Publications in Scientific Journals:
J. Maurer, J. Jaldén, D. Seethaler, G. Matz:
"Vector Perturbation Precoding Revisited";
IEEE Transactions on Signal Processing,
We consider the downlink of a multiuser system with multiple antennas at the base station. Vector perturbation (VP) precoding is a promising variant of transmit-side channel inver- sion allowing the users to detect their data in a simple, noncoopera- tive manner. VP precoding has so far been developed and analyzed under the assumptions that the transmitter has perfect channel state information (CSI) and that the receivers know perfectly a channel-dependent transmit power normalization factor and have infinite dynamic range. We demonstrate that the violation of any of these idealizing assumptions degrades the performance of VP sig- nificantly and almost always results in an error floor. Motivated by this observation, we propose a novel scheme which we term transmit outage precoding (TOP). With TOP, the transmitter uses a prearranged power scaling known by the receivers and refrains from transmitting when channel conditions are poor. We further show how to augment TOP and conventional VP to deal with a finite dynamic range at the receiver. The performance of the proposed schemes under various levels of transmit CSI is studied in terms of a theoretical diversity analysis and illustrated by numer- ical results.
Electronic version of the publication:
Created from the Publication Database of the Vienna University of Technology.