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Delay-Optimal Broadcast for Multihop Wireless networks Using Self-Interference Cancellation

IEEE TRANSACTIONS ON MOBILE COMPUTING 2013年第1期12卷 7-20页

作者： Zhang, Xinyu Shin, Kang G. Univ Michigan Dept Elect Engn & Comp Sci Real Time Comp Lab Ann Arbor MI 48109 USA

Conventional wireless broadcast protocols rely heavily on the 802.11-based CSMA/CA model, which avoids interference and collision by conservative scheduling of transmissions. While CSMA/CA is amenable to multiple concurrent unicasts, it tends to degrade broadcast performance significantly, especially in lossy and large-scale networks. In this paper, we propose a new protocol called Chorus that improves the efficiency and scalability of broadcast service with a MAC/PHY layer that allows packet collisions. Chorus is built upon the observation that packets carrying the same data can be effectively detected and decoded, even when they overlap with each other and have comparable signal strengths. It resolves collision using symbol-level interference cancellation, and then combines the resolved symbols to restore the packet. Such a collision-tolerant mechanism significantly improves the transmission diversity and spatial reuse in wireless broadcast. Chorus' MAC-layer cognitive sensing and scheduling scheme further facilitates the realization of such an advantage, resulting in an asymptotic broadcast delay that is proportional to the network radius. We evaluate Chorus' PHY-layer collision resolution mechanism with symbol-level simulation, and validate its network-level performance via ns-2, in comparison with a typical CSMA/CA-based broadcast protocol. Our evaluation validates Chorus's superior performance with respect to scalability, reliability, delay, etc., under a broad range of network scenarios (e.g., single/multiple broadcast sessions, static/mobile topologies).

关键词： Optimal broadcast wireless ad hoc and mesh networks collision resolution multipacket reception self-interference cancellation analog network coding

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Impact of Channel Estimation Error on Bidirectional MABC-AF Relaying With Asymmetric Traffic Requirements

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2013年第4期62卷 1755-1769页

作者： Li, Jing Ge, Jianhua Zhang, Chensi Shi, Jingjing Rui, Yun Guizani, Mohsen Xidian Univ State Key Lab Integrated Serv Networks Xian 710071 Peoples R China Chinese Acad Sci Shanghai Adv Res Inst Shanghai 201203 Peoples R China Qatar Univ Doha 2713 Qatar

Channel estimation error results in severe performance deterioration in wireless networks. In this paper, we study the impact of imperfect channel estimation (ICE) on the outage performance of bidirectional relaying where the two sources have asymmetric traffic requirements (ATRs). In particular, we focus on the amplify-and-forward (AF) relay-assisted multiple-access broadcast (MABC) protocol, i.e., MABC-AF, which has received much attention due to its high spectrum efficiency and low complexity. In the single-relay scenario, we derive exact and generalized closed-form expressions for system outage probability, which indicate that the system outage is determined by the unidirectional outage in the case of highly asymmetric traffic patterns. For more insights into our approach, the closed-form asymptotic expressions are also evaluated, manifesting the interesting error floor (EF) phenomenon due to ICE. Using these analytical results, we further develop a robust and practical optimum power-allocation (OPA) algorithm that minimizes the system outage probability under aggregate and individual node power constraints. In the multirelay scenario, by taking into account the traffic knowledge, a novel relay selection criterion is proposed for asymmetric MABC-AF, followed by its impact on the system outage probability in the presence of ICE. Numerical results validate the accuracy of our analytical results and highlight the effect of the proposed OPA algorithm under various traffic requirements and channel estimation errors. Furthermore, the results also show that the proposed relay selection criterion is superior to the classical max-min criterion with ATRs, and the performance improvement becomes remarkable as channel estimation error increases.

