Robustness of the reference symbol assisted multistage successive interference cancelling receiver with imperfect parameter estimates

Abstract

This paper investigates the sensitivity to system imperfections of a multistage successive interference cancelling receiver with reference symbol assisted channel estimation. In particular, performance losses due to nonideal transmitter power amplifier gating, imperfect power control and synchronization errors in the RAKE receiver are determined. The results show that for path loss exponent of 4. Imperfect amplifier gating causes a relatively minor decrease in the system capacity while no such effect is observed for path loss exponents of 2 and 3. As expected, relaxing of power control has a similar capacity reducing effect. In spite of these two effects the resultant capacity is still significantly higher than that with the conventional matched filter receiver. Chip synchronization errors of the order to be expected in a properly designed CDMA system also have only minimal influence on performance. Therefore, conventional synchronization algorithms should perform adequately with successive interference cancelling receivers considered in the paper.