Patent ID: 7428277

Claim:
A method of determining an acquisition indicator bit AI s at a receiver in a communication system, the method comprising: receiving multiplexed acquisition bits y=B×AI+n, where B is the signature matrix known at both base station and the receiver, AI is all the acquisition indicator bits and n represents noise; calculating an estimated value of the AI bit of interest AÎ MMSE (s) as a function of ∑ j ⁢ B T ⁡ ( s , j ) × y ⁡ ( j ) , where B T (s,.) is the s-th row vector of the transposed matrix B T for acquisition indicator bit AI s ; and setting the acquisition indicator bit AI s as follows: AI s =−1, if AÎ MMSE ( s )< R AI s =0, if R≦AÎ MMSE ( s )< U AI s =1, if AÎ MMSE ( s )≧ U where R and U are decision thresholds, wherein the estimated value AÎ MMSE (S) is calculated by A ⁢ I ^ MMSE ⁡ ( s ) = 1 ( J + σ ^ 2 ) ⁢ ∑ 0 J - 1 ⁢ B T ⁡ ( s , j ) × y ⁡ ( j ) , wherein {circumflex over (σ)} 2 represents estimated noise variance at the receiver, and J is an integer greater than or equal to 0.