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Performance of 3T-ANC based orthogonal frequency-division-multiplexed optical wireless link with pointing error

JOURNAL OF OPTICS-INDIA 2019年第3期48卷 400-411页

作者： Kumar, Pravindra Thakor, Satyajit TIET Patiala Punjab India Indian Inst Technol Mandi SCEE Mandi Himachal Prades India

The average channel capacity, achievable rate, and bit error rate (BER) for orthogonal frequency-division multiplexing-based optical wireless (OFDM-OW) links over Gamma-Gamma-distributed atmospheric channel, with pointing errors, are investigated from an information theory perspective. Building sway, heavy wind, ground motion, or differential heating and cooling could result in misalignment (pointing errors) between transmitter and receiver. A relay-assisted OW communication system, with three-time-slotted analog network coding (3T-ANC) scheme, can be used in non-light-of-sight (NLoS) link situation to make successful communication between the users with improved performance in terms of throughput and BER. In the analysis, we show that the 3T-ANC-based OFDM-OW link gives better BER performance and increased achievable rate with narrow beam width and less normalized jitter value.

关键词： OFDM-OW system Gamma-Gamma distribution Pointing error analog network coding

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Optimal Throughput of the ANC based Two-way Relay System with Energy Harvesting 90

Optimal Throughput of the ANC based Two-way Relay System wit...

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90th IEEE Vehicular Technology Conference (IEEE VTC-Fall)

作者： Zhong, Kaiqi Fu, Liqun Xiamen Univ Minist Educ Key Lab Underwater Acoust Commun & Marine Informa Sch Informat Sci & Engn Xiamen 361005 Peoples R China

ISBN: (纸本)9781728112206

This paper investigates the throughput performance of a two-way energy harvesting (EH) relaying system with analog network coding (ANC) scheme. ANC scheme can improve the transmission efficiency of the two-way relay network. Energy harvest is an emerging solution for prolonging the lifetime of wireless node by availing the ambient RF signals. In particular, we focus on the energy harvesting system with the time switching-based relaying (TSR) protocol. We successfully derive the analytical expressions for both the outage probability and the achievable throughput. The analytical result matches with the practical system throughput well. Furthermore, we derive a closed-form approximation of throughput and show that it is a log-concave function of the time-switching (TS) ratio. Therefore, the system throughput optimization can be mathematically formulated as a quasi-convex optimization problem which can be solved efficiently. Simulation results show that the closed-form expression of throughput is log-concave and the gap between the approximated throughput with the practical optimal throughout is less than 10%.

关键词： Two-way relay system analog network coding energy harvesting outage probability throughput

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The Modulation Scheme with Unknown CSI for analog network coding in Multi-Antenna Relay Channel

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Procedia Engineering 2012年 29卷 3364-3370页

作者： Rui Wang Chen Chen Da Wang Haige Xiang School of Electronics Engineering and Computer Science Peking University Beijing China

analog network coding (ANC) is a hot topic in recent pioneer researches. Two end-sources can exchange information with the help of a relay by making use of the additive nature of electro-magnetic waves in the wireless two-way relay channel (TWRC). The relay amplify and forward the XORed signal to both of the two sources. In this paper, we assume that each source is equipped with a single antenna and the relay is equipped with multiple antennas. Neither the sources nor the relay can acquire the channel state information (CSI). We propose a novel modulation scheme based on differential modulation. The receivers in TWRC can eliminate the self-interference when their transmitting signals are independent. Then we derive the maximum likelihood (ML) detector for the ANC system with differential modulation signal. We compare the system bit error rate (BER) performance with coherent detection and perfect CSI. Theoretical and simulated results show that even without the aid of CSI, the performance of the proposed system is approximately 1-2 dB away from the optimal coherent detection scheme.

关键词： analog network coding multi-antenna relay bidirectional relaying differential modulation

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Joint Transmit/Receive MMSE-FDE for MIMO analog network coding in Single-Carrier Bi- Directional Relay Communications

Joint Transmit/Receive MMSE-FDE for MIMO Analog Network Codi...

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IEEE Vehicular Technology Conference

作者： Hiroyuki MIYAZAKI Masayuki NAKADA Tatsunori OBARA Fumiyuki ADACHI Dept. of Electrical and Communication Engineering Graduate School of Engineering Tohoku University

ISBN: (纸本)9781467318808

In this paper, we propose a joint transmit/receive frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion for multi-input multi-output (MEMO) analog network coding (ANC) in single-carrier (SC) bidirectional relay communications. In the proposed scheme, the relay station (RS) equipped with multiple antennas carries out antenna diversity and one-tap transmit FDE, and the base station (BS) and mobile terminal (MT) receivers, both equipped with single antenna, carry out one-tap receive FDE only. The FDE weights at RS, BS and MT are jointly optimized so as to minimize the end-to-end mean square error (MSE). We evaluate, by computer simulations, the bit error rate (BER) performance when using the proposed scheme, and discuss how the transmit FDE at RS operates and affects the BER performance.

