国家重点实验室 Channel Combining 0 Begin with N copies of W >Use a 1-1 mapping Gw:{0,1W→{0,1} UNA IN-1 >to create a vector channel UN W:UN→YW oCombining operation is lossless: >Let U.Uv i.i.d.-Unif.01 then X,.Xy i.i.d.~Unif.(01) >and C(W)=I(UN;YN) =I(XN:YN) =NC(W) 10Channel Combining Begin with N copies of W  Use a 1-1 mapping  to create a vector channel Combining operation is lossless:  Let then  and 10 :{0,1} {0,1 } N N GN → : N N WU Y N → 1,., i.i.d. Unif. {0,1} U UN  1,., i.i.d. Unif. {0,1} X X N  () (;) ( ; ) ( ) N N N N N CW IU Y I X Y NC W = = =