Patent ID: 7643589

Claim:
A method executed in a receiver that includes a first antenna that receives a signal expressible as a vector of signals r 1 , a second antenna that receives a signal expressible as a vector of signals r 2 where signal vectors r 1 and r 2 contain signals transmitted by a first transmitter and signals transmitted by a second transmitter, H 1 is a matrix of transfer coefficients between said first transmitter and said first antenna, H 2 is a matrix of transfer coefficients between said first transmitter and said second antenna, G 1 is a matrix of transfer coefficients between said second transmitter and said first antenna, G 2 is a matrix of transfer coefficients between said second transmitter and said second antenna, and Γ is the signal to noise ratio, comprising the steps of: (1) executing a module for developing an estimate ŝ i of signal s i , i=1, 2, transmitted by said second transmitter by (a) computing F i (s)=∥x 1,i −G 1 ·s∥ 2 +∥x 2,i −G 2 ·s∥ 2 , where x 1,i =r 1 −H 1 ·ĉ i , x 2,i =r 2 −H 2 ·ĉ i , and ĉ i is estimate of symbol c i sent by said first transmitter, (b) choosing ŝ i according to s ^ t = arg ⁢ ⁢ ⁢ min s ∈ S ⁢ ( F ⁡ ( s ) ) , and (c) setting Δ s,i to F i (s), (2) executing a module for developing an estimate ĉ i of signal c i , i=1, 2, transmitted by said first transmitter by (a) computing F i (c)=∥y 1,i −G 1 ·c∥ 2 +∥y 2,i −G 2 ·c∥ 2 , where y 1,i =r 1 −H 1 ·ŝ i , y 2,i =r 2 −H 2 ·ŝ i , and ŝ i is estimate of symbol s i sent by said second transmitter, (b) choosing ĉ i according to c ^ t = arg ⁢ ⁢ ⁢ min c ∈ C ⁢ ( F ⁡ ( c ) ) , and (c) setting Δ c,i to F i (c), (3) choose pair (ĉ o ,ŝ 0 ) if (Δ c,0 +Δ s,0 )<(Δ c,1 +Δ s,1 ) and pair (ĉ 1 ,ŝ 1 ) otherwise; and (4) repeat steps (1)-(3) at one more time.