关键词： Component analog network coding Frequency-domain equalization Single-carrier transmission bit error rate performance Mean square error diversity reception analog network Relay Communication multiple antenna machine translation MT directional relays Computer Simulation Communication Research

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Channel Estimation Based on Outage Probability in analog network coding

Channel Estimation Based on Outage Probability in Analog Net...

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2012 IEEE 14th International Conference on Communication Technology

作者： Zhaolong Ning Qingyang Song Lei Guo School of Information Science and Engineering Northeastern University

ISBN: (纸本)9781467321006

network coding is an emerging technique of packet forwarding that encodes the packets at a relay node in the network *** network coding (ANC) encodes the packets by superposing signals at the physical layer,which can further bring throughput *** most previous literatures assume either channel parameters are pre-established or perfect global channel state information (CSI) can be obtained by the relay node,which is unrealistic for a wireless *** this paper,we propose a scheme to estimate channel gains based on outage probability by varying the sampling window in a multi-user two-way relay network,and present a sum rate optimization opportunistic scheduling scheme as an application of the channel estimation *** results are presented to demonstrate the effectiveness of our estimation scheme,and the proposed scheduling scheme outperforms the conventional round robin scheduling scheme significantly.

关键词： analog network coding outage probability opportunistic scheduling two-way relay network.

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An effective channel estimation scheme for bi-directional two-timeslot OFDM relay transmission using analog network coding

An effective channel estimation scheme for bi-directional tw...

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IEEE Vehicular Technology Conference

作者： Yuta Koshimizu Eiji Okamoto Department of Computer Science and Engineering Graduate school of Engineering Nagoya Institute of Technology Gokiso-cho Showa-ku Nagoya-shi 466-8555 Japan

ISBN: (纸本)9781467309899

Recently, relay transmission schemes have been much studied according to increasing demands for ad-hoc wireless communication. In bi-directional relay transmission, the transmission efficiency has been decreased due to the waiting time. To tackle this problem, network coding (NC) has been proposed. The orthogonal frequency division multiplexing (OFDM)-based relay transmission applying analog network coding (ANC) can reduce the number of timeslots per one sequence compared to that without NC and it increases the transmission capacity. However, in the bi-directional relay transmission with ANC, the relay node receives the signals of each transmitting nodes simultaneously and the signal detection must be conducted. To do that, the channel state information of each nodes is needed, and the rate-efficient and accurate channel estimation should be applied for the bidirectional relay, which is not much considered so far. Therefore, in this paper, we propose a new channel estimation scheme for bidirectional two-timeslot OFDM relay transmission where the transmitters send sparse Walsh-code pilots and the receiver detects and estimates each channel information by the correlation processing. The proposed scheme can estimate the channels by less pilot symbols sparsely allocated in OFDM frame. In addition, an accurate interpolation scheme with two-dimensional fast Fourier transform (FFT) is utilized. The performances of the proposed scheme are evaluated by computer simulations.

关键词： effective channel estimation scheme bi-directional two-timeslot analog network coding relay transmission channel estimation analog network Orthogonal frequency division multiplexing bidirectional relay signal acquisition Channel state information information channels transmission capacity Trunk Node Scheme transmission efficiency

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Optimized Cooperative Multiple Access in Industrial Cognitive networks

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IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS 2018年第6期14卷 2666-2676页

作者： Li, Nan Xiao, Ming Rasmussen, Lars K. KTH Royal Inst Technol Sch Elect Engn S-10044 Stockholm Sweden KTH Royal Inst Technol ACCESS Linnaeus Ctr S-10044 Stockholm Sweden

We consider optimized cooperation in joint orthogonal multiple access and nonorthogonal multiple access in industrial cognitive networks, in which lots of devices may have to share spectrum and some devices (e.g., those for critical control devices) have higher transmission priority, known as primary users. We consider one secondary transmitter (less important devices) as a potential relay between a primary transmitter and receiver pair. The choice of cooperation scheme differs in terms of use cases. With decode-and-forward relaying, the channel between the primary and secondary users limits the achievable rates especially when it experiences poor channel conditions. To alleviate this problem, we apply analog network coding to directly combine the received primary message for relaying with the secondary message. We find achievable rate regions for these two schemes over Rayleigh fading channels. We then investigate an optimization problem jointly considering orthogonalmultiple access and nonorthogonal multiple access, where the secondary rate is maximized under the constraint of maintaining the primary rate. We find both analytical solutions as well as solutions based on experiments through the time sharing strategy between the primary and secondary system and the transmit power allocation strategy at the secondary transmitter. We show the performance improvements of exploiting analog network coding and the impacts of cooperative schemes and user geometry on achievable rates and resource sharing strategies.

