Equal BER Performance in Linear Successive Interference Cancellation for CDMA Systems

In this contribution we calculate the received power distribution required to obtain equal BER performance for all links in a CDMA system employing a linear successive interference cancellation (SIC) receiver at the base station for an AWGN channel. We show that the variance of the decision statistic of the linear SIC receiver can be formulated in a non-recursive manner which alows calculation of the power profile necessary to obtain equal signal-to-noise-plus-interference ratios for all received signals when cancellation order is determined based on average power. When equal BER performance is required, this formulation allows capacity limits to be determined for a required SINR or an SINR limitation to be calculated for a given capacity. We also show that the power profiles required are significantly larger than those obtained when perfect cancellation is assumed, highlighting the inadequacy of such an assumption.