关键词： analog network coding asymmetric traffic channel estimation error outage probability power allocation relay selection

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Stochastic policy-based wireless energy harvesting in green cognitive radio network

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EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND networkING 2015年第1期2015卷 1页

作者： Oh, Hayoung Ran, Rong Soongsil Univ Dept Elect & Informat Engn Seoul South Korea Ajou Univ Dept Elect & Comp Engn Suwon 441749 South Korea

With the rapid increase of energy consumption and environment problems, the need for green techniques and harvesting energy is emerging. network coding can provide the solution by the reduction of the unnecessary data transmission and the estimated traffic patterns. It can also amplify the synergy in an energy harvesting capable cognitive radio (CR) network since the CR has the recognition and optimal decision functionalities. In this paper, we propose stochastic policy based wireless energy harvesting in green cognitive radio network. With the simulations, we show that the proposed scheme is better up to 20 % of the previous work.

关键词： Green cognitive radio network analog network coding Linear network coding

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Feasibility and Optimization of 1-TTI-Based Full-Duplex Two-Way Relay System

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WIRELESS PERSONAL COMMUNICATIONS 2020年第3期110卷 1513-1522页

作者： Chang, Kapseok Choi, Yonghoon UST ETRI Daejeon South Korea Chonnam Natl Univ Dept Elect Engn Gwangju South Korea

Maximizing system capacity is one of the major concerns in inband full-duplex (IFD) two-way relay (TWR) system using analog network coding (ANC). This paper compares 1-transmission-time-interval (TTI)-based ANC (1TA) TWR, in which each node operates in IFD mode, with 2-TTI-based ANC (2TA) TWR operating in inband half-duplex mode. System capacity of the 1TA TWR is derived with adverse factor such as direct link interference (DLI). Also, this work proposes an iterative optimal power allocation (OPA) method to maximize the system capacity, which is based on golden section search under total power constraint. Numerical results elucidate that the 1TA TWR based on the OPA outperforms the 2TA TWR in all cases of relay position and DLI.

关键词： analog network coding In-band full duplex Optimal power allocation Two-way relay

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Parallel Two-Way Relaying in Cooperative OFDMA Cellular Systems

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2016年第1期64卷 48-59页

作者： Jin, Sai Ping, Li City Univ Hong Kong Dept Elect Engn Hong Kong Hong Kong Peoples R China

We consider a parallel two-way relaying orthogonal frequency division multiple access (PTWR-OFDMA) scheme based on analog network coding in which mobile terminals (MTs) are divided into near-nodes (NNs) and far-nodes (FNs). An NN communicates with the base station (BS) directly while an FN communicates indirectly via the assistance of NNs. We study the design and analysis issues for PTWR-OFDMA. The proposed scheme has some noticeable advantages. First, the throughput of PTWR-OFDMA increases like, In K, much higher than that of In In K in conventional OFDMA (K is the number of MTs). Second, PTWR-OFDMA can provide much better fairness than conventional OFDMA. Third, the power overhead per NN reduces quickly when K increases if there is a peak rate limitation, implying that there is no strong incentive for some users to avoid providing relaying.

关键词： analog network coding cooperative communication OFDMA two-way relaying

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Non-Regenerative Multi-Antenna Multi-Group Multi-Way Relaying

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

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

We consider non-regenerative multi-group multi-way (MGMW) relaying. A half-duplex non-regenerative multiantenna relay station (RS) assists multiple communication groups. In each group, multiple half-duplex nodes exchange messages. In our proposal, the required number of communication phases is equal to the maximum number of nodes among the groups. In the first phase, all nodes transmit simultaneously to the RS. Assuming perfect channel state information is available at the RS, in the following broadcast (BC) phases the RS applies transceive beamforming to its received signal and transmits simultaneously to all nodes. We propose three BC strategies for the BC phases: unicasting, multicasting and hybrid uni/multicasting. For the multicasting strategy, network coding is applied to maintain the same number of communication phases as for the other strategies. We address transceive beamforming maximising the sum rate of non-regenerative MGMW relaying. Due to the high complexity of finding the optimum transceive beamforming maximising the sum rate, we design generalised low complexity transceive beamforming algorithms for all BC strategies: matched filter, zero forcing, minimisation of mean square error and BC-strategy-aware transceive beamforming. It is shown that the sum rate performance of non-regenerative MGMW relaying depends both on the chosen BC strategies and the applied transceive beamforming at the RS.

