Implementing the bootstrap algorithm to multi-shot matched filtering, multiuser detection

CDMA proves to be an attractive method for multiuser communication due to its potential capacity increase and anti-multipath fading capability. However, its performance is limited by the existence of multiuser interference energy (MI), which results in the so called near-far problem. To reduce the MI effect, different decorrelating structures for multiuser detection have been proposed. For the asynchronous case, the “one-shot decorrelator” was proposed, based on inversion of the partial correlation matrix, which may however be singular. As an alternative, the so-called “multi-shot decorrelator”, which does not suffer from the aforementioned singularities, was also suggested. However, both detectors, based on inversion of some matrix, are not robust to errors in the users´ relative delays. The application of the adaptive “bootstrap algorithm” with the one-shot structure proved to easily handle variation in delay estimates and outperform the decorrelating detector. We propose and compare a bootstrap algorithm suitable for the multi-shot matched filtering, multiuser detector in a multipath environment, examine its performance, and compare it to that of other detectors