Energy optimization of CDMA transceivers using successive interference cancellation

In broadband code division multiple access (CDMA) communications, it has been shown that receivers based on successive interference cancellation (SIC) provide an effective reduction of multiuser access interference at an affordable complexity. We propose an optimization of CDMA systems by using power control and a suitable order of user detection at the SIC receiver. The aim is to minimize the total transmit power, while ensuring equal signal to noise plus interference ratio (SNIR) at the detection point for all users. Performance evaluation in an uplink multiuser scenario for the UMTS-TDD standard shows that the proposed algorithm provides energy saving of up to 7 dB in the absence of scrambling and up to 3 dB in the presence of scrambling, with respect to existing architectures based on SIC.