Precoder Design With Incomplete Feedback for Joint Transmission
Journal article, 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

Author

Tilak Rajesh Lakshmana

Chalmers, Signals and Systems, Communication and Antenna Systems, Communication Systems

Antti Tölli

Centre for Wireless Communications Finland

Rahul Devassy

Chalmers, Signals and Systems, Communication and Antenna Systems, Communication Systems

Tommy Svensson

Chalmers, Signals and Systems, Communication and Antenna Systems, Communication Systems

IEEE Transactions on Wireless Communications

1536-1276 (ISSN)

Vol. 15 3 1923-1936

Mobile and wireless communications Enablers for Twenty-twenty (2020) Information Society (METIS)

European Commission (FP7), 2012-11-01 -- 2015-04-30.

Areas of Advance

Information and Communication Technology

Subject Categories

Telecommunications

Communication Systems

Infrastructure

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1109/TWC.2015.2497223

More information

Created

10/7/2017