Perturbation study on MOE-based multiuser detection

The minimum output energy (MOE) receiver has been developed for multiuser detection. Its performance has been shown to be very close to the minimum mean square error (MMSE) receiver at high signal to noise ratio (SNR). However due to additive noise, the constraint vector required to construct the MOE receiver becomes a biased estimated channel vector. Thus the receiver is also perturbed. In addition to the noise, other factors affect the receiver´s performance as well. Effects from such factors as finite number of data samples and channel order overestimation are studied in this paper based on perturbation theory.