A Real-Time DSP-based Iterative (Turbo) Multiuser Detection Employing Interference Cancellor-MMSE

In this paper, we investigate the implementation of an efficient low complexity iterative detector (namely IC-MMSE), for coded direct sequence code division multiple access (DS-CDMA) system, under fixed-point data representation and computation constraint. TMS320C6416 TI´s fixed point DSP, part of the C6416 DSK platrform, is utilized. Real time simulations are made possible by using real time data exchange (RTDX) technology. For performance evaluation extrinsic information transfer (EXIT) chart analysis is used. EXIT charts reveal that fixed point implementation is feasible at possibly no performance degradation. Based on the measured number of cycles of different constituent sub-functions of the IC-MMSE receiver, a data transmission rate of up to 186 Kb/s can be reached for a 5-users load and processing gain of 7 in an AWGN channel