Patent ID: 8090581

Claim:
A method of generating speech coding parameters of an erased frame in a bitstream-based front end of a speech recognition system, the method comprising the steps of: detecting an erased frame; computing the probability of a correct observation sequence from the group O=(O 0 ,O m ), where the probability is defined as: P ⁡ ( O c | λ ) = ∑ q 1 , … , q N ⁢ π q ⁢ ⁢ 1 ⁢ b q ⁢ ⁢ 1 ⁡ ( o 1 ) ⁢ a q ⁢ ⁢ 1 ⁢ q ⁢ ⁢ 2 ⁢ b q ⁢ ⁢ 2 ⁡ ( o 2 ) ⁢ ⁢ … ⁢ ⁢ a q ⁢ ⁢ 1 - Nq ⁢ ⁢ 1 ⁢ a q ⁢ ⁢ 1 ⁢ q ⁢ ⁢ 1 + n ⁢ b q ⁢ ⁢ 1 + 1 ⁡ ( o l + Γ ) ⁢ ⁢ … ⁢ ⁢ a qN - 1 ⁢ qN ⁢ b qN ⁡ ( o N ) deleting an observation vector of the erased frame from the observation sequence; and decoding the observation sequence with a speech decoder using a standard hidden Markov model process.