摘要
四类机码是传真通信中一种高压缩比的信源码,目前已被广泛采用。在接收端,由于传输信道噪声影响或是接收手段不同,有时会产生传输误码。由于没有线同步码,在译码过程中一旦出现误码,即使是一比特错误,也可能产生严重的误码扩散,导致后续报文无法恢复。针对随机错误和突发错误的滑动窗口纠错译码技术,能够有效地纠正窗口范围内的多比特错误。在误码较严重而无法纠正时,重新同步技术,可有效控制误码扩散,提高报文恢复质量。
Group 4 facsimile code is a kind of facsimile signal source codes with high ratio of compression. Now, it is widely applied. On receiving end, sometimes because transmission channel is disturbed or the receiving measure is different, transmission error may occurs. Because there is no line synchronized code, error diffusion is very serious when any error, even one bit error, occurs. To random and outburst errors, moving window error-correcting arithmetic can effectively correct multi-bit in moving window. If it fails because of serious transmission errors, resynchronization arithmetic is another effective method to control error diffusion and improve the quality of fax image.
出处
《计算机工程与设计》
CSCD
北大核心
2007年第20期5048-5051,共4页
Computer Engineering and Design
关键词
传真通信
信源码
误码扩散
滑动窗口
重新同步
facsimile communication
source code
error diffusion
moving window
resynchronization
