diff options
Diffstat (limited to 'chapter07/content_ch07.tex')
| -rw-r--r-- | chapter07/content_ch07.tex | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/chapter07/content_ch07.tex b/chapter07/content_ch07.tex index e436e1a..f332b10 100644 --- a/chapter07/content_ch07.tex +++ b/chapter07/content_ch07.tex @@ -1887,6 +1887,16 @@ However, not each $L_1$ code is orthogonal to any $L_2$ code. The relation of or \label{fig:ch07:ovsf_code_tree} \end{figure} +The rules for creating the \acs{OVSF} code tree are (derived from the construction rules of the Hadamard matrix):
+\begin{itemize}
+ \item The parent node in the tree is $\vect{C}_{n,k}$ ($n$ is the code length, $k$ is the index).
+ \item The child nodes are:
+ \begin{itemize}
+ \item $\vect{C}_{2n,2k-1} = \left[\vect{C}_{n,k}, \vect{C}_{n,k}\right]$
+ \item $\vect{C}_{2n,2k} = \left[\vect{C}_{n,k}, -\vect{C}_{n,k}\right]$
+ \end{itemize}
+\end{itemize}
+ \subsection{Asynchronous \acs{DS-CDMA}} Welsh code have excellent cross-correlation properties. But, Welsh codes \underline{do not} have good autocorrelation properties. |