InformationTheory

InformationTheory.Shannon.AWGN.JointlyTypicalSet

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AWGN jointly typical set #

The continuous jointly typical set for the AWGN channel coding theorem (Cover–Thomas).

Main definitions #

  • AWGNJointlyTypicalSet n P N ε — the jointly typical set on ℝⁿ × ℝⁿ cut out by three empirical power bounds.

Main statements #

AWGN jointly typical set #

def

InformationTheory.Shannon.AWGN.AWGNJointlyTypicalSet

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(n : ) (P N ε : ) :
Set ((Fin n) × (Fin n))

The AWGN continuous jointly typical set (Cover–Thomas).

On ℝⁿ × ℝⁿ, the joint typical set for an AWGN channel with input power P, noise power N, and slack ε > 0, consists of pairs (x, y) such that

  • (1/n) ∑ xᵢ² ≤ P + ε — input power within slack of P,
  • (1/n) ∑ (xᵢ - yᵢ)² ≤ N + ε — empirical noise power within slack of N,
  • (1/n) ∑ yᵢ² ≤ (P + N) + ε — output power within slack of P + N.

For n = 0 the constraints are vacuous and the set is Set.univ.

Equations
  • One or more equations did not get rendered due to their size.
Instances For
    Used by
      theorem

      InformationTheory.Shannon.AWGN.mem_AWGNJointlyTypicalSet

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      @[simp]
      {n : } {P N ε : } {p : (Fin n) × (Fin n)} :
      p AWGNJointlyTypicalSet n P N ε i : Fin n, p.1 i ^ 2 n * (P + ε) i : Fin n, (p.1 i - p.2 i) ^ 2 n * (N + ε) i : Fin n, p.2 i ^ 2 n * (P + N + ε)

      Membership in AWGNJointlyTypicalSet unfolded.

      Used by
        theorem

        InformationTheory.Shannon.AWGN.AWGNJointlyTypicalSet_zero

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        (P N ε : ) :

        Trivial case: at n = 0, every pair is jointly typical.

        Used by
          theorem

          InformationTheory.Shannon.AWGN.AWGNJointlyTypicalSet_subset_of_le_ε

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          (n : ) (P N : ) {ε₁ ε₂ : } ( : ε₁ ε₂) (hn : 0 n) :

          Monotonicity in the slack ε: a larger slack admits more pairs.

          Used by
            theorem

            InformationTheory.Shannon.AWGN.AWGNJointlyTypicalSet_measurable

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            (n : ) (P N ε : ) :

            Measurability of the AWGN jointly typical set (Borel measurable as a finite intersection of polynomial sub-level sets on the product space).

            Used by