Fix N_C/N_V notation
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@@ -546,13 +546,15 @@ The \acp{vn} additionally receive messages \cite[5.4.2]{ryan_channel_2009}
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computed from the channel outputs.
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The consolidation of the information occurs in the \ac{vn} update
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\begin{align*}
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L_{i\rightarrow j} = \tilde{L}_i + \sum_{j'\in \mathcal{N}(i)\setminus
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j} L_{i\leftarrow j'}
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L_{i\rightarrow j} = \tilde{L}_i + \sum_{j'\in
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\mathcal{N}_\text{V}(i)\setminus
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\{j\}} L_{i\leftarrow j'}
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\end{align*}
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and the \ac{cn} update
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\begin{align*}
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L_{i\leftarrow j} = 2\cdot \tanh^{-1} \left( \prod_{i'\in
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\mathcal{N}(j)\setminus i} \tanh \frac{L_{i'\rightarrow j}}{2} \right)
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\mathcal{N}_\text{C}(j)\setminus \{i\}} \tanh
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\frac{L_{i'\rightarrow j}}{2} \right)
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.
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\end{align*}
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@@ -570,9 +572,9 @@ possible cycles and are thus especially problematic.
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A simplification of the \ac{spa} is the min-sum decoder. Here, the
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\ac{cn} update is approximated as \cite[Sec.~5.5.1]{ryan_channel_2009}
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\begin{align*}
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L_{i \leftarrow j} = \prod_{i' \in \mathcal{N}(j)\setminus i}
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L_{i \leftarrow j} = \prod_{i' \in \mathcal{N}_\text{C}(j)\setminus \{i\}}
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\sign \left( L_{i' \rightarrow j} \right)
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\cdot \min_{i' \in \mathcal{N}(j)\setminus i} \lvert
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\cdot \min_{i' \in \mathcal{N}_\text{C}(j)\setminus \{i\}} \lvert
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L_{i'\rightarrow j} \rvert
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.
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\end{align*}
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@@ -1568,7 +1570,7 @@ Additionally, we amend the \ac{cn} update to consider the parity
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indicated by the syndrome, calculating
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\begin{align*}
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L_{i\leftarrow j} = 2\cdot (-1)^{s_j} \cdot \tanh^{-1} \left( \prod_{i'\in
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\mathcal{N}(j)\setminus \{i\}} \tanh \frac{L_{i'\rightarrow j}}{2} \right)
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\mathcal{N}_\text{C}(j)\setminus \{i\}} \tanh \frac{L_{i'\rightarrow j}}{2} \right)
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.
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\end{align*}
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The resulting syndrome-based \ac{bp} algorithm is shown in
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@@ -899,8 +899,8 @@ To see how we realize this in practice, we reiterate the steps of the
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\right) \\[3mm]
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\text{\ac{cn} Update (Min-Sum): }&
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\displaystyle L_{i \leftarrow j} = (-1)^{s_j}\cdot \prod_{i'
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\in \mathcal{N}(j)\setminus \{i\}} \sign \left( L_{i' \rightarrow j}
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\right) \cdot \min_{i' \in \mathcal{N}(j)\setminus \{i\}} \lvert
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\in \mathcal{N}_\text{C}(j)\setminus \{i\}} \sign \left( L_{i' \rightarrow j}
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\right) \cdot \min_{i' \in \mathcal{N}_\text{C}(j)\setminus \{i\}} \lvert
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L_{i'\rightarrow j} \rvert \\[3mm]
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\label{eq:vn_update}
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\text{\ac{vn} Update: } & \displaystyle L_{i \rightarrow j} =
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