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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,...
Recently, we proposed a novel transmission scheme termed decomposed-quadrature optical single carrier frequency domain equalization (DQO-SCFDE) suitable for intensity-modulated direct-detection (IM/DD) diffuse optical wireless (DOW) communication. DQO-SCFDE has been shown to perform better than the conventional asymmetrically clipped optical OFDM (ACO-OFDM) when the non-linearity characteristics of...
In this paper, we propose high-rate distributed space-time-frequency codes (DSTFCs) to exploit maximum achievable diversity gains over frequency-selective fading channels. The proposed designs achieve full-rate for any number of cooperative nodes, and allow channel variations over multiple OFDM blocks within one DSTFC codeword. We analyze diversity gains of DSTFCs through both conditional and average...
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, 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...
We study the performance of per-tone transmit antenna selection in OFDM systems with Alamouti coding. In particular, we analyse the diversity and coding gains of such systems, and compare these gains with the respective performance metrics for single-antenna selection performed on a pertone basis. Our analysis demonstrates that although the gain of single-antenna selection is superior to that of Alamouti...
The concept of STNC is very general. Fundamentally, it involves combining information from different sources at a relay node, which gives rise to the concept of network coding, and transmitting the combined signals in dedicated time slots from various locations in a network, which makes the space-time concept. Various traditional combining techniques can be used, including CDMA-like and OFDMA-like...
Alamouti space-time coding is investigated in conjunction with OFDM modulation for high-rate underwater acoustic communications over time varying channels. The scheme's diversity gain is exploited using a low-complexity adaptive multichannel receiver. Performance is demonstrated using experimental data transmitted in a 10 kHz bandwidth over a 1 km shallow water channel south of the Martha's Vineyard...
Filter bank based multicarrier (FBMC) is an interesting alternative to OFDM especially for spectrally agile communication waveform generation and for cognitive radio scenarios. For enhanced link performance and robustness, most of the common multi-antenna schemes can be combined with FBMC equally well as with OFDM. However, one significant shortcoming of FBMC is the difficulty of combining it with...
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...
The performance of a wireless communication system is analyzed considering multi-carrier OFDM with Multiple- Input-Multiple-Output (MIMO) wireless channel and Space-Time Block Coding (STBC). Bit Error Rate (BER) expression for MIMO-OFDM system without and with STBC is presented considering fading and timing jitter with QPSK, DPSK and DQPSK modulation schemes. The performance results are evaluated...
A space-time coding scheme based on interleave division multiplexing (EDM) is investigated over an orthogonal frequency division multiplexing (OFDM) link that employs multiple transmit antennas. The performance of an iterative receiver structure for the proposed scheme over a quasi-static channel is evaluated via simulation, and its advantages are shown by comparison to other space-time schemes in...
In forward link multiuser space-time block coded orthogonal frequency division multiplexing (STBC-OFDM) systems, the signal-to-noise power ratio (SNR) of each user's received signal is different from those of others. Thus, when subcarriers are not properly allocated to users, intensive bit errors occur in a specific user. This causes a burst error in such a user, and the number of correctable bits...
A distributed space-time-frequency (STF) coding scheme is proposed for cooperative OFDM (C-OFDM) systems with three terminals over quasi-static frequency-selective Rayleigh fading channels. The outage probability performance is derived and its tight closed-form lower bound is presented. Asymptotic analysis indicates that the proposed scheme can achieve both spatial and multipath (frequency) diversity...
Due to a great many redundancy symbols, most of the existing differential space-time-frequency (DSTF) coding schemes suffer very low transmission rates. To overcome the disadvantage and obviously enhance the total transmission rate in a differential multiple-input-multiple-output (MIMO) orthogonal-frequency-division-multiplexing (OFDM) system, a rate embedded doubly directional DSTF coding scheme...
This paper deals with the problem of code design for non-coherent frequency-selective Multiple Input Multiple Output (MIMO)-Orthogonal Frequency Division Multiplexing (OFDM) fading links, where neither the transmitter nor the receiver knows the channel. A simple and classical approach for non coherent (NC) coding for MIMO-OFDM system consists of coding across antennas and time slots on each OFDM subcarrier...
Future Communication networks are tending towards a diverse wireless networking world where the positioning information (PI) could be helpful in different techniques like the dynamic resource allocation. On the other hand, the PI could be widely used for cooperative techniques in the relay and/or routing selection process. In this paper, we propose to use the PI in the selection of the relays and...
To alleviate the high peak-to-average power ratio (PAPR), high complexity in user terminal and sensitivity to carrier frequency offset (CFO) problems in current OFDMA systems, a Quadrature OFDM (Q-OFDMA) system has been recently proposed in the single-input single-output environment. In this paper we investigate the realization of multi-input multioutput (MIMO) diversity- and capacity- oriented methods...
Multiple Input Multiple Output (MIMO) is a topic of high interest for the next generation of broadcasting systems. However, their deployment in single frequency networks (SFN) becomes more critical when they are used in hybrid satellite-terrestrial transmission due to the different aspects of the respective transmission links. In this paper, we propose to apply a double layer space time block code...
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