Patent ID: 7724809

Claim:
A joint detection-decoding receiver of a DS-CDMA system, the receiver comprising: a matched filter for dividing a plurality of channel coded symbols of a plurality of users according to each of the plurality of users to generate a matched filter output; and a multistage parallel interference canceller for repeatedly carrying out a symbol estimation for each of the plurality of users using the matched filter output and a symbol removal of other users using a correlation matrix to reduce a multiple access interference, wherein the multistage parallel interference canceller estimates a partial code word corresponding to a branch as a symbol estimation using a state sequence, and wherein the multistage parallel interference canceller estimates the partial code using an equation d ^ k ( t ) = arg ⁢ ⁢ max s t , s t - 1 ∈ S ⁢ [ log ⁢ ⁢ Pr ⁡ ( α t - 1 ⁡ ( s t - 1 ) ⁢ γ ⁡ ( s t - 1 , s t ) ) ] , wherein α t (s t ) is defined as α t ⁡ ( s t ) = ∑ s t - 1 ⁢ α t - 1 ⁡ ( s t - 1 ) ⁢ γ t ⁡ ( s t - 1 , s t ) , α 0 (0)=1, and α 0 (i)=0 for i≠0, and γ t (s t-1 s t ) is defined as γ t (s t-1 , s t )=Pr{y k (t) |d k (t) }·Pr{S k (t) =s t =|S k (t-1) =s t-1 }, where S t is a state at a time t, and S t-1 is a state at a time t-1.