DFE convergence for interference cancellation in spread spectrum multiple access systems

A fractionally spaced decision feedback equalizer (DFE) is proposed for code division multiple access (CDMA) in an interference-dominated environment. This system assumes no knowledge of the interferers' spreading codes. The calculation of optimum receiver taps shows good improvement in the capacity of the proposed system over others. The DFE receiver is simulated in a multiuser multipath environment. Performance results show the expected convergence of the DFE, with and without knowledge of the desired user's spreading code. Results also show the effect of sudden birth and death of interferers in the system. The bit error rate of the simulated DFE system is presented.