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In this work, we implement and demonstrate differential amplify-and-forward (DAF) cooperative relaying as a novel diversity technique to combat bit errors and outages common in airborne environments. By using differential modulation and demodulation, we reduce the system complexity by avoiding channel estimation which is often unreliable or computationally costly in dynamic environments with mobile...
Energy accumulation is an approach to reducing the power consumption of broadcast. In conventional approaches, a node can decode the message if the received power from a single transmission is above a threshold. In contrast, in the cooperative approach based on energy accumulation, a node can decode the message if the sum of the received powers from any set of transmissions exceeds the threshold....
This work studies the performance of a cooperative network which consists of two channel-coded sources, multiple relays, and one destination. Due to the spectral efficiency constraint, we assume that a single time slot is dedicated to relaying. Conventional network-coded based cooperation (NCC) selects the best relay which uses network coding to serve the two sources simultaneously. It is shown that...
In this paper, we investigate the secrecy performance of multiuser dual-hop relay networks where a base station (BS) communicates with multiple legitimate users via the assistance of a trustful regenerative relay in the presence of multiple eavesdroppers. In particular, the maximal ratio transmission (MRT) scheme is exploited at the BS and a threshold-based multiuser scheduling scheme is employed...
In this paper, the secrecy of a cooperative system consisting of a single source, relay, destination and eavesdropper is analyzed. The threshold-selection decode-and-forward relay is considered, where the relay can correctly decode and forward only if it satisfies a threshold signal-to-noise ratio (SNR). Both destination and eavesdropper take advantage of the direct and relayed transmissions through...
Satellite communication plays an important role in the ubiquitous global communication. However, for a long time, the communication provided by satellite suffers from serious signal attenuation and transmission delay. Conventional techniques such as HARQ couldn't provide timely service unless powerful channel codes are used. Once channel code fails, retransmission will be inevitable, and unbearable...
This paper considers differential amplify-and-forward (D-AF) relaying system employing differential encoding and decoding over time-varying fading channels. A practical multiple-symbol differential sphere detection (MSDSD) is designed to overcome the error floor, which the convectional 'two-symbol' differential detection (CDD) reaches at high signal-to-noise ratio region in fast-fading channels. The...
In this paper, we propose the SNR weighted LLR combining method in uplink mmWave multi-beams environment. Until now, the mmWave band has been considered as a candidate for new radio band for 5G mobile communication system. Because the mmWave band has good directivity, we can make sharp beam by applying beamforming technology using a plurality of antenna elements. The BS can have the antenna configuration...
Multiple-input multiple-output (MIMO) systems are commonly used in wireless communications to ensure high bit-rate and high capacity transmission. Space time block coding (STBC) is a technique used in MIMO to provide transmit diversity in communication over fading channels. Although STBC has full diversity gain, the coding gain need to be improved by using channel coding such as low density parity...
The performance of the iteration combining-equalization (ICE) and its frequency domain implementation for high frequency high data rate transmission systems is excellent. However the convergence of the algorithm is difficult to analysis due to the iterative processing is used. In order to solve this problem, a performance analysis method is proposed through following the mutual information transfer...
The bidirectional fractionally-spaced decision feedback equalizer (DFE) based on the soft outputs combination is proposed. Without any channel estimation, the fractionally-spaced DFE effectively compensates for any phase distortion and suppresses the error propagation. Compared to conventional methods, the soft outputs combining scheme involving the log likelihood ratios (LLRs) of two DFEs outputs...
This paper investigates the outage behavior of transmitting correlated binary sources with arbitrary code rate over quasi-static Rayleigh fading multiple access channel (MAC). The sufficient condition for lossless communication with arbitrary code rate is obtained by assuming separate source and channel coding, which indicates the two rate regions specified by the Slepian-Wolf theorem and the MAC...
Nonergodic fading is a useful model for various wireless communication channels in both indoor and outdoor environments. With this model, a codeword is divided into multiple blocks such that fading is constant within a block and independent across blocks. Building on Poltyrev's work on infinite lattice constellations for the Gaussian channel, we derive a Poltyrev outage limit for lattice constellations...
Three new Block Code Diversity combing schemes for digital transmission over a Rayleigh fading channel have been proposed. It has been shown that improved performance in term of probability of error versus signal to noise ratio has been obtained using soft-decision Viterbi decoding together with diversity techniques. Simulation results have been included to verify the performance of the proposed schemes.
PAM-DMT is a transmission technique for IM/DD channels that can be effectively employed without a DC bias, by using only the quadrature component of QAM constellations. In this contribution, and based on an algorithm previously employed for AC-DMT [8], we show that the non-linear distortion that falls onto the in-phase component of the received signal also contains useful information, and can be adequately...
This paper presents a stochastic geometry model for studying spatiotemporal base station cooperation in a cellular network. Unlike most previous related works in the literature, the paper focuses on the coverage probability at the typical cellcorner user, i.e., a user that is equidistant to its three neighboring base stations (BSs). Three schemes are considered: joint transmission, base station silencing,...
Channel conditions on satellite communication systems are changed continuously. The Rate Compatible Punctured Turbo (RCPT) Codes Hybrid Automatic Repeat Request (HARQ) have been shown to improve reliable communications by adapting varying channel conditions. The paper discusses the throughput performance and transmission numbers of three HARQ schemes including partial incremental redundancy (partial-IR)...
This paper proposes 2×2 MIMO OQAM/FBMC receiver strategy based on successive interference cancellation (SIC) as an extension of the SISO approach which uses entirely real-valued formulation of the transmission system model]. Both increase of throughput and SNR gain are observed through appropriate maximum ratio combining (MRC) of the soft symbols pertaining to the receiver-end diversity branches....
In this paper, we propose a novel scheme coined opportunistic space-time coding (OSTC) to deal with the outdated channel state information (CSI) problem for opportunistic relay selection (ORS) systems. A pair of relays, instead of a single relay, is opportunistically selected in terms of the instantaneous CSIs. Alamouti scheme, a unique space-time code achieving both full-rate and full-diversity,...
Analog joint source channel coding techniques for a discrete time analog system is proposed and analyzed. The proposed system has all-analog-processing joint source-channel coding with MMSE, ML. Utilization of multiple antennas helps in bridging performance margin between ML and MMSE which arises in high signal to noise (SNR) scenario. Further, spatial diversity is proposed as a viable alternative...
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