关键词： analog network coding industrial cooperative networks nonorthogonal multiple access optimization spectrum sharing

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analog network coding in the Generalized High-SNR Regime

Analog Network Coding in the Generalized High-SNR Regime

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IEEE International Symposium on Information Theory (ISIT)

作者： Liu, Binyue Cai, Ning Xidian Univ State Key Lab ISN Xian 710071 Peoples R China

ISBN: (纸本)9781457705953

In a recent paper [4], Maric et al. analyzed the performance of the analog network coding (ANC) in a layered relay network for the high-SNR regime. They have proved that under the ANC scheme, if each relay transmits the received signals at the upper bound of the power constraint, the transmission rate will approach the network capacity. In this paper, we consider a more general scenario defined as the generalized high-SNR regime, where the relays at layer l in a layered relay network with L layers do not satisfy the high-SNR conditions, and then determine an ANC relay scheme in such network. By relating the received SNR at the nodes with the propagated noise, we derive the rate achievable by the ANC scheme proposed in this paper. The result shows that the achievable ANC rate approaches the upper bound of the ANC capacity as the received powers at relays in high SNR increase. A comparison of the two ANC schemes implies that the scheme proposed in [4] may not always be the optimal one in the generalized high-SNR regime. The result also demonstrates that the upper and lower bounds of the ANC rate coincide in the limit as the number of relays at layer L-1 dissatisfying the high-SNR conditions tends to infinity (to be infinite), yielding an asymptotic capacity result.

关键词： Encoding network coding Relays Signal to noise ratio Upper bound Wireless communication analog network coding asymptotic capacity channel capacity generalized high-SNR regime layered relay network lower bounds network capacity network coding power constraint propagated noise telecommunication network routing transmission rate upper bounds

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Outage-optimal opportunistic scheduling with analog network coding in multiuser two-way relay networks

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EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND networkING 2011年第1期2011卷 1-12页

作者： Upadhyay, Prabhat K. Prakriya, Shankar Indian Inst Technol Delhi Dept Elect Engn New Delhi 110016 India

This paper investigates the performance of an outage-optimal opportunistic scheduling scheme for a multiuser two-way relay network, wherein an analog network coding-based relay serves multiple pairs of users. Under a Rayleigh flat-fading environment, we derive an exact expression for cumulative distribution function (CDF) of the minimum of the two end-to-end instantaneous signal-to-noise ratios (SNRs) and utilize this to obtain an exact expression for the outage probability of such a greedy scheduling scheme. We then develop a modified scheduler that ensures fairness among user pairs of the considered system. By using a high SNR approximation of derived CDF, we present a simple closed-form expression for outage probability of the overall system and establish that a multiuser diversity of order equal to the number of user pairs is harnessed by the scheme. We also present an efficient power allocation strategy between sources and relay, subject to a total power constraint, that minimizes the outage probability of the overall system. Further, by deriving both upper and lower bound expressions for the average sum-rate of the proposed scheme, we demonstrate that an average sum-rate gain can also be achieved by increasing the number of user pairs in the system. Numerical and simulation results are presented to validate the performance of the proposed scheme.

关键词： analog network coding Multiuser scheduling Outage probability Rayleigh fading Two-way (bidirectional) relaying

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Non-Regenerative Multi-Way Relaying: Space-Time analog network coding and Repetition

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IEEE COMMUNICATIONS LETTERS 2011年第12期15卷 1362-1364页

作者： Amah, Aditya Umbu Tana Klein, Anja Tech Univ Darmstadt Grad Sch Computat Engn Darmstadt Germany Tech Univ Darmstadt Commun Engn Lab D-64283 Darmstadt Germany

In this letter, we investigate non-regenerative multi-way relaying when channel state information is not available at the multi-antenna relay station (RS). For stationary channels, space-time analog network coding (STANC) transmission is applied at the RS. For non-stationary channels, the RS applies repetition transmission. For both transmission schemes, in order to obtain the data streams of the other nodes, each node has to perform three receive processing operations successively: Zero Forcing (ZF) detection, back-propagated self-interference cancellation and joint detection. We assess the achievable sum rate performance of non-regenerative multi-way relaying for the proposed transmission schemes. It is shown that STANC with joint detection outperforms both benchmark transmissions, namely, ZF and Maximisation of Signal to Noise Ratio (MSNR) transceive beamforming with single stream decoding performed at each node. When the channels are non-stationary, the repetition transmission enables the multi-way communication and in medium to high SNR region, it outperforms MSNR.

关键词： Multi-way relaying analog network coding space-time block code

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