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| author | Philipp Le <philipp-le-prviat@freenet.de> | 2020-06-30 17:06:54 +0200 |
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| committer | Philipp Le <philipp-le-prviat@freenet.de> | 2021-03-04 22:44:39 +0100 |
| commit | c1db4510292b388c228d8d8dab18c6d09cc869ba (patch) | |
| tree | 9a94765f384bff98d71fd490336783be6b5e6503 | |
| parent | b0307201182f7222402b8d767fd851ce5b9434fd (diff) | |
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Note on relation of number of users and OVSF code length
| -rw-r--r-- | chapter07/content_ch07.tex | 14 | ||||
| -rw-r--r-- | main/chapter07.tex | 4 |
2 files changed, 14 insertions, 4 deletions
diff --git a/chapter07/content_ch07.tex b/chapter07/content_ch07.tex index 56871e7..82a4b01 100644 --- a/chapter07/content_ch07.tex +++ b/chapter07/content_ch07.tex @@ -1899,8 +1899,18 @@ The rules for creating the \acs{OVSF} code tree are (derived from the constructi The different code lengths have benefits and drawbacks. \begin{itemize} - \item Longer codes have lower data rates. But they have a higher processing gain and better noise immunity. Data decoding works in noisy environments with low \ac{SNR}. - \item Short codes give a higher data rate. However, the processing gain is less as well as the noise immunity. Data decoding may not work in noisy environments. A proper \ac{SNR} is required. + \item Long codes + \begin{itemize} + \item Long codes have lower data rates. + \item But they have a higher processing gain and better noise immunity. Data decoding works in noisy environments with low \ac{SNR}. + \item Furthermore, more users can use the transmission channel, because more orthogonal codes are available (see Figure \ref{fig:ch07:ovsf_code_tree}). + \end{itemize} + \item Short codes + \begin{itemize} + \item Short codes give a higher data rate. + \item However, the processing gain is less as well as the noise immunity. Data decoding may not work in noisy environments. A proper \ac{SNR} is required. + \item Less users can use the transmission channel, because less orthogonal codes are available (see Figure \ref{fig:ch07:ovsf_code_tree}). + \end{itemize} \end{itemize} \subsection{Asynchronous \acs{DS-CDMA}} diff --git a/main/chapter07.tex b/main/chapter07.tex index bfe7099..649e313 100644 --- a/main/chapter07.tex +++ b/main/chapter07.tex @@ -13,8 +13,8 @@ % Configuration \def\thekindofdocument{Lecture Notes} \def\thesubtitle{Chapter 7: Spread Spectrum and Multiple Access} -\def\therevision{1} -\def\therevisiondate{2020-06-06} +\def\therevision{2} +\def\therevisiondate{2020-06-30} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Header |