environment having awgn and mui is calculated by p c 1 2 ue89e exp ue8a0 r c and r c e b u00b7 a 2 4 ue89e p el u00b7 2 ue89e k c 3 ue89e n ue89e e b u00b7 a 2 2 ue89e k c 1 3 ue89e n ue89e e b u00b7 a 2 u00b7 2 2 n 0 2 12 4 improvement of system performance with serially connected adaptive array antenna and interference canceller the adaptive array antenna 21 which is serially connected to interference canceller 22 forms a beam in the direction of a desired signal on the basis of a weighting value calculated in the adaptive receive processor which maximizes the reception gain of the desired signal antenna 21 also provides a null to an mui signal received from a different direction than that of the desired signal in order to minimize the reception gain of the mui signal thus the mui signal is eliminated here the remaining mui signal of antenna 21 and an mui component received at the same angle as that of the desired signal are cancelled by relying on correlation of the received signal by interference canceller 22 an error probability equation for a ds cdma dpsk system using the serially connected adaptive array antenna 21 and interference canceller 22 in an environment having awgn and mui is.