Definition
A binary symmetric channel with crossover probability p denoted by, is a channel with binary input and binary output and probability of error p; that is, if X is the transmitted random variable and Y the received variable, then the channel is characterized by the conditional probabilities
- Pr( Y = 0 | X = 0 ) = 1 − p
- Pr( Y = 0 | X = 1) = p
- Pr( Y = 1 | X = 0 ) = p
- Pr( Y = 1 | X = 1 ) = 1 − p
It is assumed that 0 ≤ p ≤ 1/2. If p > 1/2, then the receiver can swap the output (interpret 1 when it sees 0, and vice versa) and obtain an equivalent channel with crossover probability 1 − p ≤ 1/2.
Read more about this topic: Binary Symmetric Channel
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