5.1 Geometric rep.of the sig waveforms 1.Review of the Vectors and Vector Space With the dot product (or inner product),denotes as'',a coordinate is calculated by following, 'e2=j a;=v.e +年=+：1+的 = Because, v= v.e;=(ae+ae2+...+avex).e; projection e:=i -a(ee:)+a(e2.e:)+...+a(e;e)...+av(ev.e;) =ax0+a,x0++a×0+aw×0 =a; orthonormal basis UESTC-Digital transmission through the AWGN channel Prof李晓峰 7