the non-coherent integration introduced the square loss. So the differential coherent acquisition algorithm is taken forward to weaken the square loss which is the combination of Coherent integration?differential coherent integration. Following on, a ingenious differential coherent acquisition is raised to low the amount of computation. At last, the performance of the three improved method is analyzed from three aspects, which include the capture threshold, detection probability and time complexity. The actual simulation proved superiority of the ingenious differential coherent acquisition algorithm.In the process of signal tracking, the article introduced the working principle and structure of the carrier loop and code loop. Then, the actual navigation data is received to verify the validity of the algorithm?At last, a phase compensation method is proposed creatively, which takes both the left circular polarized antenna and the right circular polarized antenna to receive the weak satellite signal. This method can compensate and correct the electrode loss caused by the different antenna polarization between transmitting and receiving in CAPS, and double the signal energy finally.The hardware platform to realize the algorithm is showed and the specific steps for the software are given, which verified the accuracy of the method put forward in the article finally.