关键词： Multi-way relaying Non-regenerative Multi-antenna analog network coding Transceive beamforming

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Throughput and Stability for Relay-Assisted Wireless Broadcast with network coding

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2013年第8期31卷 1506-1516页

作者： Sagduyu, Yalin E. Berry, Randall A. Guo, Dongning Intelligent Automat Inc Rockville MD 20855 USA Univ Maryland Syst Res Inst College Pk MD 20742 USA Northwestern Univ Dept Elect Engn & Comp Sci Evanston IL 60208 USA

The throughput and stability properties of wireless network coding are evaluated for an arbitrary number of terminals exchanging broadcast traffic with the aid of a relay. First, coding and scheduling schemes are derived that minimize the number of transmissions needed for each node to broadcast one packet. For stochastically varying traffic, the stable throughput is then compared under both digital and analog network coding schemes. The initial analysis focuses on a network with a single relay. Extensions to arbitrary terminal-relay configurations are then outlined for a general multihop network. Backpressure-like algorithms for jointly achieving throughput optimal scheduling and network coding are given for each network coding scheme.

关键词： Digital network coding analog network coding throughput delay stability network control

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Coordinated Direct and Relay Transmission With Linear Non-Regenerative Relay Beamforming

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IEEE SIGNAL PROCESSING LETTERS 2012年第10期19卷 680-683页

作者： Sun, Fan de Carvalho, Elisabeth Popovski, Petar Chan Dai Truyen Thai Aalborg Univ Dept Elect Syst DK-9220 Aalborg O Denmark

Joint processing of multiple communication flows in wireless systems has given rise to a number of novel transmission techniques, notably the two-way relaying, but also more general traffic scenarios, such as coordinated direct and relay (CDR) transmissions. In a CDR scheme the relay has a central role in managing the interference and boosting the overall system performance. In this letter we consider the case in which an amplify-and-forward relay has multiple antennas and can use beamforming to support the coordinated transmissions. We focus on one representative traffic type with one uplink user and one downlink user. Two different criteria for relay beamforming are analyzed: maximal weighted sum-rate and maximization of the worst-case weighted SNR. We propose iterative optimal solutions, as well as low-complexity near-optimal solutions.

关键词： analog network coding relay beamforming

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Secure Transmission in Cooperative networks with Weak Eavesdroppers

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IEEE SIGNAL PROCESSING LETTERS 2015年第10期22卷 1693-1697页

作者： Sunny, Albert Sarma, Siddhartha Kuri, Joy Indian Inst Sci Dept Elect Syst Engn Bangalore 560012 Karnataka India

In this letter, we propose a scheme to improve the secrecy rate of cooperative networks using analog network coding (ANC). ANC mixes the signals in the air;the desired signal is then separated out, from the mixed signals, at the legitimate receiver using techniques like self interference subtraction and signal nulling, thereby achieving better secrecy rates. Assuming global channel state information, memoryless adversaries and the decode-and-forward strategy, we seek to maximize the average secrecy rate between the source and the destination, subject to an overall power budget. Then, exploiting the structure of the optimization problem, we compute its optimal solution. Finally, we use numerical evaluations to compare our scheme with the conventional approaches.

关键词： analog network coding cooperative networks physical layer security power allocation weak adversaries

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Finite-SNR Diversity-Multiplexing Tradeoff for Three-Phase ANC with Channel Estimation Errors

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IEEE COMMUNICATIONS LETTERS 2014年第5期18卷 817-820页

作者： Yadav, Suneel Upadhyay, Prabhat K. Indian Inst Technol Indore Discipline Elect Engn Indore 452017 Madhya Pradesh India

In this letter, we analyze the diversity-multiplexing tradeoff (DMT) performance of a two-way relay system that employs three-phase (3P) analog network coding (ANC) in the presence of channel estimation errors under Nakagami-m fading. By deriving an overall system outage probability expression, we compute the DMT for the considered scheme at finite signal-to-noise ratios (SNRs). We further derive an asymptotic and limiting behavior of the DMT, from which the effect of imperfect estimation on the system achievable performance is highlighted. Numerical and simulation results corroborate our theoretical findings and provide a comparison of the tradeoffs for the 3P ANC over its two-phase (2P) counterpart.

关键词： analog network coding channel estimation DMT outage probability Nakagami-m fading two-way relaying

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