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Cooperative relay has been an interesting research area for the past years as it promotes higher data rates and robust to wireless environment. IEEE Work Group initiated the use of relay stations in the IEEE 802.16e standard and it is called IEEE 802.16j. This paper proposed a multi-hop cooperative relay system with space-time codes (STC), with the integration of relay selection. In changing environment,...
In highly spatially correlated channels the diversity gain achieved by space-frequency (SF) coding is significantly low. Nevertheless, when full or partial channel state information is available at the transmitter, improved performance can be obtained by combining transmit beamforming with SF coding. In this paper we propose two novel transmit beamforming techniques based on the minimum pair-wise...
In Multi-user MIMO (MU-MIMO), the Base Station (BS) schedules multiple users simultaneously on the same resources. Closed loop MU-MIMO uses explicit feedback from each of these users for scheduling and allocation of resources. In this scheme, an estimate of the SINR experienced is fed back by each user and is known as the CQI (Channel Quality Information). This CQI is used by the BS for link adaptation...
We consider Gaussian multiple-input multiple-output (MIMO) channels with discrete input alphabets. We propose a non diagonal precoder based on the X-Codes in to increase the mutual information. The MIMO channel is transformed into a set of parallel subchannels using singular value decomposition (SVD) and X-Codes are then used to pair the subchannels. X-Codes are fully characterized by the pairings...
In the IEEE 802.16d Orthogonal Frequency Division Multiplexing (OFDM) physical layer protocol, which provides the Space-Time Coding (STC) scheme to improve system performance, it is possible to get a better performance in resisting multipath fading and increasing bandwidth efficiency. However, in projects, using Multiple-Input Multiple-Output (MIMO) multiple-antenna technology is usually inconvenient...
In this paper, the authors have proposed a multiuser Space frequency (SF) code with high symbol rate and full-diversity. This SF code is constructed from a threaded algebraic layering concept. It combines the space-frequency layering concept with algebraic component codes where each component code is assigned to a “thread” and interleaved over space and frequency. It is proved...
The capacity of the symbol-asynchronous single-relay channel with multipath is investigated. Due to the slow propagation speed of sound in water and surface/floor reflections, such channels are highly relevant to underwater acoustic communication systems. The symbol-asynchronous single-relay channel can be modeled as a MIMO relay channel with memory; thus MIMO capacity results can be invoked to determine...
Multiple-input multiple-output (MIMO) is a promising technology to enhance capacity and robustness of the link by the presence of multiple transmit antennas and multiple receive antennas in the communication link. The use of multiple antennas at both ends of a wireless link promises significant improvements in terms of spectral efficiency and link reliability. The HF system adopted MIMO and OFDM(Orthogonal...
The Digital Video Broadcasting second generation Terrestrial (DVB-T2) standard purposes to provide high definition digital video and high rate services for the same spectrum allocation of the current Digital Video Broadcasting Terrestrial (DVB-T) standard. The implementation guideline is provided by the DVB-T2 standardization community, the Digital Video Broadcasting (DVB) Project. The DVB Project...
Imperfections in analog circuits are serious obstacles to the realization of high data rate transmission for multiple-input multiple- output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) systems. An I/Q imbalance is one of such imperfections affecting the up- and down-conversions of quadrature modulators and demodulators in RF front-ends of transceivers. In this paper, we consider MIMO...
The cooperative techniques have recently taken a lot of attention in the recent few years due to their efficiency in radio mobile networks specially when the direct link between the source and the destination is lost. However, their combination with the multiple input multiple output (MIMO) schemes requires further study since new strategies of cooperation are expected when the MIMO component is added...
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...
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...
In this paper, we propose a 2 × 2 cooperative multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) scheme based on Alamouti space-time coding. In this scheme, the the relay and the destination antennas receive the transmitted symbols from the source during the first stage. Then, both the relay and the destination generate their own decision variables using an Alamouti...
Interference coordination methods for Evolved-Multimedia Broadcast/Multicast Service (E-MBMS) in Long Term Evolution Advanced (LTE-A) are presented. In this paper, OFDM/OFDMA signals based on LTE parameters are combined with MIMO, Turbo codes and signal space diversity methods. Different interference coordination techniques, such as, MIMO coordination, Fixed Relay stations and adaptive frequency reuse...
The second generation terrestrial transmission standard DVB-T2 introduces the application of MIMO techniques based on the well-known Alamouti scheme for improved mobile and portable reception. However, no channel models are currently available to estimate the gain of Alamouti coding in these channels. Therefore, this document presents a new approach that uses existing DVB-T networks as channel sounder...
In this paper, in order to achieve the available spatial, temporal and frequency diversities, and also make the system implementation feasible for high speed orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) multiplexing, a novel LSTF transmitter architecture with multiple channel encoders is proposed with each independently coded information sub-stream being...
This paper is focused on the study of layered space-time-frequency (LSTF) architectures with channel coding for orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) multiplexing systems for high speed wireless communications over a frequency-selective fading channel. In order to achieve the available spatial, temporal and frequency diversities, and also make the...
There is narrow space and harsh environment underground coal mines. When radio signals are transmitted, diffraction, attenuation, multi-path and scattering are often very serious. All the problems make the WSN system difficult to reach the set bit error rate when transmitting images. V-MIMO, which makes every node of the WSN work together, is adopted in the paper. In order to improve the system capability...
This paper proposes a space-time-frequency coding scheme for MIMO-OFDM that achieves full rate for an arbitrary number of antennas with complex-valued information symbols. In addition, the proposed scheme provides a very high level of diversity with relatively low complexity. In the new scheme, the spatial and frequency spreading is followed by a temporal spreading that facilitates simple separation...
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