Advanced CDMA scheme based on interference cancellation

The pseudorandom noise (PN) code is used for a CDMA scheme to spread the spectrum of user data. When the number of users increases, the signals of other users cause interference noises. The fundamental factor of the interference is dependent on the cross-correlation characteristics of the PN code. A scheme for improving the capacity is proposed, based on interference cancellation. The scheme is evaluated on the characteristics of bit-error-rate (BER) vs number of simultaneous users by computer simulations. It is found that around 60 users are available per cell by the proposed method without error correction and voice activity control. Around eight times the capacity of the conventional correlation scheme is achieved. The configuration of the personal station is effectively reduced in size and cost, because the complicated voice activity control is not necessary, and the IC is installed in the base station