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The following topics are dealt with: neural networks; equalisation; mobile and cellular communications; optical communications; data security; human factors in communications; coding and modulation; optical networks; database and optimisation; time-frequency analysis; computer vision and recognition; audio and speech processing; wireless networks; watermarking; digital filters; network coding and...
We consider soft MIMO detection for the case of block fading. That is, the transmitted codeword spans over several independent channel realizations and several instances of the detection problem must be solved for each such realization. We develop methods that adaptively allocate the computational resources to the detection problems of each channel realization, under a total per-codeword complexity...
In this paper, a new opportunistic feedback and user selection protocol is proposed for the multiple antenna downlink. The proposed scheme uses the structure of zero-forcing dirty paper coding (DPC) at the transmitter and selects users using a contention-based feedback channel. The user selection procedure is divided into stages and within each stage, a user is selected for one spatial channel (defined...
We propose a novel communication scheme that combines rateless transmission and multilevel coding (MLC). The scheme is able to attain a throughput that is equal to the constellation-constrained channel capacity. It is particularly useful in cases where the celebrated bit-interleaved coded modulation (BICM) would leave significant gaps to the channel capacity and therefore, MLC is necessary for efficient...
We consider the problem of broadcasting a common message and two individual messages to two users on a product channel of two reversely degraded Gaussian multiple-input multiple-output (MIMO) broadcast channels. Though El Gamal provided a single letter characterization for the general discrete memoryless problem in 1980, this characterization in fact does not include a channel cost constraint, and...
We study motion compensated fine granular scalable (MC-FGS) video transmission over multi-input multi-output (MIMO) wireless channels, where leaky and partial prediction schemes are applied in the enhancement layer of MC-FGS to exploit the tradeoff between error propagation and coding efficiency. For reliable transmission, we propose unequal error protection (UEP) by considering a tradeoff between...
In this paper we study the data-error performance of Linear Dispersion (LD) codes under spatial correlated multiple-input multiple-output (MIMO) channels. We propose a new precoding algorithm for LD codes by minimizing the pairwise error probability (PEP). This precoding can totally remove the spatial correlation existing in the transmitter. Particularly, the precoding process can be integrated into...
We present a multilayer space-time-frequency (STF) coding scheme for wideband multiple-input multiple-output (MIMO) systems employing orthogonal frequency-division multiplexing (OFDM). With multiple receive antennas, we employ an iterative demodulator consisting of a low-complexity multilayer detector and a simple soft combiner. The system performance is optimized by efficient power allocation among...
We propose a framework for multicasting layers of scalable video over a broadcast channel to multiple users simultaneously. The framework ensures that all users receive the content, but at differentiated levels of quality depending on channel conditions. A coding scheme well-suited to this purpose is Scalable Video Coding (SVC). In particular, we employ medium-grain scalability (MGS), which allows...
Transmitter preceding is a crucial technique for harnessing the potential of multiple-input multiple-output (MIMO) fading channels. In many practical wireless systems, a limited amount of feedback from the receiver is available at the transmitter, which can be used to direct the choice of the precoder from a codebook to match the channel state. Assuming noiseless, limited-rate feedback, this work...
This paper studies the computation of postprocessing signal-to-interference plus noise ratio (SINR) for maximum likelihood detector (MLD) in multiple-input and multiple output (MIMO)-orthogonal frequency division multiplexing (OFDM) spatial multiplexing systems. We derive an effective post-MLD SINR for each spatial stream, which is computed as post minimum mean-squared error (MMSE) SINR plus gain...
This paper presents a novel multi-functional MultipleInput Multiple-Output (MIMO) scheme that combines the benefits of the Vertical Bell Labs Layered Space-Time (V-BLAST) scheme, of SpaceTime Codes (STC) as well as of beamforming. To further enhance the attainable system performance and to maximise the coding advantage of the proposed transmission scheme, the system is also combined with multi-dimensional...
We consider the Gaussian multiple-input multiple-output (MIMO) multi-receiver wiretap channel, and derive the secrecy capacity region of this channel for the most general case. We first prove the secrecy capacity region of the degraded MIMO channel, in which all receivers have the same number of antennas, and the noise covariance matrices exhibit a positive semi-definite order. We then generalize...
This paper proposes a bit-interleaved coded transmission with multilevel modulation for multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems. In the proposed system, multiple layers are encoded and interleaved together, using one encoder and one interleaver, and then mapped by hierarchical symbol mapping. A corresponding receiver structure is presented, where...
This paper proposes a cooperative multiple-input multiple-output (MIMO) architecture to transmit the video reliably. By exploring the configurable resources of the scalable video and the coded MIMO system, we further propose a novel joint source-channel coding (JSCC) framework with optimal tradeoff among diversity, multiplexing and coding gains. In this framework, the concatenated low-density parity-check...
In this paper we consider efficient and low complexity scheduling algorithms for multiuser multiple-input multiple-output (MIMO) systems. The optimal user scheduling involves an exhaustive search, which becomes very complex for realistic numbers of users and transmit antennas. Among various suboptimal but low complexity algorithms, greedy algorithms with heuristic scheduling metrics have been shown...
In this paper, an Irregular Distributed Space-Time (Ir-DST) coding scheme is studied in the context of a twin-relay aided network in which the successive relaying protocol is employed. A tight upperbound of the successive relaying aided network's capacity is given. The distributed codes at the source and relays are jointly designed with the aid of Extrinsic Information Transfer (EXIT) charts for the...
Wireless communication using multiple-input multiple-output (MIMO) systems improves throughput and enhances reliability for a given total transmit power. Achieving a higher data rate in MIMO systems requires utilizing an effective space-time coding and modulation scheme. The appropriate algorithm to use for a system will depend on parameters such as the number of transmit/receive antennas, target...
To overcome the adverse effects of wireless channel, cooperative communications is the practical implementation of Multiple-Input-Multiple-Output (MIMO) concept in size constraint nodes. To exploit the benefits of cooperative transmission properly, we use the block-Markov encoding. Recently, an operational implementation of this information theoretic coding strategy, using network coding, has been...
In this paper we propose a joint design of MIMO technique and network coding (MIMO-NC) and apply it to improve the performance of wireless networks. We consider a system in which the packet exchange among multiple wireless users is forwarded by a relay node. In order to enjoy the benefit of MIMO-NC, all the nodes in the network are mounted with two antennas and the relay node possess the coding capability...
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