Decoding $ p$-ary Hamming codes

Here's the decoding algorithm: Let $ y$ be the received vector. Let

$\displaystyle {\bf e}_1=(1,0,...,0), \ \
{\bf e}_2=(0,1,0,...,0), ...,
{\bf e}_n=(0,...,0,1),
$

be the standard basis vectors in $ \mathbb{F}_p^n$. Assume that $ y$ has $ \leq 1$ error.

(1) Compute $ y\cdot H^t$. This is an $ n$-tuple, so it must be of the form $ c\cdot {\bf s}$, for some $ {\bf s}\in S$ and some $ c\in \mathbb{F}_p^\times$.

(2) If $ {\bf s}$ is the $ i^{th}$ element of $ S$ then the decoded vector is $ {\bf y}-c\cdot {\bf e}_i$.

Exercise 3.9.9   Decode $ (0,1,0,0,0,0,1)$ in the binary Hamming code of §3.4.2 using this algorithm.

Exercise 3.9.10   Decode $ (0,0,1,1)$ in the $ 3$-ary $ (4,2,3)$-Hamming code of Example 3.9.5 using this algorithm.



David Joyner 2007-09-03