MIMO techniques in WiMAX and LTE: a feature overview

IEEE Communications Magazine (Impact Factor: 3.66). 06/2010; DOI: 10.1109/MCOM.2010.5458368
Source: IEEE Xplore

ABSTRACT IEEE 802.16m and 3GPP LTE-Advanced are the two evolving standards targeting 4G wireless systems. In both standards, multiple-input multiple-output antenna technologies play an essential role in meeting the 4G requirements. The application of MIMO technologies is one of the most crucial distinctions between 3G and 4G. It not only enhances the conventional point-to-point link, but also enables new types of links such as downlink multiuser MIMO. A large family of MIMO techniques has been developed for various links and with various amounts of available channel state information in both IEEE 802.16e/m and 3GPP LTE/LTE-Advanced. In this article we provide a survey of the MIMO techniques in the two standards. The MIMO features of the two are compared, and the engineering considerations are depicted.

1 Bookmark
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Support of femtocells is an integral part of the Long Term Evolution - Advanced (LTE-A) system and a key enabler for its wide adoption in a broad scale. Femtocells are short-range, low-power and low-cost cellular stations which are installed by the consumers in an unplanned manner. Even though current literature includes various studies towards understanding the main challenges of interference management in the presence of femtocells, little light has been shed on the open issues of mobility management (MM) in the two-tier macrocell-femtocell network. In this paper, we provide a comprehensive discussion on the key aspects and research challenges of MM support in the presence of femtocells, with the emphasis given on the phases of a) cell identification, b) access control, c) cell search, d) cell selection/reselection, e) handover (HO) decision, and f) HO execution. A detailed overview of the respective MM procedures in the LTE-A system is also provided to better comprehend the solutions and open issues posed in real-life systems. Based on the discussion for the HO decision phase, we subsequently survey and classify existing HO decision algorithms for the two-tier macrocell-femtocell network, depending on the primary HO decision criterion used. For each class, we overview up to three representative algorithms and provide detailed flowcharts to describe their fundamental operation. A comparative summary of the main decision parameters and key features of selected HO decision algorithms concludes this work, providing insights for future algorithmic design and standardization activities.
    IEEE Communications Surveys &amp Tutorials 01/2014; 16(1):64-91. · 4.82 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We model and analyze multiple-input multiple-output heterogeneous cellular networks (MIMO HetNets) with K classes or tiers of base stations (BSs), which may differ in terms of transmit power, deployment density, number of transmit antennas, number of users served, transmission scheme, and path loss exponent. We show that the cell selection rules in MIMO HetNets may differ significantly from the single-antenna HetNets due to the possible differences in multi-antenna transmission schemes across tiers. While it is challenging to derive exact cell selection rules even for maximizing signal-to-interference-plus-noise-ratio (SINR) at the receiver, our analysis concretely demonstrates that adding a fixed tier-dependent bias in the received power while doing cell selection leads to a near optimal performance both for downlink coverage and rate. Assuming arbitrary selection bias for each tier, simple expressions for these performance metrics are derived. For coverage maximization, the required selection bias for each tier is given in closed form. Due to this connection with biasing, MIMO HetNets may balance load more naturally in certain regimes compared to single-antenna HetNets, where an artificial selection bias is often needed.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we present a differential codebook design by modifying the Grassmannian codebook for a single-cell multiuser (MU) multiple-input single-output (MISO) system operating under spatially and temporally correlated channels. The differential codebook design involves scaling and rotation methods that help a codebook to track the slow varying channel. We propose an adaptive scaling technique that improves the performance of the system in correlated channels without any additional feedback information. Monte Carlo simulations show that the proposed differential codebook reduces quantization errors and improves sum-rate performance as compared to other differential codebooks designed for spatially and temporally correlated MISO channels.
    Proc. IEEE International Conference on Communications (ICC); 06/2013

Full-text (4 Sources)

Available from
May 26, 2014