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Based on a survey on the technical challenges to the future radio access network beyond LTA-Advanced, which should offer very high average areal throughput to support a vast amount of data traffic and user density with energy-efficient operation, we discuss the potential techniques and propose an overall framework.
Future pervasive communication systems requirements for highly performing, flexibly deployable and cost/energy-efficient services and applications are expected to revolutionize the way we design, optimize and use wireless networks. From a cellular perspective, the emphasis is placed on achieving ubiquitous and reliable real-time data communications at cell-edge, as articulated in ITU's IMT-Advanced...
In wireless multimedia communications, optimizing the quality of user experience is a major design goal, which is often quantified by the end-to-end distortion between the actual multimedia source at the encoder and its reconstructed version at the decoder. Joint source-channel coding (JSCC) techniques aim to optimize codec and radio system parameters in order to minimize end-to-end distortion and...
We consider the design of a multi-input multi-output (MIMO) transmission system equipped with distributed, single-antenna amplify-and-forward relays. In particular, we consider how to optimize the complex forwarding coefficients of the relays to maximize the system capacity. Existing studies on MIMO relay network designs mostly concentrate on the case of single relay with multiple antennas, whose...
In this paper, an efficient Multiple-input multiple-output (MIMO) detection scheme with low complexity is proposed. The proposed scheme has a feature of combined a QRD-M, which is the M-algorithm combined with QR decomposition, with a complex lattice reduction (LR)-aided detection scheme. For the first T stages, the QRD-M detection is executed. And then, the complex LR-aided detection is executed...
Amplify-and-forward (AF) is one of the most popular and simple approaches to transmit information over a cooperative multi-input multi-output (MIMO) relay channel. In this paper, we propose three novel power allocation methods for the downlink of cooperative multi-user MIMO AF system, which are designed to maximize the weighted sum-rate (WSR) of the cooperative system, by considering two different...
Instead of using eigen-beamforming approach to increase capacity gain, an optimal weight scheme is employed in the closed-loop multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (MIMO-OFDM) wireless system design. In particular, this scheme provides an uplink scale weight vector pre-weighting space-time block code (STBC) signals at each transmit sub-carrier in accordance...
In this paper, we propose an antenna selection algorithm for down link MIMO SDMA OFDM system. For each user, the data rate corresponding to each transmit antenna is maximized using the optimal bit loading algorithm. A data rate matrix is constructed and used for the antenna selection algorithm assuming the base station (BS) knows the signal-to-noise ratio on all antenna-user pairs of all sub-carriers...
In wireless dual-hop decode-and-forward (DF) relaying networks, multiple relay stations (RS) and users construct a multiple-in-multiple-out (MIMO) broadcast channel (BC). Due to unpredictable decoding failure, scheduling the transmission for the decode-and-forward broadcast channel (DFBC) should depend on not only channel qualities but also the availability of errorless data at individual RSs. Based...
Centralized algorithms for weighted sum rate (WSR) maximization for the K-user frequency-flat MIMO Interference Channel (MIMO IFC) with full channel state information (CSI) are considered. Maximization of WSR is desirable since it allows the system to cover all the rate tuples on the rate region boundary for a given MIMO IFC. First, we propose an iterative algorithm to design optimal linear transmitters...
In order to overcome the indoor coverage problem for residential users, the deployment of home base stations (also referred as home-eNB) has been regarded as a promising solution. However, the unpredictable deployment pattern of home-eNBs makes centralized network planning impractical and requires distributed spectrum planning to achieve effective interference management. In this paper, by enabling...
It has been recognized that a primary method of further enhancing the spectral efficiency of LTE Release-8 is to improve support for multi-user (MU) MIMO transmission in the downlink in an efficient manner. This paper investigates the performance improvements due to the enhanced support of single-cell MU-MIMO within the framework of LTE evolution (specifically LTE Release-9 and Release-10 also known...
Multiuser interference (MUI) and co-space interference (CSI) are two challenging issues in design of multicarrier code-division multiple-access (MC-CDMA) systems when multiple antennas are used at both the transmitter and receiver sides (MIMO transmission). On the other hand, in cognitive radio (CR) system, the secondary users that use MC-MCDA technique must deactivate the subcarriers used by the...
This paper addresses multiple access in MIMO wireless networks. It compares two distributed interference alignment techniques, in space and in frequency, that both aim at removing interferences through orthogonalization. The theoretical advantages and drawbacks of each technique are highlighted. Then, the multiplexing gain and the computational complexity are analytically evaluated. It is shown that...
In this paper, performance of Transmit Antenna Selection / Maximal Ratio Combining (TAS / MRC) in two hop Amplify-and-Forward (AF) relay system is analyzed over frequency non-selective and slowly Rayleigh fading channel. In the system, all nodes are equipped with multiple antennas; TAS is employed at the source and relay for transmission, MRC is employed at the relay and destination for reception...
A novel 3D cluster-based double-directional MIMO channel model with consideration of polarization is proposed and the modeling process is described in detail. The spatial channel model (SCM) proposed by 3GPP (3rd Generation Partnership Project) is retrieved and compared with the new model. Based on the new model, capacity and spatial correlation of the co-located dual- and triple-polarized MIMO systems...
We analyze the performance of amplify-and-forward (AF) multiple-input multiple-output (MIMO) cooperative networks over independent but not identically distributed Nakagami-m fading channels. Specifically, we consider an AF MIMO relay network where the source deploys the transmit antenna selection scheme to communicate with the destination through the help of a relay. We derive analytical expressions...
A framework of joint antenna selection and source coding strategy for scalable video transmission over wireless systems was proposed. Each layer of a bit-stream could be switched among multiple transmit antennas in order to achieve unequal error protection (UEP) for prioritized video layered bit-streams. At first wavelet-based 3D ESCOT codec generates layered bit streams that need prioritized delivery...
The effective method of two-way relaying for TDD (Time Division Duplex) wireless systems is described. In a traditional two-way relaying without network coding four time slots are needed in the TDD mode to exchange data blocks between two stations, e.g. mobile (MS) and base (BS) stations via a relay station (RS). In the proposed solution the number of slots is reduced to two only - the multiple access...
This paper aims at investigating the required feedback to achieve the Degrees of freedom (DoF) of X channel. Accordingly, a fixed precoding approach is proposed and is argued can achieve the DoF of such channel, assuming the channel state information is partially available at each transmitter through a feedback mechanism. This is achieved through using the notion of ergodic interference alignment...
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