Design and implementation of SAR raw data BAQ based on FPGA

SAR raw data rate is one of most important limiting factor of spaceborne SAR system, in this paper, a design method of SAR raw data real-time compression system based on FPGA is discussed in detail, which adopts Block Adaptive Quantization (BAQ) algorithm. By using less hardware logic resource, SAR raw data rate is reduced, and performance of this real-time compression system is enhanced greatly. In BAQ module, four-channel parallel processing logic architecture is designed to circulate the statistic of data block; the logic architecture of multipliers and comparers is optimized, and when time-division multiple BAQ modules mode is applied in both I and Q channels in multi-FPGA, the real time processing ability is enhanced geminately. Experiment indicates the highest clock is 149MHz, data throughput of single module is great than lGbps, and when compression ratio is 8/3, the signal distortion noise ratio (SDNR) is great than 14dB.