Let HHH be a PCM for an (n,k)(n,k)(n,k)-code CCC over FFF. Let x∈Vn(F)x \in V_n(F)x∈Vn(F). The syndrome of xxx (w.r.t. HHH) is s=HxTs = Hx^Ts=HxT.
Input: PCM HHH and a received word r∈Vn(F)r \in V_n(F)r∈Vn(F).
Create a table of coset leaders and their syndromes.
Compute s=HrTs = Hr^Ts=HrT
Look up the coset leader corresponding to sss, say ℓ\ellℓ.
Decode rrr to c=r−ℓc = r - \ellc=r−ℓ.