Linear code: Difference between revisions

Content deleted Content added
m Generalization: cite repair;
Generator and check matrices: consistent notation of min_
Line 17:
Linearity guarantees that the minimum [[Hamming distance]] ''d'' between a codeword ''c''<sub>0</sub> and any of the other codewords ''c''&nbsp;≠&nbsp;''c''<sub>0</sub> is independent of ''c''<sub>0</sub>. This follows from the property that the difference ''c''&nbsp;&minus;&nbsp;''c''<sub>0</sub> of two codewords in ''C'' is also a codeword (i.e., an [[element (mathematics)|element]] of the subspace ''C''), and the property that ''d''(''c'',&nbsp;c<sub>0</sub>)&nbsp;=&nbsp;''d''(''c''&nbsp;&minus;&nbsp;''c''<sub>0</sub>,&nbsp;0). These properties imply that
 
:<math>\min_{c \in C,\ c \neq c_0}d(c,c_0)=\min_{c \in C,\ c \neq c_0}d(c-c_0, 0)=\min_{c \in C,\ c \neq 0}d(c, 0)=d.</math>
 
In other words, in order to find out the minimum distance between the codewords of a linear code, one would only need to look at the non-zero codewords. The non-zero codeword with the smallest weight has then the minimum distance to the zero codeword, and hence determines the minimum distance of the code.