【摘要】 基于过采样Sigma -deltaADC的波束形成器直接利用过采样Sigma -deltaADC所产生的1bit码流的相位信息进行高质量的聚焦延迟-求和。但此1bit码流速率极高,一般不能直接用USB接口送到计算机进行波束形成等后续处理,须先将其进行无损压缩,即在降低码流速度的同时保留波束形成所需的相位信息。采用Huffman编码方式对高速1bit流进行压缩。结果表明,Huffman编码能实现一半以上的压缩,从而使1bit码流通过USB接口传送成为可能。更多还原

【Abstract】 The sigma-delta beamsums obtained by adding the delayed 1-bit coded RF echo signals are then processed through a decimation filter to produce final beamforming outputs. Such 1-bit code streams possess very high rate, so they must be losslessly compressed before being transferred into computer to perform beamforming. During the compression, the phase information of the 1-bit code streams must be kept. Huffman coding was used to compress these high rate 1-bit code streams in this paper. The results show that Huffman coding can provide over a 50% compression ratio, which makes the 1-bit code stream transferred by USB possible.更多还原