The Design Of Shipborne Range Finder Signal Processing Hardware Platform

In the long baseline positioning system composed with the shipborne range finder and subsea transponder array, the shipborne range finder is responsible for considerable signal processing task,including identifying different transponder signals,precisely estimating time of arrival of the signals,intersection solving as well as transmitting array calibration and remote control command. With the improving position accuracy, measuring range and other indexes, shipborne range finder calls for stronger signal processing. Focusing on the positioning system adopting long-term correlation of wideband signal for time estimation, a hardware signal processing system of the shipborne range finder which has great data-handling capacity is designed in the paper.On the basis of analyzing the development of existing hardware signal processing platforms, the proposed system employs computer coupled with expansion boards as the signal processing structure. Two expansion boards which are PCI interface transceiver control board and PCIE interface signal processing board. With FPGA as its core chip, PCI interface board controls the transmission and reception of data, and fulfills the task of signal preprocessing including multichannel band-pass filtering and down-sampling. In addition, the filter structure is simplified by directly band-pass filtering the single-bit output data of Σ△AD, for economizing on logic resources. PCIE interface signal processing board is composed of C6678 kernel board and PCIE adaptor board. The C6678 processor with 8 cores and 1.25G dominant frequency is responsible for mass data computation. The AMC interface adopted in C6678 is adapted to PCIE interface with the PCIE adaptor board. The signal integrity for the adaptor board is simulated with Hyperlinx in the paper. Loading DSP application program and transmitting and receiving data through PCIE interface, the signal processing board accomplishes the further data-handling.Finally, the function and performance of each system component is verified and tested,and results show that the designed system has achieved the target. Especially, the proposed shipborne range finder signal processing hardware system is of great data-handling ability with the data preprocess in FPGA and strong computation capability of C6678, which lays solid foundation for the corresponding signal processing algorithm implementation.