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From a practical point of view, fast Maximum Likelihood Decoding (MLD) and low Peak-to-Average-Power- Ratio (PAPR) are two important design criteria for Space-Time Block Codes (STBCs). The use of the principle of conditional detection allows for having high-rate STBCs while keeping the complexity of detection at a reasonable level. Recently, we proposed a structure for a STBC with fast MLD having...
An extension to decomposition based transmit beamforming is proposed for multiple input multiple output (MIMO) multiuser systems. In contrast to conventional beamforming which is constrained towards orthogonalizing the subchannels of the different users to yield groups of correlated antennas that belong to only one user, a more flexible orthogonalization approach is proposed which is targeted directly...
In this paper, we proposes the pro-active beamforming (BF) protocol realized in media access control (MAC) layer following IEEE 802.15.3c criteria for millimeter-wave 60GHz wireless personal area networks (60GHz WPANs). The pro-active BF may be used when the piconet controller (PNC) is the source of data to one or multiple devices (DEVs). It allows multiple DEVs to train their own receiver antennas...
The keyhole phenomenon, i.e., uncorrelated but rank-deficient fading, can lead to significant performance degradations in multiple-input multiple-output (MIMO) systems and has to be carefully taken into account for system design. In this paper, considering the practically important case of two transmit and an arbitrary number of receive antennas, we provide a simple closed-form expression for the...
This paper investigates the cooperative timing acquisition (CTA) for distributed antenna systems (DAS). As a preliminary study, the path loss and additive white Gaussian noise (AWGN) channel are considered without assuming multipath fading and shadowing. In the DAS coverage region, two remote antennas (RA) are assumed at base station (BS) for receiving the signal transmitted from the mobile station...
With the ever increasing interest in multiple-input multiple-output (MIMO) cognitive radio (CR) systems, reducing the costs associated with RF-chains at the radio front end becomes a very important factor. In this paper, we propose two solutions to the problem of joint transmit-receive antenna selection with the objective of maximizing data rates and satisfying interference constraints at the primary...
In this paper we propose an improved multiple-input multiple-output (MIMO) polynomial cancellation coding (PCC) orthogonal frequency division multiplexing (OFDM) system. In this improved system, PCC OFDM symbols are transmitted from different antennae with different time offsets. At the receiver these symbols are demodulated using each of those time offsets. Time offsets substantially reduce the power...
In this paper, we consider a robust design of MIMO-relay precoder and receive filter for the destination nodes in a non-regenerative multiple-input multiple-output (MIMO) relay network. The network consists of multiple source-destination node pairs assisted by a single MIMO-relay node. The source and destination nodes are single antenna nodes, whereas the MIMO-relay node has multiple transmit and...
This paper is on interference cancellation (IC) schemes for a two-user relay network where users are allowed to communicate simultaneously. The considered networks have one double-antenna half-duplex relay, single-antenna receiver but three scenarios on both users: single-antenna, double-antenna, and four-antenna. We apply the IC scheme, which was originally proposed for multi-antenna multi-user direct...
This paper presents blind channel estimation for Alamouti coding operating in time-correlated Rayleigh channels. A decision algorithm first obtains primary data estimates of the transmitted symbols based on the constrained linear minimum mean square error criterion, and these are applied to subsequent optimal minimum mean square error channel estimation. Performance is evaluated by simulation under...
In full duplex amplify-and-forward (FD-AF) relays, self-interference from the transmit side causes a major problem hindering its commercial spread. To alleviate the front-end saturation problem, we propose a spatial self-interference nullification method employing extra transmit antennas in FD-AF multiple-input-multiple-output (MIMO) relay systems, and analyze characteristics of the proposed system...
A dynamic narrowband on-body area communications scenario is characterized with respect to link margin as a difference between system operating point, in terms of receive power, and receiver sensitivity. The characterization is based on an extensive measurement campaign near the 900 MHz ISM bands, with a number of different human subjects moving at a range of speeds in an indoor-office scenario. Key...
A novel combination of block spread orthogonal frequency division multiple access (BS-OFDMA) with space-time coded multiple input multiple output (STC MIMO) scheme is proposed for broadband wireless access uplink transmission. Using complex exponential spreading sequences, the block spreading technique can efficiently generate precoded OFDMA signal to exploit frequency diversity. An Alamouti STC MIMO...
Recent work has shown that mesh networks based on short-range outdoor millimeter (mm) wave links in the unlicensed 60 GHz band are a promising approach to providing an easily deployable broadband infrastructure. In this paper, we investigate the robustness of such links, focusing in particular on the effect of multipath fading resulting from reflections from the ground and building walls for a lamppost...
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