Weighted Sum-rate Maximization for Multi-user Mimo-OFDM Downlink with ZF-DPC Methods

P. Krishna, T. Anil Kumar, K. Kishan Rao

2014

Abstract

Multi -user MIMO techniques were born due to the urge of high data rates and spectral efficiency in 4G systems. For scenarios with a large number of users to be served in one cell, high capacity gains can be achieved by transmitting independent data streams to different users sharing the same time -frequency resources through the use of MIMO precoding. Linear precoding is employed in MU-MIMO communication system to improve the system capacity and to minimize the receiver complexity. The previous works on optimization algorithm to design a linear precoder to maximize the system capacity is assumed to have perfect channel state information (CSI) at the base station (BS).However the CSI available at the BS is imperfect due to channel estimation errors. With enough channel state information (CSI) at the transmitter, MIMO precoding allows to increase multi-user diversity gain. However, without a correct precoding vector selection, the interference between users can seriously degrade the overall network data rate. In a close-loop configuration, the base station (BS) receives from each user the preferred precoding vector and modulation and coding scheme (MCS).To achieve the highest multi -user diversity gains and avoid users interference, the BS needs to recalculate the precoding vector and MCS for each user. Weighted sum rate maximization is also considered, and qualification of throughput difference between two strategies is performed. In this process, it is shown that allocating the user powers in direct proportional to user weights asymptotically maximizes weight sum rate. The goal of this paper is to investigate the performance and complexity of state -of-the - art methods for calculation of precoding vectors such as zero –forcing (ZF) or mean square error (MMSE) and Dirty paper Coding(DPC).

References

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Paper Citation


in Harvard Style

Krishna P., Anil Kumar T. and Kishan Rao K. (2014). Weighted Sum-rate Maximization for Multi-user Mimo-OFDM Downlink with ZF-DPC Methods . In Doctoral Consortium - DCPECCS, (PECCS 2014) ISBN Not Available, pages 14-17. DOI: 10.5220/0004876700140017


in Bibtex Style

@conference{dcpeccs14,
author={P. Krishna and T. Anil Kumar and K. Kishan Rao},
title={Weighted Sum-rate Maximization for Multi-user Mimo-OFDM Downlink with ZF-DPC Methods},
booktitle={Doctoral Consortium - DCPECCS, (PECCS 2014)},
year={2014},
pages={14-17},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0004876700140017},
isbn={Not Available},
}


in EndNote Style

TY - CONF
JO - Doctoral Consortium - DCPECCS, (PECCS 2014)
TI - Weighted Sum-rate Maximization for Multi-user Mimo-OFDM Downlink with ZF-DPC Methods
SN - Not Available
AU - Krishna P.
AU - Anil Kumar T.
AU - Kishan Rao K.
PY - 2014
SP - 14
EP - 17
DO - 10.5220/0004876700140017