Precoder Design With Incomplete Feedback for Joint Transmission
Artikel i vetenskaplig tidskrift, 2016

A centralized coordinated multipoint downlink joint transmission in a frequency division duplex system requires channel state information (CSI) to be fed back from the cell-edge users to their serving BS, and aggregated at the central coordination node for precoding, so that interference can be mitigated. The control signals comprising of CSI and the precoding weights can easily overwhelm the backhaul resources. Relative thresholding has been proposed to alleviate the burden; however, this is at the cost of reduction in throughput. In this paper, we propose utilizing the long term channel statistics comprising of pathloss and shadow fading in the precoder design to model the statistical interference for the unknown CSI. In this regard, a successive second order cone programming (SSOCP) based precoder for maximizing the weighted sum rate is proposed. The accuracy of the solution obtained is bounded with the branch and bound technique. An alternative optimization framework via weighted mean square error minimization is also derived. Both these approaches provide an efficient solution close to the optimal, and also achieve efficient backhauling, in a sense that the precoding weights are generated only for the active links. For comparison, a stochastic approach based on particle swarm optimization is also considered.

branch and bound

MSE

limited backhauling/feedback

precoding

CoMP

SSOCP

weighted sum rate maximization

Författare

Tilak Rajesh Lakshmana

Signaler och system, Kommunikationssystem, informationsteori och antenner, Kommunikationssystem

Antti Tölli

Centre for Wireless Communications Finland

Rahul Devassy

Signaler och system, Kommunikationssystem, informationsteori och antenner, Kommunikationssystem

Tommy Svensson

Signaler och system, Kommunikationssystem, informationsteori och antenner, Kommunikationssystem

IEEE Transactions on Wireless Communications

1536-1276 (ISSN)

Vol. 15 1923-1936

Styrkeområden

Informations- och kommunikationsteknik

Ämneskategorier

Telekommunikation

Kommunikationssystem

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1109/TWC.2015.2497223