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We consider a time division duplex multiple-input multiple-output (nt × nr MIMO). Using channel state information (CSI) at the transmitter, singular value decomposition (SVD) of the channel matrix is performed. This transforms the MIMO channel into parallel subchannels, but has a low overall diversity order. Hence, we propose X-Codes which achieve a higher diversity order by pairing the subchannels,...
Network coding is considered as a promising technique to improve diversity gain and network throughput in multi-source relay systems. This paper presents an opportunistic network coded cooperation scheme in wireless multi-unicast system with non-ideal source-relay channels. In the conventional network-coding-based cooperation schemes, the relay merges the messages received from multiple sources and...
In this paper, we investigate the performance of a cooperative network with adaptive decode-and-forward (DF) relaying over time-selective frequency-flat Rayleigh fading channels. In adaptive DF relaying, only a subset of the available relays with "good" channels are allowed to participate in the relaying phase. The destination combines the direct and the relayed signals using maximal ratio...
Performance of a decode-and-forward (DF) based two-hop multiuser cooperative transmission system is usually restricted by the link quality between a base station (BS) and a relay station (RS) as the number of users grows. Thus the BS-RS link quality should be improved to enhance the performance. In this paper, we propose two-hop cooperative communication systems with multiple receive antennas at the...
Improvement in hostile wireless communication highly varying channel with is done by several ways like channel coding, diversity and equalization. Recently a new family of codes known as turbo codes is incorporated in 3G and 4G wireless standards. It has capability of performing close to Shannon Limit. In this paper we compare performance of convolution code for IS -95 and turbo coded CDMA 2000 over...
Conventional cooperative relaying schemes usually process the network CSI in a centralized way by setting one central node where decisions, such as relay selection, are made by relying on information from all channels. In this paper, we propose a novel distributed relay selection scheme for Decode-and- Forward networks. In this scheme, each relay decides to participate in cooperation based on link...
The performance of bit-interleaved coded modulation-iterative decoding (BICM-ID) based cooperative network is analyzed over Rayleigh and Nakagami-m fading channels. The relays are assumed to be operating in amplify-and-forward (AF) configuration. The bit error rate (BER) bounds of single-relay cooperative system with the serial concatenated BICM-ID using the 8-PSK modulations with maximal ratio combining...
This paper focuses on turbo packet combining strategies for multi-relay-assisted systems operating over multiple-input-multiple-output (MIMO) broadband channel. We propose a frequency domain minimum mean square error (MMSE)-based turbo packet combining scheme where all slots received signals and their corresponding channel frequency responses (CFR)s are used to decode the data packet. We also provide...
The amplify-and-forward (AF) and the decode-and-forward (DF) cooperative coded diversity is compared with the conventional receiver coded diversity in terms of the bit error rate (BER). The comparison assumes channel coding with non-binary modulations, and fast fading channels with path-loss attenuation proportional to the distance between nodes. Numerical results obtained by extensive computer simulations...
Trellis Coded Spatial Modulation (TCSM) is a novel transmission technology for Multiple-Input-Multiple-Output (MIMO) systems, which has been recently proposed to improve the performance of Spatial Modulation (SM) over correlated fading channels. The fundamental principle of TCSM is to use convolutional encoding and Maximum-Likelihood Sequence Estimation (MLSE) decoding to increase the free distance...
We consider the application of switch-and-stay transmit diversity (SSTD) to a three-node cooperative diversity system with decode-and-forward relaying. The basic idea of SSTD generally is to use a certain transmit antenna as long as the induced signal quality satisfies a given requirement while the transmitter switches to another antenna element if this is no longer the case. Applying this principle...
Cooperative diversity has recently been proposed as a promising technology to achieve spatial diversity in wireless networks. In this paper, we analyze the performance of SNR-based hybrid decode-amplify-forward (HDAF) relaying cooperative diversity networks over independent non-identical flat Rayleigh fading channels with maximum ratio combining (MRC) technique. Closed-form expressions for the outage...
We derive detection metrics for soft-output diversity combining for the case of imperfect channel state information at the receiver. We treat in particular the case when the noise variance at the receiver is unknown. We contrast conventional training-based methods to a detector based on the generalized likelihood-ratio (GLR) test paradigm. We study the performance of the detectors via EXIT chart analysis...
In this paper, a low-complexity protocol for the K-parallel-path multihop channel is proposed. This protocol is based on a smart path selection combined with a small space-time code. It is proven to achieve full rate and full diversity, and to reach the optimum diversity-multiplexing gain tradeoff d*(r)=K(1-r)+. Some implementation issues such as the frame length or interferences between paths are...
This paper addresses the question whether decode-and-forward relaying protocols can beat transmit diversity with respect to ε-outage capacity. We derive expressions of ε-outage capacity for transmit diversity, decode-and-forward, selective decode-and-forward, and incremental decode-and-forward. We demonstrate that the relaying protocols outperform transmit diversity in certain regions. Decode-and-forward...
For a two hop cooperative relay communication system, the first hop mainly gets the diversity gain, and the second hop gets the cooperative gain. While HARQ gets the time diversity gain, space-time or the others coding has the chance to get a tradeoff between diversity gain and multiplex gain. It is significant to combine the HARQ and STBC in a cooperative MIMO system that formed by a set of cooperative...
A realistic framework for cooperation diversity is presented for Orthogonal Frequency Division Multiplexing (OFDM) systems with clipping type of transmitter non-linearities. The destination node processes together the received information from the source node and a single, selection algorithm dependent relay one (if any of the candidate relays succeeds in decoding the original OFDM packet sent). The...
In this paper, we consider the improvement of the macro and micro diversity by the help of relays using a dynamic decode and forward (DDF) protocol. We first derive bounds on the macro and micro diversity for DDF and Patched-DDF protocols using distributed Mono-stream and Alamouti schemes. We then derive an auto-organized behavior of the relay that maximizes the macro and micro diversity of the broadcast...
In this paper, we investigate packet-level non-altruistic node cooperation in wireless networks with regenerative nodes. Since each node has its own data to transmit, pure relays do not exist. We prove that the split of transmit power has no impact on the diversity performance of non-altruistic cooperative transmissions. Despite the beneficial diversity gain, our results show that non-altruistic cooperative...
We consider the joint exploitation of coding and diversity techniques to achieve efficient, reliable wireless transmission. The system of interest comprises a powerful non-binary low-density parity-check (LDPC) code that will be soft-decoded to supply strong error protection, a quadratic amplitude modulator (QAM) that directly takes in the non-binary LDPC symbols and will be soft-demodulated, and...
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