Patent ID: 8295311

Claim:
A method for detecting a pilot pattern, comprising a pilot signal s p (t), t=time, in a received signal r(t) implemented in an Orthogonal Frequency Division Multiplexing (OFDM) system, said method comprising: computing a value of a log-likelihood function Λ(τ 0 ,ν 0 ), τ=delay, ν=Doppler shift, for a hypotheses space specified by the pilot signal s p (t) and an initial time frequency offset (τ 0 ,ν 0 ), said log-likelihood function defined by: Λ ⁡ ( τ 0 , ν 0 ) = ∫ 0 ν max ⁢ ∫ 0 τ max ⁢  I ⁡ ( τ + τ 0 , ν + ν 0 )  2 ⁢ ⁢ ⅆ τ ⁢ ⁢ ⅆ ν where I ⁡ ( τ , ν ) ⁢ = Δ ⁢ ∫ r ⁡ ( t ) ⁢ s p * ⁡ ( t - τ ) ⁢ ⅇ - j ⁢ ⁢ 2 ⁢ ⁢ π ⁢ ⁢ ν ⁢ ⁢ t ⁢ ⅆ t where I(τ,ν) is a delay-Doppler image, r(t) is the received signal including the pilot pattern, and s* p (t) is a hypothesized pilot signal, and relating the computed value to a reference value to detect the pilot pattern.