Forward - Prof.Xu Mengxia(Research Center of Information Seienee; Peking University; Beijing; China) Prof.Yao Qingdong(DePt.Information and Eleetronies Eng.; Zhejiang University; Hangzhou; China) Prof.Gu Funian(DePt.Eleetronies Eng.; shanghai Jiaotung University; Shanghai; China) Prof.Yuan Baozhong(Researeh Inst.Information Seienee; Northern Jiaotung University; China) (SePtember 20; et al. (Tongxin xuebao)