This paper deals with the implementation of an adaptive acquisition stage in a global navigation satellite - GNSS - receiver with a pilot and data channel in case of GNSS L5 signal. Adaptive acquisition decides on GNSS signal presence or absence by comparing a cell under test with an adaptive threshold and provides a code delay and Doppler frequency estimation. Firstly, we introduce an adaptive acquisition with a cell- averaging-constant false alarm rate - CFAR- for pilot channel then we propose a data-pilot fusion. At a second level, the proposed schemes are implemented on FPGA by using system generator and Xilinx tools.Theobtained results are summarized in the resource tables, which show that our implementation is feasible on the selected FPGA card.